The USA-based Concrete Change website has some interesting points to make about costs and other issues related to housing design. When talking about the costs of including basic access features in new homes, we should also discuss the cost of NOT including those features.
Download an academic article from the Journal of the American Planning Association, by Smith, Rayer and Smith (2008) that spells out the economic argument using economic methodologies. The key point is that conservatively, a new home built today with a minimum of four different households over its lifetime is 65% likely to have an occupant with a permanent disability. If we include visitors the likelihood rises to 91%. It is often forgotten that people with disability live in families – not alone. This is an open access article.