Yes, genuinely — though not by as much as sealing a whole house properly. A draught excluder is a cheap first step, not a replacement for insulation, and it's worth knowing which one it actually is before you spend on either.
Where the heat actually goes
The Energy Saving Trust estimates that draughts through gaps around doors, windows and floors can account for a meaningful share of a typical home's heat loss — not the biggest share, which is usually the walls and roof, but one of the cheapest to fix. Sealing draughts is routinely one of the lowest-cost, fastest-payback improvements a household can make, precisely because a door snake costs a few pounds and takes seconds to put in place, unlike loft or cavity wall insulation.
Why a terrace loses heat differently to a detached house
In a mid-terrace, the front and back doors do most of the damage, since the party walls either side are typically better insulated by virtue of a heated neighbour on the other side. In a detached or end-of-terrace house, external walls and any side doors add to the list. Either way, the principle is the same: find the gap, block the gap.
Where to start
In order of the most common places heat actually escapes through gaps:
- The front door, especially the bottom edge and letterbox
- Any secondary door — back door, side door, internal door to an unheated hallway
- Ill-fitting sash or older casement windows
- Gaps around loft hatches, which are often overlooked entirely
A weighted or adjustable excluder handles the first two in minutes, with no tools and no cost beyond the excluder itself.
What it won't fix
A draught excluder blocks air movement through a specific gap. It does nothing for heat lost through an uninsulated loft, single glazing, or solid walls with no cavity fill — those need proper insulation work, and no amount of door snakes changes that. Think of it as the first, cheapest layer, not the whole job.
Worth doing regardless
Even in a well-insulated house, a cold draught along the floor is uncomfortable in a way that shows up on a thermostat before it shows up on a bill — people turn the heating up to compensate for a cold ankle, which costs more than the draught itself would. See the range if a few pounds now sounds better than a higher bill through December.