QuickLinks -- Click here to rapidly navigate through this document

Supplemental Information
(Unaudited)

March 31, 2002

Corporate Office Properties Trust
Index to Supplemental Information (Unaudited)
March 31, 2002

		Page
Highlights and Discussion
	Reporting Period Highlights—First Quarter 2002	1
	Subsequent Events	2
Financial Statements
	Quarterly Selected Financial Summary Data	3
	Quarterly Consolidated Balance Sheets	4
	Quarterly Consolidated Statements of Operations and Funds From Operations (FFO)	5
	Quarterly Consolidated Statements of Operations and FFO per Diluted Share	6
	Quarterly Consolidated Statements of Operations and FFO as a Percentage of Total Revenues	7
Selected Financial Analyses
	Quarterly Equity Analysis	8
	Quarterly Valuation Analysis	9
	Quarterly Debt Analysis	10
	Quarterly Operating Ratios	11
	Quarterly Dividend Analysis	12
	Investor Composition and Analyst Coverage	13
	Debt Maturity Schedule—March 31, 2002	14
Portfolio Summary
	Property Summary by Region—March 31, 2002	15
	Property Occupancy Rates by Region by Quarter	18
	Top Twenty Office Tenants as of March 31, 2002	19
	Total Rental Revenue and Net Operating Income by Geographic Region by Quarter	20
	Same Office Property Cash and GAAP Net Operating Income by Quarter	21
	Average Occupancy Rates by Region for Same Office Properties	22
	Office Lease Expiration Analysis by Year	23
	Quarterly Office Renewal Analysis	24
	Development Summary as of March 31, 2002	26
	Joint Venture Summary as of March 31, 2002	27

To Members of the Investment Community:

We prepared this supplemental information package to provide you with additional detail on our properties and operations. The information in this package is unaudited, filed with the Securities and Exchange Commission and should be read in conjunction with our quarterly and annual reports. If you have any questions or comments, please contact Ms. Mary Ellen Fowler, Vice President, Finance and Investor Relations at (410) 992-7324 or maryellen.fowler@copt.com.

Reporting Period Highlights—First Quarter 2002

Financial Results

•: Reported FFO—diluted of $11,373,000 or $.33 per share/unit for the first quarter of 2002 as compared to $10,102,000 or $.31 per share/unit for the comparable 2001 period, representing an increase of 6.5% per share/unit. FFO—diluted increased $1,271,000 or 12.6%, over the comparable 2001 period.
•: Reported AFFO—diluted of $9,541,000 or $.27 per share/unit for the first quarter of 2002 as compared to $8,296,000 or $.25 per share/unit for the comparable 2001 period, representing an increase of 8.0% per share/unit.
•: Our assets exceeded $1 billion as of March 31, 2002.

Financing and Capital Transactions

•: Constellation Real Estate, Inc., our largest shareholder, sold its entire ownership position of 8,876,172 common shares in a public offering at a price of $12.04 per share. As part of this offering, we also sold 2,084,828 common shares and realized gross proceeds of $25.1 million on March 5, 2002 which was used to repay outstanding debt. As a result, our common shares available to be publicly traded have doubled and our institutional ownership has almost tripled.
•: We expanded our Deutsche Bank revolving credit facility capacity from $125 to $150 million and added an option to extend the maturity date for a one-year period to March 31, 2005, subject to certain conditions.
•: As of March 31, 2002, our debt to market capitalization is 50.7% and our debt to undepreciated book value of real estate assets is 57.4%. We achieved an EBITDA interest coverage ratio of 2.7x and an EBITDA fixed charge coverage ratio of 2.0x for this quarter. Our quarterly weighted average interest rate dropped to 6.52% in the first quarter of 2002 from 6.85% in the prior quarter.
•: In January, BB&T Capital Markets initiated coverage of our stock with a Buy recommendation. As a result, we now have equity research coverage provided by seven analysts.

Operations

•: Our same property cash NOI increased by 4.1% over the quarter ended March 31, 2001 for the 82 properties comprising our same property portfolio. This improvement is primarily attributable to tighter control over operating costs.
•: Overall occupancy was 94% as of March 31, 2002. The occupancy rate was 93% in the Baltimore/Washington Corridor, which represents 61% of our office square footage and 64% of our total office revenues for the first quarter of 2002. We are 95% leased as of March 31, 2002.
•: Weighted average lease term of our office portfolio is 4.4 years as of March 31, 2002, with an average contractual rental rate (including tenant reimbursements of operating costs) of $18.52 per square foot.

Joint Ventures

•: On February 25, 2002, we acquired the remaining 50% joint venture interest in 2701 Technology Drive for $5.4 million and now directly own the 117,450 square foot property located in the National Business Park. As of March 31, 2002, this recently developed building was 100.0% leased. We simultaneously received $14.7 million of a $34.0 million, seven-year loan which bears interest at a fixed rate of 7.0% and repaid the joint venture's outstanding construction loan obligation of $10.0 million. $4.4 million of the remaining proceeds partially funded the $5.4 million payment noted above. The balance of the $34.0 million loan will be disbursed upon rent commencement of our 2711 Technology Drive property, which is anticipated in June 2002.
•: We acquired our joint venture partner's 20% interest in the 43,785 square foot operating property located in Montpelier Research Park for $326,000 on February 21, 2002. We simultaneously sold this property and realized a gain of $352,000.

Development

•: For the quarter, we signed three leases aggregating 71,693 square feet of development space at 1304 Concourse and 6724 Alexander Bell Drive.
•: In March, we sold 1362 Mellon Road, a development property, for a gain of $597,000.

Subsequent Events

•: In April, we acquired five buildings totaling 166,625 square feet located in the B/W Corridor for $16.3 million. These buildings are 98.3% occupied. Four of these buildings, totaling 109,449 square feet, contribute to our market concentration in the Howard County perimeter submarket where we now own 19 properties aggregating over 1.2 million square feet.
•: We executed two five-year leases totaling 71,243 square feet for 6731 Columbia Gateway Drive in April, increasing this building's leasing to 57.6%. Accordingly, our overall development pre-leasing has improved from 34.9% at year end to 57.0%.

Note: This supplemental information contains "forward looking" statements, as defined in the Private Securities Litigation Reform Act of 1995, that are based on the Company's current expectations, estimates and projections about future events and financial trends affecting the financial condition of the business. Statements that are not historical facts, including statements about the Company's beliefs and expectations, are forward-looking statements. These statements are not guarantees of future performance, events or results and involve potential risks and uncertainties. Accordingly, actual results may differ materially. The Company undertakes no obligations to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. For further information, please refer to the Company's filings with the Securities and Exchange Commission.

Quarterly Selected Financial Summary Data

(Dollars in thousands)

		2002			2001
		March 31			December 31			September 30			June 30			March 31
Total Revenues from Real Estate Operations		$	34,499		$	33,460		$	32,050		$	28,711		$	28,851
Net Operating Income from Real Estate Operations			24,306			23,358			22,394			20,153			20,385
EBITDA			22,919			22,731			21,411			20,471			19,490
Net Income before Preferred Dividends			5,295			5,893			5,222			5,081			3,726
Preferred Dividends			(2,533	)		(2,533	)		(1,830	)		(1,613	)		(881	)

Net Income Available to Common Shareholders		$	2,762		$	3,360		$	3,392		$	3,468		$	2,845

Funds From Operations (FFO)—Diluted		$	11,373		$	11,462		$	11,034		$	10,560		$	10,102
FFO per diluted share		$	0.33		$	0.34		$	0.33		$	0.32		$	0.31
Adjusted FFO—Diluted		$	9,541		$	8,560		$	9,106		$	8,591		$	8,296
Adjusted FFO per diluted share		$	0.27		$	0.25		$	0.27		$	0.26		$	0.25
Payout Ratios:
	FFO—Diluted^(A)		65.35	%		60.80	%		62.71	%		62.43	%		64.87	%
	AFFO—Diluted^(B)		77.90	%		81.41	%		75.98	%		76.73	%		78.99	%
Total Dividends/Distributions		$	9,829		$	9,366		$	8,613		$	8,069		$	7,334

(A): Computed by dividing total dividends/distributions (except for dividends on Series B, E and F Cumulative Redeemable Preferred Shares which are deducted to calculate FFO) by FFO diluted.
(B): Computed by dividing total dividends/distributions (except for dividends on Series B, E and F Cumulative Redeemable Preferred Shares which are deducted to calculate AFFO) by AFFO diluted.
Note: The above presentation does not separately report discontinued operations.

