| **Exhibit 12.1**                                                                                                            |
|-----------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                        |
|  **Brandywine Operating Partnership, L.P.  Computation of Ratio of Earnings to Combined Fixed Charges (in thousands)** |

|                                                                             |   |                              |    |   |                                |   |
|----------------------------------------------------------------------------------|--------|-----------------------------------|---------|--------|-------------------------------------|--------|
|                                                                             |   |                              |    |   | For the years ended    December 31, |   |
|                                                                             |   | For the six months ended June 30, |    |        |                                |
|                                                                             |   | 2006                              |    | 2005   |                                | 2005   |   | 2004 |   | 2003 |   | 2002 |   | 2001 |   |
|                                                                             |   |                                   |         |   |                                     |        |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |
| **Earnings before fixed charges:**                                               |   |                              |    |   |                                |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Add:**                                                                         |   |                              |    |   |                                |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Income    (loss) from continuing operations                                      |   | $                                 | (18,278 | )      | $                                   | 19,016 |   | $ | 41,976 |   | $ | 60,281 |   | $ | 85,126 |   | $ | 57,018 |   | $ | 27,222 |   |
| Minority    interest – partners' share of consolidated real estate ventures |   |                              | (370    | )      |                                | 172    |   |   | 154 |   |   | (205 | ) |   | — |   |   | — |   |   | — |   |
| Fixed    charges – per below                                                |   |                              | 90,924  |   |                                | 40,782 |   |   | 86,636 |   |   | 61,062 |   |   | 62,407 |   |   | 69,881 |   |   | 76,558 |   |
| **Less:**                                                                        |   |                              |    |   |                                |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Capitalized    interest                                                          |   |                              | (4,916  | )      |                                | (3,870 | ) |   | (9,603 | ) |   | (3,030 | ) |   | (1,503 | ) |   | (2,949 | ) |   | (5,178 | ) |
|                                                                             |   |                                   |         |   |                                     |        |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |
| Earnings before fixed charges                                                    |   | $                                 | 67,360  |   | $                                   | 56,100 |   | $ | 119,163 |   | $ | 118,108 |   | $ | 146,030 |   | $ | 123,950 |   | $ | 98,602 |   |
|                                                                             |   |                                   |         |   |                                     |        |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |
| **Fixed charges:**                                                               |   |                              |    |   |                                |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Interest expense (including amortization)                                        |   | $                                 | 83,467  |   | $                                   | 35,604 |   | $ | 74,363 |   | $ | 55,061 |   | $ | 57,835 |   | $ | 63,522 |   | $ | 67,496 |   |
| Capitalized interest                                                             |   |                              | 4,916   |   |                                | 3,870  |   |   | 9,603 |   |   | 3,030 |   |   | 1,503 |   |   | 2,949 |   |   | 5,178 |   |
| Proportionate    share of interest for unconsolidated real estate ventures       |   |                              | 2,541   |   |                                | 1,308  |   |   | 2,670 |   |   | 2,971 |   |   | 3,069 |   |   | 3,410 |   |   | 3,884 |   |
|                                                                             |   |                                   |         |   |                                     |        |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |
| Total    Fixed Charges                                                           |   |                              | 90,924  |   |                                | 40,782 |   |   | 86,636 |   |   | 61,062 |   |   | 62,407 |   |   | 69,881 |   |   | 76,558 |   |
|                                                                             |   |                              |    |   |                                |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Ratio of earnings to combined fixed charges                                      |   |                              | 0.74    |   |                                | 1.38   |   |   | 1.38 |   |   | 1.93 |   |   | 2.34 |   |   | 1.77 |   |   | 1.29 |   |
|                                                                             |   |                                   |         |   |                                     |        |   |  |  |   |  |  |   |  |  |   |  |  |   |  |  |   |

|      |                                                                                                                                                                                                                                                                                                                                                                                                                              |
|-----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|  (a) | Amounts    for the six months ended June 30, 2006 and 2005 and for the years ended December    31, 2005, 2004, 2003, 2002 and 2001 have been reclassified to present properties    sold or identified as held for sale consistent with the presentation for    the period ended June 30, 2006. As a result, operations have been reclassified    to discontinued operations from continuing operations for all periods presented. |

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