CONTACT:

William T. Camp

Executive Vice President and

6110 Executive Blvd., Suite 800

Rockville, Maryland 20852

Tel 301-984-9400

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Net income was $0.20 per diluted share compared to $(0.06) per diluted share in the same period one year ago. Included in the first quarter 2009 and first quarter 2008 net income are respective charges of $0.05 and $0.03 per diluted share from the adoption of an accounting pronouncement impacting the accounting of our 3.875% convertible notes⁽¹⁾. Also included in the first quarter 2009 net income is a gain of $0.11 per diluted share related to the repurchase of convertible debt. Also included in the first quarter 2008 net income is a $0.18 per diluted share non-recurring charge for the extinguishment of $60 million of 10-year Mandatory Par Put Remarketed Securities (“MOPPRS”).

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Funds From Operations (FFO)⁽³⁾ was $0.65 per diluted share compared to $0.38 per diluted share in the same period one year ago. Included in the first quarter 2009 and first quarter 2008 FFO are respective charges of $0.05 and $0.03 per diluted share from the adoption of an accounting pronouncement impacting the accounting of our 3.875% convertible notes⁽¹⁾ . Also included in the first quarter 2009 FFO is a gain of $0.11 per diluted share related to the repurchase of convertible debt. Also included in the first quarter 2008 FFO is a $0.18 per diluted share non-recurring charge for the extinguishment of $60 million of 10-year Mandatory Par Put Remarketed Securities (“MOPPRS”).

Guidance for 2009 FFO per diluted share remains unchanged.

Multifamily properties’ core NOI for the first quarter increased 3.1% compared to the same period one year ago. Rental rate growth was 2.2% while core economic occupancy decreased 120 bps to 91.6%. Sequentially, core economic occupancy decreased from 92.8% in the fourth quarter of 2008.

Medical office properties’ core NOI for the first quarter increased 3.6% compared to the same period one year ago. Rental rate growth was 2.5% while core economic occupancy decreased 80 bps to 97.1%. Sequentially, core economic occupancy increased from 95.2% in the fourth quarter of 2008.

Office properties’ core NOI for the first quarter decreased 6.1% compared to the same period one year ago, primarily due to increased bad debt expense. Rental rate growth was 2.9% while core economic occupancy decreased 330 bps to 92.2%, primarily due to occupancy reduction at the One Central Plaza office building. Sequentially, core economic occupancy declined from 93.2% in the fourth quarter of 2008.

Retail properties’ core NOI for the first quarter decreased 8.0% compared to the same period one year ago, primarily due to increased bad debt expense and higher operating expenses throughout the portfolio. Rental rate growth was 3.0% while core economic occupancy decreased 10 bps to 95.2%. Sequentially, core economic occupancy increased from 94.8% in the fourth quarter of 2008.

Industrial properties’ core NOI for the first quarter decreased 7.8% compared to the same period one year ago, primarily due to lower occupancy at Northern Virginia Industrial Park and higher operating expenses throughout the portfolio. Rental rate growth was 1.0% while core economic occupancy decreased 440 bps to 90.3%. Sequentially, core economic occupancy declined from 92.4% in the fourth quarter of 2008.

Rental rates for new and renewed medical office leases increased 9.8% to $35.08 per square foot, with $8.12 per square foot in tenant improvement costs and $2.05 per square foot in leasing costs.

Rental rates for new and renewed office leases increased 13.4% to $31.84 per square foot, with $16.03 per square foot in tenant improvement costs and $12.36 per square foot in leasing costs.

Rental rates for new and renewed retail leases decreased 5.2% to $17.52 per square foot, with $0.26 per square foot in tenant improvement costs and $3.48 per square foot in leasing costs.

Rental rates for new and renewed industrial/flex leases increased 13.4% to $9.82 per square foot, with $0.17 per square foot in tenant improvement costs and $0.57 per square foot in leasing costs.

⁽¹⁾

(1) Financial Accounting Standards Board Staff Position APB14-1, Accounting for Convertible Debt Instruments That May Be Settled in Cash upon Conversion (Including Partial Cash Settlement) (“FSP 14-1”), requires the bifurcation of a component of our 3.875% convertible notes, classification of that component in shareholders’ equity, and accretion of the resulting discount on the convertible notes to interest expense. As a result of the adoption of FSP 14-1, equity increased by $21.0 million as of March 31, 2009 and December 31, 2008. The principal balance of our 3.875% convertible notes was reduced by $8.7 million and $11.9 million as of March 31, 2009 and December 31, 2008, respectively, and the unamortized balance of the related loan origination costs was reduced by $2.2 million and 2.7 million, respectively. The decline in principal reflects the unamortized discount balance related to the adoption of FSP 14-1. Interest expense increased $1.2 million in the first quarters of both 2009 and 2008 as a result of the adoption. The gain on extinguishment of debt decreased by $1.5 million for the first quarter of 2009 as a result of the adoption.

⁽²⁾

As of the first quarter of 2009, we adopted SFAS No. 160, Noncontrolling Interests in Consolidated Financial Statements (“FAS 160”), under which noncontrolling interests of consolidated partnerships (previously referred to as “minority interests”) are reported as a component of equity. Under FAS 160, net income encompasses the total income of all consolidated subsidiaries and there is a separate disclosure on the face of the consolidated statement of income of the attribution of that income between controlling and noncontrolling interests. The implementation of this standard had no effect on our basic or diluted earnings per share calculation.

