Our birdhouses are fully functional and are constructed to be left outside year round. All are designed for easy installation. We only use 16 oz roofing copper and 32 gauge roofing aluminum on our tops. The primary construction material for the body is 3/4″ Medium Density Overlay (MDO), or Texture 1-11. MDO is a product designed for outdoor exposure and does not delaminate or separate when exposed to the elements. All birdhouses come with easy cleanouts.