Draught-Proofing Myths That Keep Your Energy Bills High

It's true that older construction often has more gaps than modern building standards would allow, but that doesn't mean those gaps are inevitable or unfixable. The majority come from shrinkage around door and window frames, gaps between skirting boards and walls, and deteriorated weatherstripping — all of which respond well to widely available sealants, strips, and fillers. Treating a home as 'just draughty' is a diagnosis that leads to inaction when targeted improvements would make a measurable difference.

This myth conflates two separate systems: uncontrolled air infiltration through gaps, and deliberate ventilation through trickle vents, extractor fans, and opening windows. Sealing draughts addresses the former without blocking the latter. Condensation and mould are caused by inadequate ventilation and high indoor moisture levels — not by sealing a rattling letterbox or a gap under a door. Kitchens and bathrooms should retain working extractor fans regardless of how well-sealed the rest of the home is, and trickle vents in window frames should be kept clear.

Modern construction is generally more airtight than older stock by design, but 'newer' does not mean 'gap-free.' Pipework and cable entries through walls, gaps between window frames and masonry that open as the structure settles, and poorly installed loft hatches are all common in homes of any age. Homeowners of newer properties often skip draught-proofing entirely because of the assumption their home is already sealed — and end up with avoidable heat loss as a result.

Many sealants and adhesive products actually cure better in moderate temperatures than in very cold conditions. Applying weatherstripping or flexible filler in spring or autumn can be more practical and just as effective as a winter rush job. In summer, the same gaps that let cold air in during winter can allow warm air to infiltrate air-conditioned spaces, making draught-proofing relevant to comfort and energy use across all seasons.

Expanding polyurethane foam is useful for filling large, irregular voids around pipes or structural penetrations. However, it is too rigid for gaps that experience regular movement — such as those between timber floorboards, which expand and contract seasonally. In those locations, a flexible decorator's sealant is far more durable. Around moving parts like door frames, compressible strips outperform foam. Using the wrong material for a given gap can result in cracking, renewed draughts, and cosmetic damage that is difficult to reverse.

A door has four edges, and cold air will find whichever gaps remain open. Many homeowners fit a bottom excluder, feel a short-term improvement, and assume the job is done — while air continues to infiltrate around the sides and top of the same door. A thorough door seal involves strip products along both vertical jambs and the head (top) of the frame in addition to the threshold. Checking all four edges takes only a few minutes and makes the difference between a genuinely sealed door and a partially treated one.