Did you mean a house to raise butterfly caterpillars in? If you're talking about a house for adult butterflies...well, instead of a butterfly 'house', I'd just include plants in the garden that butterflies like...the nectar plants and the host plants. With the nectar plants, you provide nectar for the adult butterfly. On the host plants, the butterflies might lay eggs, then the caterpillars feed on the host plant until it's ready to pupate.
http://www.thebutterflysite.co...
There are lists of plants elsewhere on the forum you posted on.