How many BTU for 1,200 sq ft?
Updated October 24, 2026
To heat 1,200 sq ft (111 m²) you need between 18,000 and 47,300 BTU/h depending on your city and insulation. Here is the calculation city by city, using the CSA F280 method.
Assumption: a 1,200 sq ft bungalow with no heated basement, 8 ft ceilings, windows in proportion to floor area.
Heating load by city and house age
| City | After 2010 | 1990 to 2010 | 1970 to 1990 | Before 1970 | Cooling* |
|---|---|---|---|---|---|
| Vancouver (-7 °C) | 18,000 | 18,000 | 19,500 | 25,400 | 11,700 |
| Toronto (-18 °C) | 18,000 | 18,200 | 26,900 | 35,100 | 13,300 |
| Halifax (-16 °C) | 18,000 | 18,000 | 25,500 | 33,300 | 11,300 |
| Montreal (-23 °C) | 18,400 | 20,500 | 30,200 | 39,400 | 12,500 |
| Quebec City (-26 °C) | 19,700 | 21,900 | 32,200 | 42,100 | 11,700 |
| Winnipeg (-31 °C) | 21,700 | 24,200 | 35,600 | 46,400 | 12,500 |
| Edmonton (-32 °C) | 22,100 | 24,600 | 36,300 | 47,300 | 11,300 |
* Cooling for a 1990–2010 house, at the city’s summer design temperature.
Which Kanartic system for 1,200 sq ft?
Newer house in Toronto
Z-PRO 18,000 · 2 zonesfrom $3,625 · DIY
Covers 100% of the heating load at -18 °C
See on kanartic.ca1990–2010 house in Montreal
Z-PRO 27,000 · 2 zonesfrom $4,725 · DIY
Covers 100% of the heating load at -23 °C
See on kanartic.caPre-1970 house in Edmonton
ZERO 24,000 wall unit + ZERO 24,000 wall unitfrom $6,798 · DIY
Covers 100% of the heating load at -32 °C
See on kanartic.caWhat about 25 BTU per square foot?
The rule of thumb would give 30,000 BTU/h for 1,200 sq ft. The component calculation gives 18,000 to 47,300 BTU/h: depending on the house and climate, the rule is off by −37% to +67%.
Frequently asked questions
Is a 12,000 BTU heat pump enough for 1,200 sq ft?
In Montreal, for a 1990–2010 house, a 12,000 BTU unit covers 58% of the load at -23 °C; for a pre-1970 house, 30%. So you need a bigger unit or backup heat.
How many BTU to cool 1,200 sq ft?
Between 11,300 and 13,300 BTU/h for a 1990–2010 house, depending on the city. In Canada, heating sets heat pump size, not cooling.
Wall unit or multi-zone for 1,200 sq ft?
A wall unit is enough for an open area; if bedrooms are closed off, a 2-zone multi-zone heats each room better.
Other floor areas
900 sq ft1,000 sq ft1,100 sq ft1,300 sq ft1,400 sq ft1,500 sq ftAll
How many BTU for my house?Why not to oversizeHeat pump costBy room