Energy-Efficient Front and Back Doors

An energy-efficient door keeps heat in through four things: an insulated leaf, an insulated frame, efficient glass and a tight seal all the way round. Our composite doors have a solid insulated core behind a tough outer skin, and our uPVC doors are built on a 70mm multi-chamber Eurocell Logik profile. Both are made to measure and fitted by FENSA and CERTASS registered installers, so the door fits the opening closely and the job is certified under Building Regulations.

Older timber and early uPVC doors tend to lose heat in predictable places: gaps where the door has dropped or warped, thin single-skin panels, cold glazing and worn seals. Replacing the whole doorset, not just the leaf, deals with all of them at once.

Both can be very warm doors. A composite door's insulated core and thick leaf give it weight and a solid feel, and the outer skin resists weather without painting. A uPVC door is lighter, relies on its chambered profile and insulated panels, and is a good-value choice for back and side doors. On our uPVC French doors the site quotes a 1.2 W/m²K whole-door U-value with warm-edge spacers.

Which is right depends on the look you want, how exposed the door is and your budget. We talk through both at survey.

Glass is often the coldest part of a door. Double-glazed units with low-emissivity glass and warm-edge spacer bars reduce heat loss and the cold edge that causes condensation. Obscure and decorative patterns keep privacy without giving up the thermal benefit. If you want lots of light and warmth together, a smaller glazed area in the leaf with a glazed side panel can be a good balance.

A well-made door fitted out of square will still let draughts in. Our installers fix, level and pack the frame so the door closes evenly on its seals, then seal the gaps between frame and wall inside and out. The threshold is set so it seals against the bottom of the door while suiting your step and any level access needs.

Multi-point locking also helps: when you lift the handle, the locks pull the door tight against the seals at several points, not just one, which is good for security and for keeping out draughts.

The features that keep heat in tend to make a door stronger too. Our composite doors are tested to PAS 24:2022, and our uPVC doors use a PAS 24 doorset with a TS007 3-star anti-snap cylinder as standard. You get a warmer hallway and a more secure home from the same upgrade. Finance is available through our FCA-authorised arrangement (FCA 1055332).

If you are not sure whether your door is losing heat, a few simple checks help. Hold the back of your hand near the edges and letterbox on a cold, windy day and feel for moving air. Look for daylight around the frame. Check whether the door has dropped and catches on the frame, or whether the handle has to be forced to lock. Look at the glass for misting between panes. Any of these suggest the door is no longer sealing well, and a made-to-measure replacement fitted square will usually solve the problem.