Quarterly Consolidated Balance Sheets

(Dollars in thousands except per share data)

			2002			2001
			March 31			December 31			September 30			June 30			March 31
Assets
Investment in real estate:
	Land—operational		$	165,685		$	164,994		$	157,789		$	142,461		$	140,620
	Land—development			29,544			26,751			23,507			24,488			24,683
	Construction in progress			38,140			37,493			33,860			30,066			22,228
	Buildings and improvements			755,597			738,320			682,474			624,635			615,586
	Investment in and advances to unconsolidated real estate joint ventures			10,740			11,047			8,005			12,009			6,877
	Less: accumulated depreciation			(57,245	)		(51,552	)		(46,361	)		(41,659	)		(37,652	)

		Net investment in real estate		942,461			927,053			859,274			792,000			772,342
	Cash and cash equivalents			4,250			6,640			7,881			2,962			3,806
	Restricted cash			6,977			4,947			4,116			9,633			4,468
	Accounts receivable, net			4,909			3,805			4,720			4,855			5,519
	Investment in and advances to other unconsolidated entities			2,105			2,112			1,939			2,041			2,159
	Deferred rent receivable			11,651			11,447			10,511			9,804			9,335
	Deferred charges, net			18,175			16,884			16,561			16,357			15,550
	Prepaid and other assets			10,991			9,551			8,145			9,383			6,726
	Furniture, fixtures and equipment, net of accumulated depreciation			1,717			1,771			1,699			1,772			1,807

		Total assets	$	1,003,236		$	984,210		$	914,846		$	848,807		$	821,712

Liabilities and beneficiaries' equity
Liabilities:
	Mortgage loans payable		$	573,821		$	573,327		$	508,715		$	475,999		$	478,913
	Accounts payable and accrued expenses			11,355			10,674			8,923			13,361			10,889
	Rents received in advance and security deposits			6,805			6,567			4,319			4,023			4,236
	Dividends/distributions payable			9,426			8,965			8,346			7,918			7,203
	Fair value of derivatives			2,720			3,781			3,894			2,232			1,993
	Other liabilities			7,171			12,193			11,082			10,637			10,243

		Total liabilities		611,298			615,507			545,279			514,170			513,477

Minority interests:
	Preferred Units in the Operating Partnership			24,367			24,367			24,367			24,367			24,367
	Common Units in the Operating Partnership			81,905			80,158			80,720			78,900			79,792
	Other consolidated partnerships			286			257			231			224			166

		Total minority interests		106,558			104,782			105,318			103,491			104,325

		Commitments and contingencies		—			—			—			—			—
Beneficiaries' equity:
	Preferred Shares ($0.01 par value; 10,000,000 authorized);
		40,693 designated as Series A Convertible Preferred Shares of beneficial interest (no shares issued as of March 31, 2002)		—			—			—			—			—
		1,725,000 designated as Series B Cumulative Redeemable Preferred Shares of beneficial interest (1,250,000 shares issued as of March 31, 2002)		13			13			13			13			13
		544,000 designated as Series D Cumulative Convertible Redeemable Preferred Shares of beneficial interest (544,000 shares issued as of March 31, 2002)		5			5			5			5			5
		1,265,000 designated as Series E Cumulative Redeemable Preferred Shares of beneficial interest (1,150,000 shares issued as of March 31, 2002)		11			11			11			11			—
		1,425,000 designated as Series F Cumulative Redeemable Preferred Shares of beneficial interest (1,425,000 shares issued as of March 31, 2002)		14			14			14			—			—
	Common Shares of beneficial interest ($0.01 par value; 45,000,000 authorized, 22,938,151 shares issued as of March 31, 2002)			229			208			208			207			206
	Treasury Shares, at cost (166,600 shares as of March 31, 2002)			(1,415	)		(1,415	)		(1,415	)		(1,415	)		(1,415	)
Additional paid-in capital				307,500			285,362			284,834			249,618			221,683
Cumulative dividends in excess of net income				(16,446	)		(14,502	)		(13,618	)		(12,776	)		(12,222	)
Value of unearned restricted Common Share grants				(2,739	)		(3,275	)		(3,229	)		(3,042	)		(3,042	)
Accumulated other comprehensive loss				(1,792	)		(2,500	)		(2,574	)		(1,475	)		(1,318	)

		Total beneficiaries' equity		285,380			263,921			264,249			231,146			203,910

		Total beneficiaries' equity and minority interests		391,938			368,703			369,567			334,637			308,235

		Total liabilities and beneficiaries' equity	$	1,003,236		$	984,210		$	914,846		$	848,807		$	821,712

Quarterly Consolidated Statements of Operations and Funds From Operations (FFO)

(Dollars and units in thousands)

			2002			2001
			March 31			December 31			September 30			June 30			March 31
Revenues
	Rental revenue		$	30,538		$	29,957		$	29,011		$	25,960		$	25,619
	Tenant recoveries and other revenue			3,961			3,503			3,039			2,751			3,232

		Total Revenues from Real Estate Operations		34,499			33,460			32,050			28,711			28,851
Expenses
	Property operating			4,473			4,243			4,178			3,492			3,448
	Repairs and maintenance			3,721			3,980			3,759			3,595			3,518
	Real estate taxes			1,999			1,879			1,719			1,471			1,500

		Total Property Expenses from Real Estate Operations		10,193			10,102			9,656			8,558			8,466
Net Operating Income from Real Estate Operations				24,306			23,358			22,394			20,153			20,385
	General and administrative			(2,170	)		(1,167	)		(1,347	)		(1,329	)		(1,446	)
	Equity in income of unconsol. real estate joint ventures			18			27			27			124			30
	Earnings from service companies			(90	)		(218	)		(378	)		143			(329	)
	Income from real estate services			855			731			715			1,380			850

EBITDA				22,919			22,731			21,411			20,471			19,490
	Interest expense			(8,648	)		(8,475	)		(8,342	)		(7,762	)		(8,194	)
	Series B, E & F Preferred Share dividends			(2,397	)		(2,397	)		(1,694	)		(1,477	)		(781	)
	Amortization of deferred financing costs			(486	)		(492	)		(397	)		(546	)		(383	)
	Income tax (expense) benefit			40			207			124			(44	)		122
	Expense (income) associated with options			14			—			5			—			(61	)
	Depreciation on unconsolidated real estate entities			64			40			38			70			(4	)
	Minority interestholders' share of operations			(31	)		(23	)		(7	)		(58	)		4
	Depreciation of corporate FF&E			(102	)		(129	)		(104	)		(94	)		(91	)

Funds From Operations (FFO)—Diluted				11,373			11,462			11,034			10,560			10,102
	Depreciation and other amortization			(6,539	)		(5,738	)		(5,148	)		(4,863	)		(4,809	)
	Gain on property sales			93			—			—			416			—
	Loss on early extinguishment of debt			(42	)		(7	)		—			(99	)		(106	)
	Cumulative effect adjustment for accounting change			—			—			—			—			(263	)
	Expense (income) associated with options			(14	)		—			(5	)		—			61
	Depreciation on unconsolidated real estate entities			(64	)		(40	)		(38	)		(70	)		4
	Minority interestholders' share of operations			31			23			7			58			(4	)
	Series B, E & F Preferred Share dividends			2,397			2,397			1,694			1,477			781

Income Before Minority Interests and Preferred Share Dividends				7,235			8,097			7,544			7,479			5,766
Minority Interests:
	Preferred Units in Operating Partnership			(572	)		(571	)		(572	)		(572	)		(572	)
	Common Units in Operating Partnership			(1,337	)		(1,610	)		(1,743	)		(1,768	)		(1,472	)
	Other consolidated entities			(31	)		(23	)		(7	)		(58	)		4
Preferred Share dividends				(2,533	)		(2,533	)		(1,830	)		(1,613	)		(881	)

Net Income Available to Common Shareholders			$	2,762		$	3,360		$	3,392		$	3,468		$	2,845

Funds From Operations (FFO)—Diluted			$	11,373		$	11,462		$	11,034		$	10,560		$	10,102
	Straight line rents			(214	)		(952	)		(717	)		(816	)		(690	)
	Non-incremental capital expenditures			(1,618	)		(1,950	)		(1,211	)		(1,153	)		(1,116	)

Adjusted Funds from Operations—Diluted			$	9,541		$	8,560		$	9,106		$	8,591		$	8,296

	Preferred dividends/distributions(1)			3,105			3,104			2,402			2,185			1,453
	Common dividends/distributions			6,724			6,262			6,211			5,884			5,881

Total Dividends/Distributions			$	9,829		$	9,366		$	8,613		$	8,069		$	7,334

(1): Includes Series B, E and F Cumulative Redeemable Preferred Share dividends deducted for FFO/AFFO computations.
Note:: The above presentation does not separately report discontinued operations.

Quarterly Consolidated Statements of Operations and FFO per Diluted Share

(Shares in thousands)

			2002			2001
			March 31			December 31			September 30			June 30			March 31
Revenues
	Rental revenue		$	0.87		$	0.88		$	0.86		$	0.78		$	0.78
	Tenant recoveries and other revenue			0.11			0.10			0.09			0.08			0.10

		Total Revenues from Real Estate Operations		0.99			0.98			0.95			0.86			0.88
Expenses
	Property operating			0.13			0.12			0.12			0.10			0.10
	Repairs and maintenance			0.11			0.12			0.11			0.11			0.11
	Real estate taxes			0.06			0.06			0.05			0.04			0.05

		Total Property Expenses from Real Estate Operations		0.29			0.30			0.29			0.26			0.26
Net Operating Income from Real Estate Operations				0.70			0.69			0.67			0.60			0.62
	General and administrative			(0.06	)		(0.03	)		(0.04	)		(0.04	)		(0.04	)
	Equity in income of unconsol. real estate joint ventures			0.00			0.00			0.00			0.00			0.00
	Earnings from service companies			(0.00	)		(0.01	)		(0.01	)		0.00			(0.01	)
	Income from real estate services			0.02			0.02			0.02			0.04			0.03

EBITDA				0.66			0.67			0.64			0.61			0.59
	Interest expense			(0.25	)		(0.25	)		(0.25	)		(0.23	)		(0.25	)
	Series B, E & F Preferred Share dividends			(0.07	)		(0.07	)		(0.05	)		(0.04	)		(0.02	)
	Amortization of deferred financing costs			(0.01	)		(0.01	)		(0.01	)		(0.02	)		(0.01	)
	Income tax (expense) benefit			0.00			0.01			0.00			(0.00	)		0.00
	Expense (income) associated with options			0.00			—			0.00			—			(0.00	)
	Depreciation on unconsolidated real estate entities			0.00			0.00			0.00			0.00			(0.00	)
	Minority interestholders' share of operations			(0.00	)		(0.00	)		(0.00	)		(0.00	)		0.00
	Depreciation of corporate FF&E			(0.00	)		(0.00	)		(0.00	)		(0.00	)		(0.00	)

