Smart Home Energy 
If you've got a draughty letterbox and can feel cold air pouring through in winter, this metal excluder seals the gap from inside — takes ten minutes to fit, works for renters or owners, and stops you heating the street.
Problem it solves
Stops cold draughts coming through the letterbox, reducing heat loss and cutting heating bills in homes with standard 293mm letter plates.
Who it's for
Homeowners and renters with draughty letterboxes on wood or uPVC doors who want a quick fix to stop heat escaping without replacing the whole door.
Why we recommend
Metal provides a longer lasting solution than the plastic versions.
Savings
- Typical annual saving
- £10–£30/year depending on house type and heating costs — letterboxes are a minor but noticeable heat loss point
- Payback period
- Less than 1 year
