Simple Building Heat Loss Calculator
Estimate design heat loss from heated floor area, a specific heat-loss coefficient, temperature difference and allowance.
Formula
Planning estimate. Check product specifications and local requirements before purchasing.
Worked example: Heat Loss Calculator
Measurements in this example
| Heated floor area | 100 m² |
|---|---|
| Specific heat-loss coefficient | 0.9 W/m²K |
| Indoor to outdoor temperature difference | 32 K |
| Design allowance | 10 % |
Calculated quantities
| Design heat loss | 3.17 kW |
|---|
What to check
This calculation uses: Heated floor area, Specific heat-loss coefficient, Indoor to outdoor temperature difference, Design allowance. It returns: Design heat loss.
Use the winter design temperature for the location and the intended indoor temperature. Separate rooms with different exposure.
This simplified estimate is useful for planning. A room-by-room fabric and ventilation calculation is needed for final system design.
Use the units beside each field. The values in the worked example are starting inputs; replace them with your measurements and the specifications of your material.
Compare alternatives
Open a tool, enter your measured dimensions, then save an estimate. Keep another version if you want to compare products or allowances.