Funds From Operations (FFO)—Diluted				0.33			0.34			0.33			0.32			0.31
	Depreciation and other amortization			(0.19	)		(0.17	)		(0.15	)		(0.15	)		(0.15	)
	Gain on property sales			0.00			—			—			0.01			—
	Loss on early extinguishment of debt			(0.00	)		(0.00	)		—			(0.00	)		(0.00	)
	Cumulative effect adjustment for accounting change			—			—			—			—			(0.01	)
	Expense (income) associated with options			(0.00	)		—			(0.00	)		—			0.00
	Depreciation on unconsolidated real estate entities			(0.00	)		(0.00	)		(0.00	)		(0.00	)		0.00
	Minority interestholders' share of operations			0.00			0.00			0.00			0.00			(0.00	)
	Series B, E & F Preferred Share dividends			0.07			0.07			0.05			0.04			0.02

Income Before Minority Interests and Preferred Share Dividends				0.21			0.24			0.22			0.22			0.18
Minority Interests:
	Preferred Units in Operating Partnership			(0.02	)		(0.02	)		(0.02	)		(0.02	)		(0.02	)
	Common Units in Operating Partnership			(0.04	)		(0.05	)		(0.05	)		(0.05	)		(0.04	)
	Other consolidated entities			(0.00	)		(0.00	)		(0.00	)		(0.00	)		0.00
Preferred Share dividends				(0.07	)		(0.07	)		(0.05	)		(0.05	)		(0.03	)

Net Income Available to Common Shareholders			$	0.08		$	0.10		$	0.10		$	0.10		$	0.09

Funds From Operations (FFO)—Diluted			$	0.33		$	0.34		$	0.33		$	0.32		$	0.31
	Straight line rents			(0.01	)		(0.03	)		(0.02	)		(0.02	)		(0.02	)
	Non-incremental capital expenditures			(0.05	)		(0.06	)		(0.04	)		(0.03	)		(0.03	)

Adjusted Funds from Operations—Diluted			$	0.27		$	0.25		$	0.27		$	0.26		$	0.25

For FFO Computations:
Weighted Average Converted Preferred Shares/Units				3,618			3,618			3,618			3,618			3,299
Weighted Average Common Shares/Units Outstanding				31,324			30,385			30,037			29,746			29,643

Weighted Average Diluted Shares Outstanding				34,942			34,003			33,655			33,364			32,942

Quarterly Consolidated Statements of Operations and FFO as a Percentage of Total Revenues

			2002		2001
			March 31		December 31		September 30		June 30		March 31
Revenues
	Rental revenue		89	%	90	%	91	%	90	%	89	%
	Tenant recoveries and other revenue		11	%	10	%	9	%	10	%	11	%

		Total Revenues from Real Estate Operations	100	%	100	%	100	%	100	%	100	%
Expenses
	Property operating		13	%	13	%	13	%	12	%	12	%
	Repairs and maintenance		11	%	12	%	12	%	13	%	12	%
	Real estate taxes		6	%	6	%	5	%	5	%	5	%

		Total Property Expenses from Real Estate Operations	30	%	30	%	30	%	30	%	29	%
Net Operating Income from Real Estate Operations			70	%	70	%	70	%	70	%	71	%
	General and administrative		(6	)%	(3	)%	(4	)%	(5	)%	(5	)%
	Equity in income of unconsol. real estate joint ventures		0	%	0	%	0	%	0	%	0	%
	Earnings from service companies		(0	)%	(1	)%	(1	)%	0	%	(1	)%
	Income from real estate services		2	%	2	%	2	%	5	%	3	%

EBITDA			66	%	68	%	67	%	71	%	68	%
	Interest expense		(25	)%	(25	)%	(26	)%	(27	)%	(28	)%
	Series B, E & F Preferred Share dividends		(7	)%	(7	)%	(5	)%	(5	)%	(3	)%
	Amortization of deferred financing costs		(1	)%	(1	)%	(1	)%	(2	)%	(1	)%
	Income tax (expense) benefit		0	%	1	%	0	%	(0	)%	0	%
	Expense (income) associated with options		0	%	0	%	0	%	0	%	(0	)%
	Depreciation on unconsolidated real estate entities		0	%	0	%	0	%	0	%	(0	)%
	Minority interestholders' share of operations		(0	)%	(0	)%	(0	)%	(0	)%	0	%
	Depreciation of corporate FF&E		(0	)%	(0	)%	(0	)%	(0	)%	(0	)%

Funds From Operations (FFO)—Diluted			33	%	34	%	34	%	37	%	35	%
	Depreciation and other amortization		(19	)%	(17	)%	(16	)%	(17	)%	(17	)%
	Gain on property sales		0	%	0	%	0	%	1	%	0	%
	Loss on early extinguishment of debt		(0	)%	(0	)%	0	%	(0	)%	(0	)%
	Cumulative effect adjustment for accounting change		0	%	0	%	0	%	0	%	(1	)%
	Expense (income) associated with options		(0	)%	0	%	(0	)%	0	%	0	%
	Depreciation on unconsolidated real estate entities		(0	)%	(0	)%	(0	)%	(0	)%	0	%
	Minority interestholders' share of operations		0	%	0	%	0	%	0	%	(0	)%
	Series B, E & F Preferred Share dividends		7	%	7	%	5	%	5	%	3	%

Income Before Minority Interests and Preferred Share Dividends			21	%	24	%	24	%	26	%	20	%
Minority Interests:
	Preferred Units in Operating Partnership		(2	)%	(2	)%	(2	)%	(2	)%	(2	)%
	Common Units in Operating Partnership		(4	)%	(5	)%	(5	)%	(6	)%	(5	)%
	Other consolidated entities		(0	)%	(0	)%	(0	)%	(0	)%	0	%
Preferred Share dividends			(7	)%	(8	)%	(6	)%	(6	)%	(3	)%

Net Income Available to Common Shareholders			8	%	10	%	11	%	12	%	10	%

Funds From Operations (FFO)—Diluted			33	%	34	%	34	%	37	%	35	%
	Straight line rents		(1	)%	(3	)%	(2	)%	(3	)%	(2	)%
	Non-incremental capital expenditures		(5	)%	(6	)%	(4	)%	(4	)%	(4	)%
Adjusted Funds from Operations—Diluted			28	%	26	%	28	%	30	%	29	%

Quarterly Equity Analysis

(Amounts in thousands, except per share data, share prices and ratios)

		2002			2001
		March 31			December 31			September 30			June 30			March 31
Common Equity—End of Quarter
	Common Shares⁽¹⁾		22,772			20,648			20,590			20,526			20,429
	Common Units		9,607			9,607			9,617			9,307			9,388

	Total		32,379			30,255			30,207			29,833			29,817

Convertible Preferred Equity—End of Quarter
	Convertible Series A Preferred Shares Outstanding		n/a			0			0			0			0
	Conversion Ratio		n/a			1.8748			1.8748			1.8748			1.8748
	Common Shares Issued Assuming Conversion		n/a			0			0			0			0
	Preferred Share Liquidation Preference		n/a		$	25.00		$	25.00		$	25.00		$	25.00
	Convertible Series D Preferred Shares Outstanding⁽²⁾		544			544			544			544			544
	Conversion Ratio		2.2000			2.2000			2.2000			2.2000			2.2000
	Common Shares Issued Assuming Conversion		1,197			1,197			1,197			1,197			1,197
	Preferred Share Liquidation Preference	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
	Convertible Series C Preferred Units Outstanding		1,017			1,017			1,017			1,017			1,017
	Conversion Ratio		2.3810			2.3810			2.3810			2.3810			2.3810
	Common Units Issued Assuming Conversion		2,421			2,421			2,421			2,421			2,421
	Preferred Share Liquidation Preference	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
Perpetual Preferred Equity—End of Quarter
	Redeemable Series B Shares Outstanding		1,250			1,250			1,250			1,250			1,250
	Preferred Share Liquidation Preference	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
	Redeemable Series E Shares Outstanding⁽³⁾		1,150			1,150			1,150			1,150			n/a
	Preferred Share Liquidation Preference	$	25.00		$	25.00		$	25.00		$	25.00			n/a
	Redeemable Series F Shares Outstanding⁽⁴⁾		1,425			1,425			1,425			n/a			n/a
	Preferred Share Liquidation Preference	$	25.00		$	25.00		$	25.00			n/a			n/a
Weighted Average Shares:
	Weighted Average Common Shares Outstanding		20,889			20,186			20,141			20,077			19,982
	Weighted Average Preferred Shares Outstanding Assuming Conversion		1,197			1,197			1,197			1,197			878
	Weighted Average Dilutive Options		828			590			481			334			273
	Weighted Average Common Units		9,607			9,609			9,415			9,335			9,388
	Weighted Average Preferred Units Assuming Conversion		2,421			2,421			2,421			2,421			2,421

Weighted Avg. Shares/Units Outstanding Assuming Conversion of Preferred Shares/Units			34,942			34,003			33,655			33,364			32,942

Common Shares Trading Volume
	Average Daily Volume (Shares)		116			23			30			24			21
	Average Daily Volume (Dollars in thousands)	$	1,460.22		$	261.76		$	313.45		$	237.66		$	198.00
	As a Percentage of Common Shares		0.6	%		0.1	%		0.1	%		0.1	%		0.1	%
Common Share Price Range
	Quarterly High	$	13.20		$	12.71		$	11.50		$	10.60		$	9.98
	Quarterly Low	$	11.62		$	10.75		$	9.86		$	9.36		$	9.03
	Quarterly Average	$	12.54		$	11.50		$	10.61		$	10.10		$	9.59
	End of Quarter	$	13.10		$	11.87		$	10.90		$	10.00		$	9.51
Capitalization
	Liquidation Value of Preferred Shares/Units	$	134,642		$	134,642		$	134,642		$	99,017		$	70,267
	Market Value of Common Shares/Units		424,165			359,127			329,256			298,330			283,560

	Total Equity Market Capitalization	$	558,806		$	493,768		$	463,898		$	397,347		$	353,826

	Total Debt	$	573,821		$	573,327		$	508,715		$	475,999		$	478,913

	Total Market Capitalization	$	1,132,627		$	1,067,095		$	972,613		$	873,346		$	832,739

Debt to Total Market Capitalization			50.7	%		53.7	%		52.3	%		54.5	%		57.5	%
Debt to Undepreciated Book Value of Real Estate Assets			57.4	%		58.6	%		56.2	%		57.1	%		59.1	%

(1): Net of 166,600 treasury shares as of March 31, 2002. Includes 2,084,828 common shares issued on March 5, 2002.
(2): We issued 544,000 Convertible Series D preferred shares on January 25, 2001.
(3): We issued 1,150,000 Cumulative Redeemable Series E preferred shares on April 6, 2001.
(4): We issued 1,425,000 Cumulative Redeemable Series F preferred shares on September 13, 2001.

