Typical tiny home BTU ranges
Most tiny homes are 200–400 sq ft on the main floor. Well-insulated builds with spray foam often calculate 6,000–9,000 BTU — retail minimum is usually 9,000 BTU.
400 sq ft with average insulation and a galley kitchen often lands at 9,000–12,000 BTU. Open lofts with 10–12 ft peak ceilings may need 12,000–18,000 BTU when you enable high-ceiling adjustment.
These are planning estimates — verify with your actual insulation, window count, and climate before buying equipment.
One head for the whole tiny home
- Mount the head in the main living area where airflow reaches the loft opening
- Sleeping lofts above the head benefit from rising cool air — add a circulation fan if hot spots persist
- Bathroom doors left open share load; closed wet baths add humidity — consider exhaust fan use
- THOWs with flex at the hitch: if walls feel drafty, choose poor insulation or upsize one BTU step
THOW vs foundation tiny home
Foundation-built tiny homes with fixed walls often seal better than THOWs that flex in transit. Stationary THOWs skirted and sealed can match foundation performance.
Use the tiny home calculator defaults, then adjust insulation honestly. Upsizing without fixing air leaks wastes money long term.