Lower heat loss through the wall
The wall's U-value is the direct measure. The lower the U-value, the less heat escapes per square metre of wall.
All energy measures
Building envelope
Insulating external walls
External walls account for a large share of heat loss in older houses. Adding insulation pays off most when the wall is being opened anyway, and considerably less as a standalone project.
See what this means for your homeThis measure is relevant if
- The house was built before 1987 and the walls have little or no insulation
- The cladding is due for replacement
- You feel draughts along floors and walls on cold days
- You plan to change the heating system later and want to cut the heat demand first
What it does to energy use
More even indoor temperature
Cold wall surfaces draw heat from the room. Insulation reduces the gap between air and surface temperature, and that gap is what feels like a draught.
Lower peak demand on the coldest days
The heating system has to cover a smaller loss at the design outdoor temperature. That matters if you will size a heat pump later.
Moisture risk must be assessed
Insulation changes where the temperature drops inside the wall. Done without a vapour barrier and ventilation on the right side, it can move the condensation point into the structure.
Sequence matters
Insulation belongs among the first measures, for one reason: it changes how much heat the house needs. Replace the heating system first and you size it for a demand that disappears once the walls are insulated — leaving a system too large for the house. Building envelope before heat source applies to most homes.
Enova funding
Insulating external walls is among the measures Enova funds. How much you can receive depends on how many square metres are insulated and the U-value the wall ends up at.
Rates and terms change. What you can receive depends on the building, how the work is carried out and which schemes apply at the time. Always check Enova's own pages before relying on a figure.
The rates tell you what you can receive. The calculation tells you what the measure actually does to your home — how much it saves, what it costs, and whether it should come before or after the others.
Which measures pay off in your home?
Enter the address. Gadder collects what is known about the building, calculates the energy demand and ranks the measures by what they actually deliver.