Quarterly Valuation Analysis

(Dollars in thousands except per share data and ratios)

	2002			2001
	March 31			December 31			September 30			June 30			March 31
PRICING MULTIPLES
NOI Multiple (Market value of Common Equity + Avg. Preferred Share/Units+ Avg. Total Debt) / Ann. NOI		11.70	x		11.00	x		10.93	x		10.82	x		10.17	x
EBITDA Multiple (Market value of Common Equity + Avg. Preferred Share/Units + Avg. Total Debt) / Ann. EBITDA		12.41	x		11.30	x		11.43	x		10.66	x		10.64	x
FFO Multiple (Quarter End Common Share Price / Ann. FFO—diluted)		10.06	x		8.80	x		8.31	x		7.90	x		7.75	x
AFFO Multiple (Quarter End Common Share Price / Ann. AFFO—diluted)		11.99	x		11.79	x		10.07	x		9.71	x		9.44	x
NOI Yield (Ann. NOI / (Market value of Common Equity + Avg. Preferred Share/Units + Avg. Debt))		8.54	%		9.09	%		9.15	%		9.24	%		9.83	%
EBITDA Yield (Ann. EBITDA / (Market value of Common Equity + Avg. Preferred Share/Units + Avg. Debt))		8.06	%		8.85	%		8.75	%		9.38	%		9.40	%
FFO Yield (Ann. FFO / Quarter End Common Share Price)		9.94	%		11.36	%		12.03	%		12.66	%		12.90	%
AFFO Yield (Ann. AFFO / Quarter End Common Share Price)		8.34	%		8.48	%		9.93	%		10.30	%		10.59	%
Total Market Capitalization Per Square Foot ((Market Value of Common Stock + Preferred Share/Units + Total Debt) / GLA)⁽¹⁾	$	145.61		$	137.76		$	133.34		$	129.22		$	124.70
RETURNS
Yield on Real Estate Owned—NOI (Ann. NOI / Avg. Adjusted Gross Real Estate Investment)⁽²⁾		10.65	%		10.71	%		11.12	%		10.54	%		10.85	%
Yield on Real Estate Owned—EBITDA (Ann. EBITDA / Avg. Adjusted Gross Real Estate Investment)⁽²⁾		10.04	%		10.42	%		10.63	%		10.71	%		10.37	%
Return on Book Value of Average Equity & Minority Interest (Ann. EBTDA / Avg. Equity & Minority Interest)		15.01	%		15.45	%		14.85	%		15.82	%		14.87	%

(1): Excludes square footage of assets under development, under construction or held in a joint venture.
(2): Excludes land-development, construction in progress and investment in development real estate joint ventures as these assets are not yet income generating.

Quarterly Debt Analysis

(Dollars in thousands)

		2002			2001
		March 31			December 31			September 30			June 30			March 31
Debt Outstanding
	Mortgage Loans	$	462,287		$	445,951		$	475,163		$	409,670		$	356,872
	Construction Loans		17,534			17,376			15,852			13,099			18,950
	Revolving Credit Facility		—			—			—			—			29,091
	Secured Revolving Credit Facility		94,000			110,000			17,700			53,230			74,000

		$	573,821		$	573,327		$	508,715		$	475,999		$	478,913

Average Outstanding Balance
	Mortgage Loans	$	452,987		$	428,231		$	446,784		$	377,222		$	344,023
	Construction Loans		17,431			16,648			15,502			10,436			26,967
	Revolving Credit Facility		—			—			—			28,445			29,091
	Secured Revolving Credit Facility		108,581			89,110			52,548			59,123			75,507

		$	578,999		$	533,989		$	514,834		$	475,226		$	475,588

Interest Rate Structure
	Fixed	$	340,037		$	326,701		$	328,029		$	305,431		$	240,501
	Variable		83,784			96,626			—			—			13,412
	Variable Subject to Interest Rate Protection^(1-4)		150,000			150,000			180,686			170,568			225,000

		$	573,821		$	573,327		$	508,715		$	475,999		$	478,913

	% of Fixed Rate Loans^(A)		59.26	%		56.98	%		64.48	%		64.17	%		50.22	%
	% of Variable Rate Loans		40.74	%		43.02	%		35.52	%		35.83	%		49.78	%

			100.00	%		100.00	%		100.00	%		100.00	%		100.00	%

Average Interest Rates
	Mortgage & Construction Loans		6.37	%		6.71	%		7.12	%		7.31	%		7.44	%
	Revolving Credit Facility		n/a			n/a			n/a			6.71	%		7.31	%
	Secured Revolving Credit Facility		7.21	%		7.32	%		6.73	%		6.93	%		7.85	%
	Total Weighted Average		6.52	%		6.85	%		7.08	%		7.22	%		7.50	%
Debt Ratios
Debt to Total Market Capitalization			50.7	%		53.7	%		52.3	%		54.5	%		57.5	%
Debt to Undepreciated Book Value of Real Estate Assets			57.4	%		58.6	%		56.2	%		57.1	%		59.1	%
Coverage Ratios (excluding capitalized interest)
	Interest Coverage—NOI (NOI / Interest)		2.81	x		2.76	x		2.68	x		2.60	x		2.49	x
Interest Coverage—EBITDA (EBITDA / Interest)			2.65	x		2.68	x		2.57	x		2.64	x		2.38	x
Interest Coverage—EBITDA—YTD (EBITDA / Interest—Year-to-date)			2.65	x		2.57	x		2.53	x		2.50	x		2.38	x
Debt Service Coverage—NOI (NOI / (Interest + Principal Amortization))			2.43	x		2.38	x		2.32	x		2.28	x		2.23	x
Debt Service Coverage—EBITDA (EBITDA / (Interest + Principal Amortization))			2.29	x		2.31	x		2.22	x		2.32	x		2.13	x
Fixed Charge Coverage—NOI (NOI / (Interest + Preferred Distribution))			2.07	x		2.02	x		2.08	x		2.03	x		2.11	x
Fixed Charge Coverage—EBITDA (EBITDA / (Interest + Preferred Distribution))			1.95	x		1.96	x		1.99	x		2.06	x		2.02	x

(A): Excludes interest rate protection agreements.
(1): We purchased a $50 million 2-year cap on LIBOR at a rate of 7.7% which expires May 31, 2002.
(2): We purchased a $50 million 1-year cap on LIBOR at a rate of 7.0% which expired October 13, 2001.
(3): We purchased a $25 million 1-year cap on LIBOR at a rate of 7.0% which expired October 13, 2001.
(4): We executed a $100 million notional amount swap exchanging 30-day floating LIBOR for LIBOR of 5.76% over a two-year period which expires January 2, 2003.

Quarterly Operating Ratios

(Dollars in thousands except per share data and ratios)

		2002			2001
		March 31			December 31			September 30			June 30			March 31
OPERATING RATIOS
NOI as a % of Real Estate Revenues
	(NOI / (Rental Revenue + Oper. Expense Reimb.))		70.45	%		69.81	%		69.87	%		70.19	%		70.66	%
EBITDA as a % of Real Estate Revenues
	(EBITDA / (Rental Revenue + Oper. Expense Reimb.))		66.43	%		67.93	%		66.80	%		71.30	%		67.55	%
G&A as a % of Real Estate Revenues
	(G&A / (Rental Revenue + Oper. Expense Reimb.))		6.29	%		3.49	%		4.20	%		4.63	%		5.01	%
G&A as a % of EBITDA
	(G&A / EBITDA)		9.47	%		5.13	%		6.29	%		6.49	%		7.42	%
Quarter end occupancy for operating portfolio			93.92	%		96.07	%		97.18	%		96.92	%		96.95	%
Quarter end % leased for operating portfolio			94.70	%		96.59	%		97.57	%		97.60	%		98.39	%
Non-Incremental Capital Expenditures		$	1,618		$	1,950		$	1,211		$	1,153		$	1,116
Non-Incremental Capital Expenditures per average square foot		$	0.21		$	0.26		$	0.17		$	0.17		$	0.17
Non-Incremental Capital Expenditures per Diluted Share		$	0.05		$	0.06		$	0.04		$	0.03		$	0.03
Non-Incremental Capital Expenditures as a % of NOI			6.66	%		8.35	%		5.41	%		5.72	%		5.47	%

