The leakage figure is the measure
Airtightness is measured with a blower door test and given as air changes per hour at 50 pascal. That is the figure a calculation uses.
All energy measures
Building envelope
Sealing around windows and doors
Air leaking out through gaps takes the heat with it, and the leaks usually sit where structures meet: around frames, at skirting boards and where the wall meets the roof.
See what this means for your homeThis measure is relevant if
- You feel draughts at window frames and door thresholds
- The house is older and has never been pressure tested
- Light or sound passes around an external door
- You want an effect from a small budget
What it does to energy use
Draught feels colder than it is
Moving air draws heat from the skin faster than still air. A leaky room therefore feels colder than the thermometer shows.
Low cost, immediate effect
Sealant, weatherstripping and new door seals cost little against most other measures, and the effect arrives at once.
Sealing requires ventilation
A tighter house does not air itself. Without adequate ventilation you move the moisture problem into the structure.
Sequence matters
Sealing comes first. It is the cheapest, it affects every other measure, and a leaky house makes both insulation and balanced ventilation worth less than they should be. Make sure the ventilation keeps up at the same time.
Enova funding
Air sealing is not a measure of its own on Enova's list. Energy-efficient windows and external doors are, and sealing is often done in the same round. Treat sealing as something you do for the effect, not for the grant.
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.