Smart Home Energy 
If you feel cold air blowing through your letterbox every winter, this internal flap seals the gap for a tenner — fits most doors, takes five minutes to screw on, and you can still get your post.
Problem it solves
Stops cold draughts and heat loss through the letterbox opening, reducing heating costs and improving comfort near the front door.
Who it's for
Homeowners and renters with internal letterboxes on wooden or uPVC doors who want to reduce draughts without blocking post delivery.
Why we recommend
Works on wood or uPVC doors, takes five minutes to fit and pays back in one winter.
Savings
- Typical annual saving
- £10–£30/year depending on door position and heating usage
- Payback period
- Under 1 year