Quarterly Dividend Analysis

		2002			2001
		March 31			December 31			September 30			June 30			March 31
Common Share Dividends
	Dividends per share/unit	$	0.21		$	0.21		$	0.21		$	0.20		$	0.20
	Increase over prior quarter		0.0	%		0.0	%		5.0	%		0.0	%		0.0	%
	Increase over prior year		5.0	%		5.0	%		5.0	%		5.3	%		5.3	%
Common Dividend Payout Ratios
	Payout—FFO—Diluted ((Dividend + Distributions)/FFO)		65.3	%		60.8	%		62.7	%		62.4	%		64.9	%
Payout—AFFO—Diluted (Dividend /FAD)			77.9	%		81.4	%		76.0	%		76.7	%		79.0	%
Dividend Coverage—FFO—Diluted (FFO /dividends)			1.53	x		1.64	x		1.59	x		1.60	x		1.54	x
Dividend Coverage—AFFO—Diluted (AFFO /dividends)			1.28	x		1.23	x		1.32	x		1.30	x		1.27	x
Common Dividend Yields
	Dividend Yield		6.41	%		7.08	%		7.71	%		8.00	%		8.41	%
Series C Preferred Unit Distributions
	Preferred Unit Distributions Per Share	$	0.56250		$	0.56250		$	0.56250		$	0.56250		$	0.56250
	Preferred Unit Distributions Yield		9.00	%		9.00	%		9.00	%		9.00	%		9.00	%
	Quarter End Liquidation Preference	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
Series A Preferred Share Dividends⁽¹⁾
	Preferred Share Dividends Per Share		n/a		$	0.34375		$	0.34375		$	0.34375		$	0.34375
	Preferred Share Dividend Yield		n/a			5.50	%		5.50	%		5.50	%		5.50	%
	Quarter End Liquidation Preference		n/a		$	25.00		$	25.00		$	25.00		$	25.00
Series B Preferred Share Dividends
	Preferred Share Dividends Per Share	$	0.62500		$	0.62500		$	0.62500		$	0.62500		$	0.62500
	Preferred Share Dividend Yield		10.00	%		10.00	%		10.00	%		10.00	%		10.00	%
	Quarter End Liquidation Preference	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
Series D Preferred Share Dividends⁽²⁾
	Preferred Share Dividends Per Share	$	0.25000		$	0.25000		$	0.25000		$	0.25000		$	0.25000
	Preferred Share Dividend Yield		4.00	%		4.00	%		4.00	%		4.00	%		4.00	%
	Quarter End Liquidation Preference	$	25.00		$	25.00		$	25.00		$	25.00		$	25.00
Series E Preferred Share Dividends⁽³⁾
	Preferred Share Dividends Per Share	$	0.64063		$	0.64063		$	0.64063		$	0.64063			n/a
	Preferred Share Dividend Yield		10.25	%		10.25	%		10.25	%		10.25	%		n/a
	Quarter End Liquidation Preference	$	25.00		$	25.00		$	25.00		$	25.00			n/a
Series F Preferred Share Dividends⁽⁴⁾
	Preferred Share Dividends Per Share	$	0.61719		$	0.61719		$	0.61719			n/a			n/a
	Preferred Share Dividend Yield		9.875	%		9.875	%		9.875	%		n/a			n/a
	Quarter End Liquidation Preference	$	25.00		$	25.00		$	25.00			n/a			n/a

(1): On March 5, 2002, Constellation converted its Series A Preferred Share and then sold its entire common share ownership position.
(2): We issued 544,000 of Series D Convertible Preferred Shares on January 25, 2001. Dividend was prorated based upon the number of days outstanding from date of issuance through quarter end. Prorated dividend was $.1833 per share.
(3): We issued 1,150,000 of Series E Cumulative Redeemable Preferred Shares on April 6, 2001. Dividend was prorated based upon the number of days outstanding from date of issuance through quarter end. Prorated dividend was $.6050 per share.
(4): We issued 1,425,000 of Series F Cumulative Redeemable Preferred Shares on September 13, 2001. Dividend was prorated based upon the number of days outstanding from date of issuance through quarter end. Prorated dividend was $.123435 per share.

Investor Composition and Analyst Coverage

(as of March 31, 2002)

SHAREHOLDER CLASSIFICATION	Common Shares	Common Units	As if Converted Preferred Shares / Units	Total	Fully Diluted Ownership % of Total
Insiders	1,150,278	7,831,137	—	8,981,415	24.95	%
Institutional Ownership	8,388,815	—	3,617,472	12,006,287	33.35	%
Other / Retail	13,232,457	1,776,222	—	15,008,679	41.69	%

	22,771,550	9,607,359	3,617,472	35,996,381	100.00	%

RESEARCH COVERAGE	March 31, 2002	December 31, 2001	September 30, 2001	June 30, 2001	March 31, 2001
A. G. Edwards	x	x	x	x	x
BB&T Capital Markets	x	n/a	n/a	n/a	n/a
Credit Suisse First Boston	x	x	x	x	x
Deutsche Banc Alex. Brown	x	x	x	x	x
Ferris, Baker Watts, Incorporated	x	x	x	x	x
Janney Montgomery Scott	n/a	x	x	x	x
Legg Mason Wood Walker, Inc.	x	x	x	x	x
McDonald Investments	x	x	x	x	x

Source: Institutional ownership was obtained from filed Forms 13(f) as of December 31, 2001 per Vickers Stock Research Corporation. For the March 5, 2002 common share offering, an institutional ownership analysis was provided by the joint lead managers.

Debt Maturity Schedule—March 31, 2002

(Dollars in thousands)

	Mortgages				Construction Loans⁽¹⁾
Year of Maturity	Annual Amortization of Monthly Payments		Due on Maturity		Annual Amortization of Monthly Payments		Due on Maturity⁽²⁾		$150,000 Secured Revolving Credit Facility⁽³⁾		Total Scheduled Payments
April - Dec. 2002	$	4,490	$	50,000	$	119	$	—	$	—	$	54,609
2003		6,493		25,121		172		17,243		—		49,029
2004		7,137		46,315		—		—		—		53,452
2005		6,899		41,567		—		—		94,000		142,466
2006		6,446		59,975		—		—		—		66,421
2007		5,417		20,377		—		—		—		25,794
2008		3,677		142,737		—		—		—		146,414
2009		447		35,189		—		—		—		35,636

	$	41,006	$	421,281	$	291	$	17,243	$	94,000	$	573,821

Notes:

(1): The construction loan balances as of March 31, 2002 represent the outstanding balances as of that date.
(2): We have the right to extend construction loans of $10,489 and $7,045, for a one-year period subject to certain conditions, upon maturity in July 2002. The above table reflects the maturities in 2003, as if the loans had been extended.
(3): We have the right to extend the Secured Revolving Credit Facility for a one-year period, subject to certain conditions, upon maturity in March 2004. The extended maturity date has been presented above.

We have obtained interest rate protection agreements as follows:

$50 million cap on thirty-day LIBOR at 7.7% expiring in May 2002.

$100 million notional amount swap of thirty-day LIBOR at 5.76% expiring in January 2003.

Property Summary by Region—March 31, 2002

Operating Property Count		Owned or Joint Venture (JV)	Submarket	State	Year Built or Renovated	Single Story (S) or Multi-story (M)	Total Operational Square Feet	Total Square Feet Under Development
	Office Properties Baltimore /Washington Corridor
1	2730 Hercules Road	Owned	BWI Airport	MD	1990	M	240,336
2	132 National Business Parkway	Owned	BWI Airport	MD	2000	M	118,456
3	2721 Technology Drive (221 NBP)	Owned	BWI Airport	MD	2000	M	118,093
4	2701 Technology Drive (201 NBP)	Owned	BWI Airport	MD	2001	M	91,643	25,807
5	1306 Concourse Drive	Owned	BWI Airport	MD	1990	M	114,046
6	1304 Concourse Drive	Owned	BWI Airport	MD	2002	M	10,657	92,307
7	870-880 Elkridge Landing Road	Owned	BWI Airport	MD	1981	M	97,161
8	900 Elkridge Landing Road	Owned	BWI Airport	MD	1982	M	97,139
9	1199 Winterson Road	Owned	BWI Airport	MD	1988	M	96,636
10	920 Elkridge Landing Road	Owned	BWI Airport	MD	1982	M	96,566
11	134 National Business Parkway	Owned	BWI Airport	MD	1999	M	93,482
12	133 National Business Parkway	Owned	BWI Airport	MD	1997	M	88,666
13	141 National Business Parkway	Owned	BWI Airport	MD	1990	M	86,964
14	135 National Business Parkway	Owned	BWI Airport	MD	1998	M	86,863
15	1302 Concourse Drive	Owned	BWI Airport	MD	1996	M	84,607
16	7467 Ridge Road	Owned	BWI Airport	MD	1990	M	73,756
17	881 Elkridge Landing Road	Owned	BWI Airport	MD	1986	M	73,572
18	7240 Parkway Drive	Owned	BWI Airport	MD	1985	M	74,156
19	1099 Winterson Road	Owned	BWI Airport	MD	1988	M	70,938
20	131 National Business Parkway	Owned	BWI Airport	MD	1990	M	68,906
21	1190 Winterson Road	Owned	BWI Airport	MD	1987	M	68,567
22	849 International Drive	Owned	BWI Airport	MD	1988	M	68,397
23	911 Elkridge Landing Road	Owned	BWI Airport	MD	1985	M	68,296
24	1201 Winterson Road	Owned	BWI Airport	MD	1985	M	67,903
25	999 Corporate Boulevard	Owned	BWI Airport	MD	2000	M	67,351
26	7318 Parkway Drive	Owned	BWI Airport	MD	1984	S	59,204
27	900 International Drive	Owned	BWI Airport	MD	1986	S	57,140
28	930 International Drive	Owned	BWI Airport	MD	1986	S	57,140
29	901 Elkridge Landing Road	Owned	BWI Airport	MD	1984	M	57,130
30	891 Elkridge Landing Road	Owned	BWI Airport	MD	1984	M	56,489
31	921 Elkridge Landing Road	Owned	BWI Airport	MD	1983	M	54,057
32	939 Elkridge Landing Road	Owned	BWI Airport	MD	1983	M	53,031
33	938 Elkridge Landing Road	Owned	BWI Airport	MD	1984	M	52,988
34	940 Elkridge Landing Road	Owned	BWI Airport	MD	1984	M	51,704
35	800 International Drive	Owned	BWI Airport	MD	1988	S	50,979
36	1340 Ashton Road	Owned	BWI Airport	MD	1989	S	46,400
37	7321 Parkway Drive	Owned	BWI Airport	MD	1984	S	39,822
38	1334 Ashton Road	Owned	BWI Airport	MD	1989	S	37,565
39	1331 Ashton Road	Owned	BWI Airport	MD	1989	S	29,936
40	1350 Dorsey Road	Owned	BWI Airport	MD	1989	S	19,992
41	1344 Ashton Road	Owned	BWI Airport	MD	1989	M	16,865
42	1341 Ashton Road	Owned	BWI Airport	MD	1989	S	15,841
43	1343 Ashton Road	Owned	BWI Airport	MD	1989	S	9,962
44	114 National Business Parkway	Owned	BWI Airport	MD	2002	S	9,717
	2711 Technology Drive (211 NBP)	JV	BWI Airport	MD		M		150,000

