Building an attractive, sturdy and weather-proof birdhouse is very easy to build. Wood is a particularly good building material because it breathes, is durable and has good insulating qualities. The ideal choices are naturally decay-resistant wood such as cedar, redwood or a good grade of exterior plywood. It should be at least ¾” thick as anything less will result to heat built-up which is very harmful to young birds. It doesn’t really matter whether the wood is slab, rough-cut or finished as long as the inside has not been treated with stains or preservatives. Fumes from chemicals are likewise harmful to the birds.
Cypress and cedar wood would require no painting but pine and plywood houses will last longer when coated with water-based exterior latex paint. Brown or dark-green stain applied only to the exterior will camouflage the house and prevent rough boards from rotting. Purple Martin houses are usually white while tan, gray or dull-green works bests for the other cavity nesting species. These colors will reflect heat and are less conspicuous to predators.
