There’s a particular kind of cold that British homeowners know well. You’re sitting on the sofa on a winter’s evening, the heating is on, and yet there’s still a chill creeping into the room from somewhere. Nine times out of ten, the culprit is the windows.

Draughty windows are incredibly common in older UK homes, and while secondary glazing or full window replacement are options, they’re expensive ones. The good news is that the right window treatments can make a genuinely noticeable difference to how warm your room feels, without a builder in sight.

Why Windows Lose So Much Heat

Even when windows are closed, they lose heat in two key ways. The first is through the glass itself, which conducts cold far more readily than a solid wall. The second is through gaps around the frame, where older seals have worn away over time. Thermal curtains and well-fitted window coverings tackle both of these issues by creating a barrier between the cold glass and the rest of your room.

The important word here is well-fitted. A curtain that lets cold air sneak around the edges or pool underneath isn’t doing the job properly, which is precisely why made-to-measure curtains are so much more effective than off-the-shelf alternatives in draughty rooms.

The Most Effective Curtain Linings For Warmth

The fabric on the front of your curtain gets all the attention, but for genuinely draughty windows, the lining is where the real work happens.

Thermal interlining is the gold standard for warmth. It’s a thick, wadded layer that sits between the curtain face fabric and the standard lining, and it transforms even a lightweight curtain into something far more insulating. Homes with older sash windows or single glazing will feel the benefit almost immediately.

A blackout lining also performs well thermally, as the dense weave blocks both light and cold air more effectively than a standard lining. For bedrooms with draughty windows, a made-to-measure blackout curtain with a thermal or blackout lining is one of the most practical upgrades you can make.

Getting The Fit Right

For thermal curtains to work properly, the fit matters as much as the lining. Curtains need to be wide enough to overlap generously in the centre when closed, and long enough to either touch the floor or puddle slightly. Any gap at the bottom allows cold air to circulate freely behind the fabric, which undoes a lot of the insulating benefit.

Hanging your curtain pole closer to the ceiling rather than just above the window frame also helps, as it reduces the amount of cold glass that’s left exposed at the top.

Layer Up For Maximum Impact

For particularly draughty windows, layering works brilliantly. A made-to-measure Roman blind or roller blind fitted close to the window recess, combined with full-length thermal curtains over the top, creates two separate barriers against the cold. It’s a combination that interior designers use regularly in period properties and older homes across the UK.

If draughty windows are taking the edge off your winter comfort, the right curtains really can help. Browse made-to-measure curtains that can all be created with thermal interlining from The Sewing House, and find the perfect combination to keep the cold where it belongs.