Windows and external doors are often the weak link when it comes to keeping our homes warm. Single glazing, poor seals and cracks can all add significantly to a loss of heat and discomfort.  These faults can often be fixed quite simply.


uPVC windows and doors can often be adjusted quickly and easily to improve the seal against the frame, helping to reduce draughts.  The locking bolts on the edge of the frame around the window/door can be twisted with an allen key to move outwards, making it close more snugly against the outer frame.  Likewise, uPVC door hinges can sometimes be adjusted with an allen key if a draught occurs on that side of the door.

Cracks around doors and windows are very common sources of draughts.  Even hairline cracks can let through a surprising amount of cold air.  Cracks between the window frame and the reveal (the window opening in the wall) should be sealed with silicone sealant or decorators caulk.

If you have single glazing, then replacement with double-glazing is usually the best option. Sadly, this is not always possible. Alternatives include

  • professional secondary glazing such as Magneglaze
  • DIY secondary glazing using heat-applied window film or acrylic sheets and magnetic tape;
Costs and savings

Approximate costs and savings:

  • £0 - adjusting doors and windows to close more snugly costs nothing. 
  • £few - sealing cracks costs just a few pounds using a tube of mastic and a mastic gun
  • £5 – window film
  • £several hundred – professional secondary glazing. 

Depending on which approach you take, you can achieve savings of up to £150 a year.


Home Energy – Windows and Doors (L1)                                             


Windows and doors - L1.pdf141.47 KB