One of the arguments for the housing is that other airports have more of them and closer to the action, so I don't think this will be any more of a problem than at other airports?
Off the top of my head I can't think of any new build housing which as near or nearer - but there again they should know what they are buying. However, the size and location of the planned housing surely limits the use of the terminal to not much above the current levels (e.g. parking)
Also, typical DTVA timing?
UK house prices in first monthly fall for 20 months - BBC News