How to Build an Outdoor Shelter (Alley Cat Allies)

Two combined pages from the leading US feral-cat advocacy organization, publication date not stated.

The canonical design

Nested-tub double-wall method: outer ~30-gallon tub, inner ~20-gallon tub, gap packed with straw, thin Styrofoam base slab — directly analogous to a double-wall insulated OSB box. Entrance is a repurposed flowerpot with the bottom cut out, inset through matching holes in both walls — a useful precedent for a sealed, insulated entrance sleeve/collar rather than a bare cut hole.

From the gallery

Single-entrance designs retain heat better than dual-exit ones; door flaps/overhangs are recommended as add-ons; lightweight materials (plastic) give less predator protection than wood — reinforcing OSB as a reasonable structural choice over plastic tubs for predator resistance.

Gap

Neither page addresses summer heat, ventilation sizing, or condensation — Alley Cat Allies’ guidance is winter-shelter-first, a real limitation given a South Texas build’s summer heat-stress priority.

Why it matters for this archive

The most-cited “established standard” organization in this space, even though its specs are cold-weather biased and must be supplemented for the summer/heat side of any South Texas design.