How many BTU for 700 sq ft?
Updated October 24, 2026
To heat 700 sq ft (65 m²) you need between 10,500 and 12,800 BTU/h depending on your city and insulation. Here is the calculation city by city, using the CSA F280 method.
Assumption: a 700 sq ft main-floor room, two exterior walls, 5 windows, 8 ft ceiling.
Heating load by city and house age
| City | After 2010 | 1990 to 2010 | 1970 to 1990 | Before 1970 | Cooling* |
|---|---|---|---|---|---|
| Vancouver (-7 °C) | 10,500 | 10,500 | 10,500 | 10,500 | 3,600 |
| Toronto (-18 °C) | 10,500 | 10,500 | 10,500 | 10,500 | 4,100 |
| Halifax (-16 °C) | 10,500 | 10,500 | 10,500 | 10,500 | 3,400 |
| Montreal (-23 °C) | 10,500 | 10,500 | 10,500 | 10,700 | 3,800 |
| Quebec City (-26 °C) | 10,500 | 10,500 | 10,500 | 11,400 | 3,600 |
| Winnipeg (-31 °C) | 10,500 | 10,500 | 10,500 | 12,600 | 3,800 |
| Edmonton (-32 °C) | 10,500 | 10,500 | 10,500 | 12,800 | 3,400 |
* Cooling for a 1990–2010 house, at the city’s summer design temperature.
Which Kanartic system for 700 sq ft?
Newer house in Toronto
ZERO 12,000 wall unitfrom $2,349 · DIY
Covers 100% of the heating load at -18 °C
See on kanartic.ca1990–2010 house in Montreal
ZERO 12,000 wall unitfrom $2,349 · DIY
Covers 100% of the heating load at -23 °C
See on kanartic.caPre-1970 house in Edmonton
ZERO 18,000 wall unitfrom $2,895 · 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 17,500 BTU/h for 700 sq ft. The component calculation gives 10,500 to 12,800 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 700 sq ft?
In Montreal, for a 1990–2010 house, a 12,000 BTU unit covers 100% of the load at -23 °C; for a pre-1970 house, 100%. So it is enough for a newer or renovated house.
How many BTU to cool 700 sq ft?
Between 3,400 and 4,100 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 700 sq ft?
A single wall unit is enough for a room this size.
Other floor areas
400 sq ft500 sq ft600 sq ft800 sq ft900 sq ft1,000 sq ftAll
How many BTU for my house?Why not to oversizeHeat pump costBy room