Materials for a Squirrel House (Churchgate EN7)

I’m looking for materials to build a safe and natural wooden squirrel house.

I’m mainly looking for untreated, non-toxic wood or wooden boards, small pieces of timber, plywood, screws and other suitable DIY materials. Reclaimed or leftover materials are very welcome.

Ideally, the wood should be strong enough for outdoor use and free from paint, chemicals or harmful treatments. Small offcuts and leftover pieces are also useful.

I’m happy to collect locally.