⁽³⁾

Funds From Operations (“FFO”) – The National Association of Real Estate Investment Trusts, Inc. (“NAREIT”) defines FFO (April, 2002 White Paper) as net income (computed in accordance with generally accepted accounting principles (“GAAP”)) excluding gains (or losses) from sales of property plus real estate depreciation and amortization. FFO is a non-GAAP measure and does not replace net income as a measure of performance or net cash provided by operating activities as a measure of liquidity. We consider FFO to be a standard supplemental measure for equity real estate investment trusts (“REITs”) because it facilitates an understanding of the operating performance of our properties without giving effect to real estate depreciation and amortization, which historically assumes that the value of real estate assets diminishes predictably over time. Since real estate values have instead historically risen or fallen with market conditions, we believe that FFO more accurately provides investors an indication of our ability to incur and service debt, make capital expenditures and fund other needs.

⁽⁴⁾

Funds Available for Distribution (“FAD”) is a non-GAAP measure. It is calculated by subtracting from FFO (1) recurring expenditures, tenant improvements and leasing costs that are capitalized and amortized and are necessary to maintain our properties and revenue stream and (2) straight-line rents, then adding (3) non-real estate depreciation and amortization, (4) amortization of restricted share and unit compensation, and adding or subtracting amortization of lease intangibles, as appropriate. We consider FAD to be a measure of a REIT’s ability to incur and service debt and to distribute dividends to its shareholders. FAD is a non-standardized measure and may be calculated differently by other REITs.

⁽⁵⁾

Net Operating Income (“NOI”), defined as real estate rental revenue less real estate expenses, is a non-GAAP measure. We provide NOI as a supplement to net income calculated in accordance with GAAP. As such, it should not be considered an alternative to net income as an indication of our operating performance. It is the primary performance measure we use to assess the results of our operations at the property level. NOI is calculated as net income, less non-real estate revenue and the results of discontinued operations (including the gain on sale, if any), plus interest expense, depreciation and amortization and general and administrative expenses.

⁽⁶⁾

For purposes of evaluating comparative operating performance, we categorize our properties as “core” or “non-core”. A core property is one that was owned for the entirety of the periods being evaluated. A non-core property is one that was acquired or placed into service during either of the periods being evaluated.

Residential

Office

Medical Office

Retail

Industrial

Overall Portfolio

⁽ⁱ⁾

Core properties include all properties that were owned for the entirety of the current and prior year reporting periods. For Q1 2009 and Q1 2008, core properties exclude:

⁽ⁱⁱ⁾

Residential occupancy for all properties reflects the completion of Bennett Park and Clayborne Apartments. At 3/31/09, 174 of 224 units were occupied at Bennett Park and 60 of 74 units were occupied at Clayborne Apartments.

OPERATING RESULTS

Revenue

Real estate rental revenue

Expenses

Real estate expenses

Depreciation and amortization

General and administrative

Real estate operating income

Other income/(expense):

Interest expense⁽¹⁾

Gain (loss) on extinguishment of debt

Other income

Income from continuing operations

Discontinued operations:

Income from operations of properties held for sale

Net income

Less: Net income attributable to noncontrolling interests⁽²⁾

Net income attributable to the controlling interests⁽²⁾

Income from continuing operations attributable to the controlling interests

Continuing operations real estate depreciation and amortization

Funds from continuing operations

Income from discontinued operations before gain on sale

Discontinued operations real estate depreciation and amortization

Funds from discontinued operations

Funds from operations⁽²⁾

Gain on extinguishment of debt

Tenant improvements

External and internal leasing commissions capitalized

Recurring capital improvements

Straight-line rents, net

Non-cash fair value interest expense

Non real estate depreciation & amortization of debt costs

Amortization of lease intangibles, net

Amortization and expensing of restricted share and unit compensation

Other

Funds available for distribution⁽³⁾

Per share data attributable to the controlling interests:

Income from continuing operations

Net income

Funds from continuing operations

Funds from operations

Dividends paid

Weighted average shares outstanding

Fully diluted weighted average shares outstanding

Assets

Land

Income producing property

Accumulated depreciation and amortization

Net income producing property

Development in progress

Total real estate held for investment, net

Investment in real estate sold or held for sale

Cash and cash equivalents

Restricted cash

Rents and other receivables, net of allowance for doubtful accounts of $7,489 and $6,278

Prepaid expenses and other assets⁽¹⁾

Other assets related to property sold or held for sale

Total assets

Liabilities

Notes payable

Mortgage notes payable

Lines of credit⁽¹⁾

Accounts payable and other liabilities

Advance rents

Tenant security deposits

Other liabilities related to property sold or held for sale

Total liabilities

Shareholders’ equity

Shares of beneficial interest, $0.01 par value; 100,000 shares authorized; 53,000 and 52,434 shares issued and outstanding, respectively

Additional paid-in capital⁽¹⁾

Distributions in excess of net income

Accumulated other comprehensive income

Total shareholders’ equity

Noncontrolling interests in subsidiaries⁽²⁾

Total equity

Total liabilities and equity

Core net operating income⁽⁶⁾

Add: Net operating income from non-core properties⁽⁶⁾

Total net operating income⁽⁵⁾

Add/(deduct):

Other income

Interest expense

Gain (loss) on extinguishment of debt

Depreciation and amortization expense

General and administrative expenses

Income from operations of properties held for sale

Net income

Less: Net income attributable to the noncontrolling interests

Net income attributable to the controlling interests

Core net operating income⁽⁶⁾

Add: Net operating income from non-core properties⁽⁶⁾

Total net operating income⁽⁵⁾

Add/(deduct):

Other income

Interest expense

Gain (loss) on extinguishment of debt

Depreciation and amortization expense

General and administrative expenses

Income from operations of properties held for sale

Net income

Less: Net income attributable to the noncontrolling interests

Net income attributable to the controlling interests