	Subtotal (continued on next page)						2,999,119	268,114

Property Summary by Region—March 31, 2002 (Continued)

Operating Property Count		Owned or Joint Venture (JV)	Submarket	State	Year Built or Renovated	Single Story (S) or Multi-story (M)	Total Operational Square Feet	Total Square Feet Under Development
	Subtotal (continued from prior page)						2,999,119	268,114
45	1615 and 1629 Thames Street	Owned	Baltimore City	MD	1989	M	103,683
46	9690 Deereco Road	Owned	North Baltimore Co.	MD	1988	M	133,737
47	375 West Padonia Road	Owned	North Baltimore Co.	MD	1986	M	100,804
48	7200 Riverwood Drive	Owned	Howard Co. Perimeter	MD	1986	S	160,000
49	9140 Route 108	Owned	Howard Co. Perimeter	MD	1974/1985	S	150,000
50	6940 Columbia Gateway Drive	Owned	Howard Co. Perimeter	MD	1999	M	108,737
51	6950 Columbia Gateway Drive	Owned	Howard Co. Perimeter	MD	1998	M	107,778
52	7067 Columbia Gateway Drive	Owned	Howard Co. Perimeter	MD	2001	M	82,953
53	6750 Alexander Bell Drive	Owned	Howard Co. Perimeter	MD	2001	M	78,460
54	6700 Alexander Bell Drive	Owned	Howard Co. Perimeter	MD	1988	M	75,635
55	6740 Alexander Bell Drive	Owned	Howard Co. Perimeter	MD	1992	M	61,957
56	8815 Centre Park Drive	Owned	Howard Co. Perimeter	MD	1987	M	53,782
57	6716 Alexander Bell Drive	Owned	Howard Co. Perimeter	MD	1990	M	52,002
58	7065 Columbia Gateway Drive	Owned	Howard Co. Perimeter	MD	2000	S	38,560
59	6760 Alexander Bell Drive	Owned	Howard Co. Perimeter	MD	1991	M	37,248
60	7063 Columbia Gateway Drive	Owned	Howard Co. Perimeter	MD	2000	S	36,936
61	6708 Alexander Bell Drive	Owned	Howard Co. Perimeter	MD	1988	M	35,040
62	7061 Columbia Gateway Drive	Owned	Howard Co. Perimeter	MD	2000	M	29,604
	6731 Columbia Gateway Drive	Owned	Howard Co. Perimeter	MD		M		123,743
	Robert Fulton Drive—Phase I	JV	Howard Co. Perimeter	MD		M		105,850
	6724 Alexander Bell Drive	Owned	Howard Co. Perimeter	MD		M		28,312
63	14502 Greenview Drive	Owned	Laurel	MD	1988	M	71,873
64	14504 Greenview Drive	Owned	Laurel	MD	1985	M	69,194
	4260 Forbes Boulevard	JV	Lanham	MD		S		54,692
65	6009 - 6011 Oxon Hill Road	Owned	Southern Prince George's County	MD	1990	M	181,768

	Total Baltimore / Washington Corridor:						4,768,870	580,711

	Greater Philadelphia
1	753 Jolly Road	Owned	Blue Bell	PA	1960/1992 - 94	M	419,472
2	785 Jolly Road	Owned	Blue Bell	PA	1970/1996	M	219,065
3	760 Jolly Road	Owned	Blue Bell	PA	1974/1994	M	208,854
4	751 Jolly Road	Owned	Blue Bell	PA	1966/1991	M	112,958

	Total Greater Philadelphia:						960,349	—

Property Summary by Region—March 31, 2002 (Continued)

Operating Property Count		Owned or Joint Venture (JV)	Submarket	State	Year Built or Renovated	Single Story (S) or Multi-story (M)	Total Operational Square Feet	Total Square Feet Under Development
	Greater Harrisburg
1	2605 Interstate Drive	Owned	East Shore	PA	1990	M	81,187
2	6345 Flank Drive	Owned	East Shore	PA	1989	S	69,443
3	6340 Flank Drive	Owned	East Shore	PA	1988	S	68,200
4	2601 Market Place	Owned	East Shore	PA	1989	M	67,743
5	6400 Flank Drive	Owned	East Shore	PA	1992	S	52,439
6	6360 Flank Drive	Owned	East Shore	PA	1988	S	46,500
7	6385 Flank Drive	Owned	East Shore	PA	1995	S	32,800
8	6380 Flank Drive	Owned	East Shore	PA	1991	S	32,000
9	6405 Flank Drive	Owned	East Shore	PA	1991	S	32,000
10	95 Shannon Road	Owned	East Shore	PA	1999	S	21,976
11	75 Shannon Road	Owned	East Shore	PA	1999	S	20,887
12	6375 Flank Drive	Owned	East Shore	PA	2000	S	19,783
13	85 Shannon Road	Owned	East Shore	PA	1999	S	12,863
14	5035 Ritter Road	Owned	West Shore	PA	1988	S	56,556
15	5070 Ritter Road—Building A	Owned	West Shore	PA	1989	S	32,309
16	5070 Ritter Road—Building B	Owned	West Shore	PA	1989	S	28,000

	Total Greater Harrisburg:						674,686	—

	Northern/Central New Jersey
1	431 Ridge Road	Owned	Exit 8A—Cranbury	NJ	1958/1998	S	170,000
2	429 Ridge Road	Owned	Exit 8A—Cranbury	NJ	1966/1996	M	142,385
3	68 Culver Road	Owned	Exit 8A—Cranbury	NJ	2000	M	57,280
4	104 Interchange Plaza	Owned	Exit 8A—Cranbury	NJ	1990	M	47,677
5	101 Interchange Plaza	Owned	Exit 8A—Cranbury	NJ	1985	M	43,621
6	47 Commerce	Owned	Exit 8A—Cranbury	NJ	1992/1998	S	41,398
7	437 Ridge Road	Owned	Exit 8A—Cranbury	NJ	1962/1996	S	30,000
8	7 Centre Drive	Owned	Exit 8A—Cranbury	NJ	1989	S	19,466
9	8 Centre Drive	Owned	Exit 8A—Cranbury	NJ	1986	S	16,199
10	2 Centre Drive	Owned	Exit 8A—Cranbury	NJ	1989	S	16,132
11	4301 Route 1	Owned	Monmouth Junction	NJ	1986	M	61,300
12	695 Route 46	Owned	Wayne	NJ	1990	M	157,394
13	710 Route 46	Owned	Wayne	NJ	1985	M	101,120

	Total Northern / Central New Jersey:						903,972	—

	Northern Virginia
1	15000 Conference Center Drive	Owned	Chantilly	VA	1989	M	470,406

	Total Northern Virginia:						470,406	—

99	TOTAL PORTFOLIO						7,778,283	580,711

Property Occupancy Rates by Region by Quarter

	Greater Philadelphia		Baltimore / Washington Corridor		Northern / Central New Jersey		Greater Harrisburg		Northern Virginia		Total Portfolio
*March 31, 2002*
Number of Buildings	4		65		13		16		1		99
Rentable Square Feet	960,349		4,768,870		903,972		674,686		470,406		7,778,283
Percent Occupied	100.00	%	92.73	%	93.88	%	89.83	%	99.56	%	93.92	%
*December 31, 2001*
Number of Buildings	4		64		13		16		1		98
Rentable Square Feet	960,349		4,791,139		903,972		674,686		470,406		7,800,552
Percent Occupied	100.00	%	95.68	%	95.80	%	91.17	%	99.56	%	96.07	%
*September 30, 2001*
Number of Buildings	4		64		13		16		—		97
Rentable Square Feet	960,349		4,759,623		904,854		677,903		—		7,302,729
Percent Occupied	100.00	%	98.33	%	95.65	%	87.19	%	0	%	97.18	%
*June 30, 2001*
Number of Buildings	4		58		13		16		—		91
Rentable Square Feet	960,349		4,413,104		904,854		677,903		—		6,956,210
Percent Occupied	100.00	%	97.96	%	94.19	%	89.41	%	0	%	96.92	%
*March 31, 2001*
Number of Buildings	4		55		14		16		—		89
Rentable Square Feet	960,349		4,258,610		970,048		677,458		—		6,866,465
Percent Occupied	100.00	%	97.76	%	94.03	%	91.75	%	0	%	96.95	%

Top Twenty Office Tenants as of March 31, 2002

(Dollars and Square Feet in thousands)

