Approved or under construction:

* Ballston Common: Shopping center and three office buildings of up to 12 stories. Cost: $100 million; developer: May Co.

* Ballston One: 12-story office building. Cost: $20 million; developer: Radnor/Buchanan.

* Ballston Plaza: 17-story office building, 11-story office building and eight-story office building, two residential buildings and 84 town houses. Cost: $175 million; developer: Oliver T. Carr Co.

* 600 N. Glebe Rd.: Two eight-story twin office towers. Cost: $60 million; developer: Washington Corp.

* Arlington Square: Eight-story office building and nine-story condominium. Cost: about $38 million; developer: Washington Corp.

* Ballston Station: Four eight-story office buildings and 248 residential units. Cost: $50 million; developer: Ballston Station Associates.

* Ballston Corporate Center: Two office buildings of up to 10 stories. Cost: $40 million; developer: Evans Co.

* Summerwalk: Eight-story condominium. Cost: $10 million; developer: Ray Simms Co.

* Enterprise Square: Comfort Inn motel and 23 town houses. Cost: $8.2 million; developer: Misner Development Corp.

* Randolph Towers: 21-story apartment building.

* Arlington-Ballston Inn: 227-room Holiday Inn. Planned but not approved:

* Stafford Place at Ballston: Mixed-use site, including four 13-story office buildings and two 22-story residential buildings. Cost: $200 million; developer: Stafford Development Corp.

* Radnor/Buchanan: 800,000-square-foot mixed-use site.

* Ballston Metro Center: 19-story condominium, 13-story office building and eight-story hotel. Cost: $75 million; developer: International Developers Inc.