Hi, Confused. I think most people will agree that a house sitting right next to BART tracks vs. one far away will be less desirable to a future buyer.
However, keep in mind that building a BART station in Warm Springs has a positive effect on house prices for the entire area. As it stands now, the station will be built at the intersection of Warm Springs Rd. and Grimmer, which is approximately 5000 meters north of the Robson (and KB) development. Based on a study from UC Berkeley in 1990, homes in Alameda County located 5000 meters (3 miles) from a BART station sold for $40,000 more (20% at that time) than homes further than 25000 meters (15 miles) away. [see link below, page 22]
This study also looked at differences in home prices for houses located less than 300 meters from BART *TRACKS* vs. greater than 300 meters, also in Alameda County and in 1990. They found no differences, which means that _on_average_, houses located within 300 meters of BART tracks didn't sell for less. In fact, in other California counties, the same was also true for San Jose's light rail, Sacramento's light rail, and the San Diego trolley - that is, proximity < 300m to transit tracks did not lower property values on average. The EXCEPTION was Caltrain in San Mateo County, where property values did drop near the tracks. This makes sense, since Caltrain is loud, noisy, and smelly, whereas the trains that use the Union Pacific tracks next to Robson/KB are very slow moving, and who knows how often they will come now that NUMMI has closed operations. The city already has plans approved to build and underpass at Kato Rd. to allow trains to cross without lights/bells, although this may allow trains to approach faster and generate more track noise.
Hope this helps.