Tenant	Number of Leases	Total Occupied Square Feet	Percentage of Total Occupied Square Feet		Total Rental Revenue⁽¹⁾		Percentage of Total Rental Revenue		Weighted Average Remaining Lease Term⁽²⁾
United States of America⁽³⁾	21	896,012	12.3	%	$	16,663	12.8	%	4.2
AT&T Local Services⁽⁴⁾	6	414,970	5.7	%		8,628	6.6	%	6.5
Unisys⁽⁵⁾	3	741,284	10.1	%		7,444	5.7	%	7.3
Dyncorp Information Systems, LLC	1	244,522	3.3	%		5,384	4.1	%	8.8
Ciena Corporation⁽⁶⁾	5	298,482	4.1	%		3,968	3.0	%	3.2
General Dynamics Government Corp.	3	161,657	2.2	%		3,798	2.9	%	7.1
Magellan Behavioral Health, Inc.	2	150,622	2.1	%		3,259	2.5	%	1.8
Commonwealth of Pennsylvania⁽⁴⁾	9	177,813	2.4	%		2,533	1.9	%	6.5
Booz-Allen & Hamilton	3	127,919	1.8	%		2,527	1.9	%	3.3
Merck & Co., Inc.⁽⁵⁾	1	219,065	3.0	%		2,237	1.7	%	7.3
Bookham Technology, Inc.	1	150,000	2.1	%		1,900	1.5	%	5.8
Johns Hopkins University⁽⁴⁾	4	81,935	1.1	%		1,836	1.4	%	4.4
Northrop Grumman Systems	1	61,250	0.8	%		1,554	1.2	%	6.5
Arbros Communications, Inc.	1	91,534	1.3	%		1,554	1.2	%	9.1
Genuity, Inc.	1	59,173	0.8	%		1,538	1.2	%	2.2
Sun Microsystems, Inc.	2	60,730	0.8	%		1,484	1.1	%	3.8
First American Credit Management Solutions, Inc.	1	70,982	1.0	%		1,374	1.1	%	6.7
Deutsche Banc Alex. Brown	1	84,354	1.2	%		1,327	1.0	%	2.2
Ameritrade Holding Corporation	1	63,224	0.9	%		1,293	1.0	%	8.3
Computer Sciences Corporation	1	55,232	0.8	%		1,207	0.9	%	0.2
Subtotal Top 20 Office Tenants	68	4,210,760	57.6	%		71,508	54.7	%	5.4
All remaining tenants	369	3,094,573	42.4	%		59,132	45.3	%	3.1

Total/Weighted Average	437	7,305,333	100.0	%	$	130,640	100.0	%	4.4

(1): Total Rental Revenue is the monthly contractual base rent as of March 31, 2002 multiplied by 12 plus the estimated annualized expense reimbursements under existing office leases.
(2): The weighting of the lease term was computed using Total Rental Revenue.
(3): Many of our government leases are subject to early termination provisions which are customary to government leases. The weighted average remaining lease term was computed assuming no exercise of such early termination rights.
(4): Includes affiliated organizations or agencies.
(5): Merck & Co., Inc. subleases 219,065 rentable square feet from Unisys' 960,349 leased rentable square feet.
(6): In addition to the 298,482 square feet directly leased, Ciena Corporation also subleases 107,064 rentable square feet from various tenants in our portfolio over different lease terms.

Total Rental Revenue by Geographic Region by Quarter⁽¹⁾

(Dollars in thousands)

	2002		2001
	March 31		December 31		September 30		June 30		March 31
Office Properties:
Greater Philadelphia	$	2,506	$	2,506	$	2,506	$	2,506	$	2,506
Baltimore/Washington Corridor		21,896		22,911		22,558		18,654		18,573
Northern/Central New Jersey		4,921		4,786		4,757		4,998		4,922
Greater Harrisburg		2,407		2,231		2,174		2,483		2,789
Northern Virginia		2,688		947		—		—		—

Total Regional Rental Revenue	$	34,418	$	33,381	$	31,995	$	28,641	$	28,790

(1): Rental revenue represents GAAP revenue including operating expense reimbursements, straight line rent adjustments and tenant services income.

Net Operating Income by Geographic Region by Quarter

(Dollars in thousands)

		2002		2001
		March 31		December 31		September 30		June 30		March 31
Office Properties:
Greater Philadelphia		$	2,466	$	2,478	$	2,476	$	2,469	$	2,486
Baltimore/Washington Corridor			15,140		15,745		15,539		12,704		12,614
Northern/Central New Jersey			3,213		2,890		2,819		3,173		3,028
Greater Harrisburg			1,810		1,640		1,506		1,736		2,195
Northern Virginia			1,598		527		—		—		—

Total Regional NOI		$	24,227	$	23,280	$	22,340	$	20,082	$	20,323
Other income / expenses, net			79		78		54		71		62

	Total NOI	$	24,306	$	23,358	$	22,394	$	20,153	$	20,385

Same Office Property Cash Net Operating Income by Quarter⁽¹⁾

(Dollars in thousands)

		2002		2001
		March 31		December 31		September 30		June 30		March 31
Office Properties:⁽²⁾
Greater Philadelphia		$	2,410	$	2,410	$	2,408	$	2,363	$	2,363
Baltimore/Washington Corridor			12,078		11,720		12,316		11,988		11,977
Northern/Central New Jersey			3,221		2,850		2,779		2,845		2,665
Greater Harrisburg			1,773		1,645		1,489		1,707		1,718

	Total Office Properties	$	19,482	$	18,625	$	18,992	$	18,903	$	18,723

Same Office Property GAAP Net Operating Income by Quarter⁽¹⁾

(Dollars in thousands)

		2002		2001
		March 31		December 31		September 30		June 30		March 31
Office Properties:⁽²⁾
Greater Philadelphia		$	2,496	$	2,496	$	2,495	$	2,497	$	2,497
Baltimore/Washington Corridor			12,113		11,906		12,683		12,384		12,361
Northern/Central New Jersey			3,265		2,922		2,854		2,940		2,756
Greater Harrisburg			1,834		1,654		1,518		1,757		1,753

	Total Office Properties	$	19,708	$	18,978	$	19,550	$	19,578	$	19,367

(1): Net operating income for same office properties has been presented on a GAAP basis and a modified cash basis which removes the effect of straight-line rents from the GAAP net operating income.
(2): Same office properties include buildings owned for a minimum of five reporting quarters.

Average Occupancy Rates by Region for Same Office Properties⁽¹⁾

	Greater Philadelphia		Baltimore / Washington Corridor		Northern / Central New Jersey		Greater Harrisburg		Total Office
*1st Quarter 2002 Average*
Number of Buildings	4		49		13		16		82
Rentable Square Feet	960,349		3,867,273		903,972		674,686		6,406,280
Percent Occupied	100.00	%	94.03	%	94.46	%	90.48	%	94.61	%
*4th Quarter 2001 Average*
Number of Buildings	4		49		13		16		82
Rentable Square Feet	960,349		3,866,633		903,972		675,758		6,406,712
Percent Occupied	100.00	%	95.76	%	95.82	%	89.03	%	95.70	%
*3rd Quarter 2001 Average*
Number of Buildings	4		49		13		16		82
Rentable Square Feet	960,349		3,865,971		904,854		677,903		6,409,077
Percent Occupied	100.00	%	98.65	%	95.19	%	87.01	%	97.13	%
*2nd Quarter 2001 Average*
Number of Buildings	4		49		13		16		82
Rentable Square Feet	960,349		3,848,223		904,834		677,606		6,391,012
Percent Occupied	100.00	%	98.29	%	94.22	%	90.24	%	97.11	%
*1st Quarter 2001 Average*
Number of Buildings	4		49		13		16		82
Rentable Square Feet	960,349		3,839,288		904,771		677,461		6,381,869
Percent Occupied	100.00	%	97.59	%	92.19	%	93.32	%	96.74	%

(1): Same office properties include buildings owned for a minimum of five reporting quarters.

Office Lease Expiration Analysis by Year

Year of Lease Expiration⁽¹⁾	Number of Leases Expiring	Square Footage of Leases Expiring	Percentage of Total Occupied Square Feet		Total Rental Revenue of Expiring Leases⁽²⁾		Percentage of Total Rental Revenue Expiring		Total Rental Revenue of Expiring Leases per Occupied Square Foot
					($000s)
April 1 - December 31, 2002	80	853,226	11.7	%	$	15,448	11.8	%	$	18.11
2003	91	747,770	10.2	%		14,103	10.8	%		18.86
2004	72	826,766	11.3	%		16,813	12.7	%		20.34
2005	65	692,563	9.5	%		14,504	11.1	%		20.94
2006	52	607,542	8.3	%		11,930	9.1	%		19.64
2007	27	623,347	8.5	%		10,331	7.9	%		16.57
2008	13	782,006	10.7	%		15,019	11.5	%		19.21
2009	14	1,230,442	16.8	%		14,906	11.4	%		12.11
2010	11	657,393	9.0	%		14,019	10.8	%		21.33
2011	4	165,443	2.3	%		2,314	1.8	%		13.99
2012	1	71,514	1.0	%		1,251	1.0	%		17.50
Other⁽³⁾	7	47,321	0.6	%		—	0.0	%		—

Total/Weighted Average	437	7,305,333	100.0	%	$	130,640	100.0	%	$	18.52

NOTE: As of March 31, 2002, the weighted average lease term is 4.4 years.

(1): Many of our government leases are subject to certain early termination provisions which are customary to government leases. The year of lease expiration was computed assuming no exercise of such early termination rights.
(2): Total Rental Revenue is the monthly contractual base rent as of March 31, 2002 multiplied by 12 plus the estimated annualized expense reimbursements under existing office leases.
(3): Other consists primarily of amenities, including cafeterias, concierge offices and property management space.

