Pelmets, explained.

What a pelmet is doing.

A pelmet is a board or a fabric-covered box fitted across the head of the curtain, projecting from the wall and returning to it at each end, so the top of the treatment is closed.

The reason that matters is airflow. At a cold window, warm room air drifts across the ceiling, chills against the glass, sinks down the pane and spreads across the floor, pulling more warm air over to be cooled in turn. That circuit is the main way a heated room loses warmth to a window overnight, and it is explained in full in the thermal curtains guide.

Now picture a curtain hanging on an exposed rod with 100 millimetres of open air above it. The warm ceiling air does not stop at the fabric. It pours over the top of the rod, straight down the back of the curtain, across the cold glass, and out at the bottom. The curtain is not in the circuit at all. You bought insulation and built a chimney. Closing that top gap is what a pelmet does, and it is the single highest-value thing you can add to a curtain that is otherwise well made.

The three ways to seal the top.

Fabric-covered pelmet.

A timber frame padded and covered in your curtain fabric or a coordinating one. It disappears into the treatment because it reads as part of the curtain, it suits soft modern interiors, and it is the most forgiving option on a slightly uneven wall because the padding takes up small variations. Cost is $180 to $450 per window supplied and installed. It is the option we specify most often in the newer estates around Officer.

Timber or MDF pelmet.

A painted or stained board, sometimes with a moulded profile or a simple square edge. It reads as architecture rather than soft furnishing, which is why it suits period frontages and formal rooms in Berwick, and it can be painted to match your existing trim so it looks original. Cost is $200 to $600 per window. It is more rigid than a fabric pelmet, so the wall needs to be reasonably true, and it is the better choice if you want a crisp line.

A plasterboard bulkhead, or a close ceiling fix.

Many newer homes are built with a plasterboard bulkhead or a recessed curtain pocket above the window. If you have one, the track fixes up inside it and the top is already sealed with no pelmet required. Even without a bulkhead, if the window head is close enough to the ceiling that the track can be fixed hard against the ceiling itself, you get the same seal for nothing extra. This is the cheapest good answer and it is why we always check the head height at the measure before quoting a pelmet you may not need.

A pelmet only works with a return.

Sealing the top and leaving the sides open moves the problem rather than solving it. The pelmet has to return to the wall at each end, and the curtain track underneath it has to bend back to the wall too, so the fabric physically meets the wall instead of ending in mid air. On a pair of curtains you also want an overlap arm at the centre so the two leading edges cross. Those details cost very little and they are non-negotiable if warmth or true darkness is the point. For the darkness side of it see bedroom blockout curtains.

How deep and how wide?

A pelmet has to be deep enough front to back to clear the curtain stack behind it, including the heading, the runners and the fullness of the fabric where it gathers. Too shallow and the curtain rubs or the pelmet sits proud of the fabric awkwardly. It also has to be tall enough to cover the track and the top of the heading, and wide enough to run past the opening on both sides so the curtain can stack off the glass. Those three measurements are worked out on site, which is one of the reasons a pelmet is not something to order off a size you measured yourself.

Why builders leave them out.

Strictly speaking builders are not leaving out the pelmet, they are leaving out the entire window treatment. Curtains, blinds, tracks and pelmets are almost never in a base build contract, so every new home in the Pakenham estates arrives with bare windows and no bulkhead unless it was specified and paid for as an upgrade. Pelmets also went out of fashion for a couple of decades, associated with heavy older interiors, and are only now being asked for again because people have worked out what they were for. If you are building and you get the chance, specifying a bulkhead or curtain pocket at frame stage is cheaper and neater than any pelmet you can add later.

When we would tell you to skip it.

• You already have a bulkhead or the track can be fixed hard to the ceiling
• The window is in a room you do not heat and do not sleep in
• A blind behind the curtain is doing the light and heat work and the curtain is purely decorative
• Budget is tight and the money is better spent on floor-length drops and returns first

Where we would not skip it: any bedroom where somebody sleeps during the day, any large single-glazed window in a room you heat, and any hills house in Emerald or Pakenham Upper where the overnight loss is worst.

Frequently asked questions.