Today at 3:30pm Fairfax County’s planning staff recommends allowing Boston Properties to replace garage parking, retail, and restaurant space with office space in the next block of the massive Reston Gateway mixed-use development. In a report released last week, the staff says they support amending the plans to permit an office building in Block D of the development. The report states that this would “maximize” unused office space and place offices closer to the impending Reston Town Center Metro station, putting them about a quarter mile from the entrance. The proposed office building could go as high up as 44 stories. The county has already approved plans for two residential towers — potentially 12 and 36 stories tall — with below-grade parking.