Quarterly Office Renewal Analysis

		Greater Philadelphia			Baltimore/ Washington Corridor			Northern/ Central New Jersey			Greater Harrisburg			Total Office
Quarter Ended March 31, 2002:
	Expiring Square Feet		—			42,032			11,961			53,200			107,193
	Vacated Square Feet		—			21,125			9,992			15,280			46,397
	Renewed Square Feet		—			20,907			1,969			37,920			60,796
	Retention Rate (% based upon square feet)		0.00	%		49.74	%		16.46	%		71.28	%		56.72	%
Renewal & Retenanted Space:
	Increase in Base Rent—Straight-line		0.00	%		(4.35	)%		(2.70	)%		29.35	%		3.21	%
	Increase in Total Rent—Straight-line		0.00	%		0.55	%		(12.76	)%		(2.02	)%		(1.53	)%
	Increase in Base Rent—Cash		0.00	%		(3.11	)%		(7.51	)%		20.16	%		1.71	%
	Increase in Total Rent—Cash		0.00	%		2.04	%		(16.86	)%		(9.06	)%		(3.05	)%
	Average Capital Cost per Square Foot	$	—		$	5.01		$	5.67		$	0.04		$	3.08
Quarter Ended December 31, 2001:
	Expiring Square Feet		—			84,400			4,276			53,256			141,932
	Vacated Square Feet		—			24,674			—			5,005			29,679
	Renewed Square Feet		—			59,726			4,276			48,251			112,253
	Retention Rate (% based upon square feet)		0.00	%		70.77	%		100.00	%		90.60	%		79.09	%
Renewal & Retenanted Space:
	Increase in Base Rent—Straight-line		0.00	%		12.52	%		17.24	%		18.61	%		15.16	%
	Increase in Total Rent—Straight-line		0.00	%		9.42	%		6.74	%		17.70	%		12.58	%
	Increase in Base Rent—Cash		0.00	%		5.95	%		11.02	%		5.78	%		6.08	%
	Increase in Total Rent—Cash		0.00	%		3.10	%		1.07	%		5.08	%		3.80	%
	Average Capital Cost per Square Foot	$	—		$	9.56		$	8.92		$	15.25		$	12.20
Quarter Ended September 30, 2001:
	Expiring Square Feet		—			182,914			7,777			97,943			288,634
	Vacated Square Feet		—			122,030			—			—			122,030
	Renewed Square Feet		—			60,884			7,777			97,943			166,604
	Retention Rate (% based upon square feet)		0.00	%		33.29	%		100.00	%		100.00	%		57.72	%
Renewal & Retenanted Space:
	Increase in Base Rent—Straight-line		0.00	%		13.01	%		25.29	%		8.18	%		11.93	%
	Increase in Total Rent—Straight-line		0.00	%		10.17	%		15.05	%		6.47	%		9.07	%
	Increase in Base Rent—Cash		0.00	%		8.22	%		18.70	%		5.90	%		7.87	%
	Increase in Total Rent—Cash		0.00	%		5.76	%		9.46	%		4.64	%		5.51	%
	Average Capital Cost per Square Foot	$	—		$	7.34		$	5.67		$	0.95		$	4.40

Quarterly Office Renewal Analysis (Continued)

		Greater Philadelphia			Baltimore/ Washington Corridor			Northern/ Central New Jersey			Greater Harrisburg			Total Office
Quarter Ended June 30, 2001:
	Expiring Square Feet		—			174,078			22,678			45,325			242,081
	Vacated Square Feet		—			16,922			6,050			33,026			55,998
	Renewed Square Feet		—			157,156			16,628			12,299			186,083
	Retention Rate (% based upon square feet)		0.00	%		90.28	%		73.32	%		27.14	%		76.87	%
Renewal & Retenanted Space:
	Increase in Base Rent—Straight-line		0.00	%		24.86	%		38.02	%		13.69	%		26.15	%
	Increase in Total Rent—Straight-line		0.00	%		19.76	%		32.98	%		10.21	%		21.02	%
	Increase in Base Rent—Cash		0.00	%		19.81	%		34.23	%		4.57	%		21.00	%
	Increase in Total Rent—Cash		0.00	%		15.52	%		29.50	%		2.37	%		16.63	%
	Average Capital Cost per Square Foot	$	—		$	3.87		$	14.05		$	6.50		$	5.58
Quarter Ended March 31, 2001:
	Expiring Square Feet		—			80,677			1,510			4,000			86,187
	Vacated Square Feet		—			1,215			—			—			1,215
	Renewed Square Feet		—			79,462			1,510			4,000			84,972
	Retention Rate (% based upon square feet)		0.00	%		98.49	%		100.00	%		100.00	%		98.59	%
Renewal & Retenanted Space:
	Increase in Base Rent—Straight-line		0.00	%		23.01	%		2.78	%		(28.63	)%		20.44	%
	Increase in Total Rent—Straight-line		0.00	%		20.31	%		2.03	%		(18.63	)%		18.20	%
	Increase in Base Rent—Cash		0.00	%		15.15	%		2.78	%		(30.74	)%		12.95	%
	Increase in Total Rent—Cash		0.00	%		12.84	%		2.03	%		(20.55	)%		11.12	%
	Average Capital Cost per Square Foot	$	—		$	7.20		$	0.42		$	1.70		$	6.88

Development Summary as of March 31, 2002

(Dollars in thousands except square feet and per square foot data)

Property and Location		Submarket	Owned or Joint Venture (JV)	Rentable Square Feet	Percentage Pre-Leased or Committed		Anticipated Cost per Rentable Square Foot		Anticipated Cost		Cost to date		Loan Commitment		Outstanding Loan as of 3/31/2002		Anticipated Stabilization/ Delivery
*Under Construction*
	2711 Technology Drive (211 NBP) Annapolis Junction, MD	BWI Airport	JV	150,000	100.00	%	$	175	$	26,215	$	22,806	$	20,550	$	13,430	June 2002
	1304 Concourse Drive Linthicum, MD⁽¹⁾	BWI Airport	Owned	92,307	58.60	%		162		14,964		11,830		11,855		7,045	Lease-up September 2002
	4260 Forbes Boulevard—Phase I Lanham, Maryland⁽²⁾	Lanham	JV	54,692	43.08	%		100		5,494		4,801		9,026		4,789	Lease-up October 2002
	6724 Alexander Bell Drive⁽³⁾ Columbia, Maryland	Howard County Perimeter	Owned	28,312	62.18	%		181		5,119		4,849		—		—	Lease-up November 2002
	6731 Columbia Gateway Drive Columbia, Maryland	Howard County Perimeter	Owned	123,743	57.57	%		190		23,511		18,976		15,750		10,489	Lease-up February 2003
	Robert Fulton Drive—Phase I Columbia, Maryland⁽²⁾	Howard County Perimeter	JV	105,850	0.00	%		115		12,185		8,832		14,000		6,508	March 2003

	TOTAL / AVERAGE			554,904	57.04	%	$	158	$	87,488	$	72,094	$	71,181	$	42,261

(1): This property contains 102,964 rentable square feet of which 10,657 rentable square feet have been placed into service in March 2002. Accordingly, the anticipated cost and cost to date have been adjusted to reflect only the developmental portion of the property.
(2): The loan commitments and outstanding loan balances as of March 31, 2002 for these joint venture properties cover Phase I and Phase II development activities.
(3): We purchased this property in May 2001 and are redeveloping. As part of a $12 million loan, we can borrow an additional $1.0 million to fund construction costs. No draws have been made as of March 31, 2002.

Joint Venture Summary as of March 31, 2002

(Dollars in thousands except acreage and square feet)

Property and Location		Joint Venture Interest Held By COPT	Status	Square Feet	Acreage	COPT Investment			Off-Balance Sheet Debt as of 3/31/02		Recourse to COPT		Option to Acquire Partner's Interest
4260 Forbes Boulevard Lanham, Maryland		80%	Lease-Up	54,692		$	921		$	4,789	Yes, 50	%	Yes
2711 Technology Drive (211 NBP) Annapolis Junction, Maryland		50%	Construction	150,000			3,224	^(a)		13,430	Yes, 100	%	Yes
Robert Fulton Drive (Phase I) Columbia, Maryland		80%	Construction/ Development	105,850	4 acres		3,972			6,508	Yes, 80	%	Yes
MOR Montpelier 3 LLC Laurel, Maryland		50%	Development		2 acres		298	^(b)		270	No		Yes
Gateway 70 Columbia, Maryland		80%	Development		12 acres		2,366			—	N/A		Yes
140 NBP Annapolis Junction, Maryland		20%	Development		8 acres		3,182			—	N/A		No

	TOTAL					$	13,963		$	24,997

(a): Upon formation of this joint venture, we contributed land and have recorded our investment as land, construction in progress and buildings and improvements on our balance sheet. In addition, we obtained an option to acquire the joint venture partner's interest for a pre-determined price. Accordingly, we recorded a liability and are accreting towards the pre-determined purchase price over the respective time period. Refer to our most recent Form 10-Q for additional disclosure.
(b): On February 21, 2002, we contributed $292,000 to a joint venture for this development opportunity.

QuickLinks

Corporate Office Properties Trust Index to Supplemental Information (Unaudited) March 31, 2002
Quarterly Selected Financial Summary Data (Dollars in thousands)
Quarterly Consolidated Balance Sheets (Dollars in thousands except per share data)
Quarterly Consolidated Statements of Operations and Funds From Operations (FFO) (Dollars and units in thousands)
Quarterly Consolidated Statements of Operations and FFO per Diluted Share (Shares in thousands)
Quarterly Consolidated Statements of Operations and FFO as a Percentage of Total Revenues
Quarterly Equity Analysis (Amounts in thousands, except per share data, share prices and ratios)
Quarterly Valuation Analysis (Dollars in thousands except per share data and ratios)
Quarterly Debt Analysis (Dollars in thousands)
Quarterly Operating Ratios (Dollars in thousands except per share data and ratios)
Investor Composition and Analyst Coverage (as of March 31, 2002)
Debt Maturity Schedule—March 31, 2002 (Dollars in thousands)
Property Summary by Region—March 31, 2002
Property Summary by Region—March 31, 2002 (Continued)
Property Summary by Region—March 31, 2002 (Continued)
Property Occupancy Rates by Region by Quarter
Top Twenty Office Tenants as of March 31, 2002 (Dollars and Square Feet in thousands)
Total Rental Revenue by Geographic Region by Quarter⁽¹⁾ (Dollars in thousands)
Net Operating Income by Geographic Region by Quarter (Dollars in thousands)
Same Office Property Cash Net Operating Income by Quarter⁽¹⁾ (Dollars in thousands)
Same Office Property GAAP Net Operating Income by Quarter⁽¹⁾ (Dollars in thousands)
Average Occupancy Rates by Region for Same Office Properties⁽¹⁾
Office Lease Expiration Analysis by Year
Quarterly Office Renewal Analysis
Quarterly Office Renewal Analysis (Continued)
Development Summary as of March 31, 2002 (Dollars in thousands except square feet and per square foot data)
Joint Venture Summary as of March 31, 2002 (Dollars in thousands except acreage and square feet)