Local Shutter InstallersWinter · Season
Single-glazed sash windows
Updated
Old single glazing is where a night cover feels most obvious. It is also where a street-facing box is most likely to be unacceptable.
When the curtain has to be down
Rear or hidden openings are the easier fit. On a protected front, secondary glazing or internal shutters may be the lawful comfort, and they are thermally different.
A size you can argue with
The worked opening for Single-glazed sash windows is 4.2 m wide by 1.2 m high, 5.04 square metres of glass. This figure puts 520 watts per square metre on the pane and uses a g-value of 0.63, about 1651 watts into the room if the curtain is up. An opaque external shutter, taken as stopping 80 percent of that gain while it is fully down, leaves about 330 watts and keeps about 1321 watts out. That is a noon figure for comparison. An internal blind does not get the same reduction. For Single-glazed sash windows, use the noon figure to compare two openings on the same house, then let a measured survey replace the figure.
An internal blind does not get that reduction, because the energy has already crossed the glass.
The night cover
Winter figure for Single-glazed sash windows: glass at 1.2 W/m2K, 5.04 square metres, a 12 degree inside-outside gap and eight night hours. The bare pane is about 0.58 kWh a night on that crude sum. A closed shutter cutting about 18 percent of the flow leaves 0.48 kWh and saves about 0.10 kWh a night, only while it is down. Open it when you want winter sun.
A bad reason to proceed
Stop Single-glazed sash windows if the frame cannot take a guide and the wall beside it is crumbling. A photograph is not a manufacturing size.
Oxford is only a setting for Single-glazed sash windows. The streets there are not the product.
How to use the figure
The 4.2 by 1.2 metre opening inside Single-glazed sash windows is there so a quote has something to disagree with. If the tape gives a different size, the tape wins.
The example drive is a belt, and the illustration is £3,906. A belt, a wired motor and a solar motor can share a curtain and still be different jobs. Compare those lines, not a single bold total.
What the survey still has to write down
For Single-glazed sash windows, ask where the box lands, what colour reference will be ordered, and how the curtain opens when the motor is dead. Those three answers move the job more than a rounded price.
Leave the lantern, the side light and the next elevation off the order unless they are drawn. Single-glazed sash windows covers one kind of opening. The house may have three.
When I would not order yet
Single-glazed sash windows should wait if the opening is an escape door with no way to raise a dead motor, or if the front is the elevation a conservation area was drawn to protect.
A photograph is not a manufacturing size. Two quotes for Single-glazed sash windows only compare when the slat, the box and the drive are the same kind of thing.
Questions worth asking the fitter
Is the price on this page a quote?
No. £3,906 illustrates Single-glazed sash windows for a 4.2 by 1.2 metre opening with a belt, at September 2026 rates. Your survey replaces it.
Does the shutter cover every pane?
It covers the opening it is built for. Here that example is 5.04 square metres. A roof lantern, a side light or the next elevation is another line.
What if planning is unclear?
Do not pay the factory for Single-glazed sash windows until a listed building, a conservation front, a flat or a shopfront has a written answer. Ordinary rear walls on houses are sometimes simpler.
What should two quotes share?
The same openings, the same slat type, and the same drive. Single-glazed sash windows uses a belt in the example so you can see how much the motor choice moves £3,906.