Houses in Bouldin Creek, a neighbourhood in Austin, Texas, are cavernous, but occupy only a fraction of their plots. Rules known as the “McMansion ordinance”, intended to preserve the area’s character, ensure there is space between them. Architects must squeeze the design of a new home into an imaginary tent rising five metres from the plot’s edge, then angling in at 45 degrees. The rules seek to prevent sprawling developments from replacing small houses. Instead, the cost of complying with them has ensured that only large, expensive homes are viable.