Local Shutter InstallersPlanning · Ruling
Flats and permitted development
Updated
Flats do not enjoy the same householder permitted development rights as a dwellinghouse. An external shutter on a flat is very likely to need planning permission and the freeholder.
A pane, so the rule has a house
The worked opening for Flats and permitted development is 1.2 m wide by 2.1 m high, 2.52 square metres of glass. This figure puts 645 watts per square metre on the pane and uses a g-value of 0.76, about 1235 watts into the room if the curtain is up. An opaque external shutter, taken as stopping 90 percent of that gain while it is fully down, leaves about 123 watts and keeps about 1112 watts out. That is a noon figure for comparison. An internal blind does not get the same reduction. For Flats and permitted development, 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 rule without the fog
Start there.
Winter and permission are different files
Winter figure for Flats and permitted development: glass at 2.6 W/m2K, 2.52 square metres, a 12 degree inside-outside gap and eight night hours. The bare pane is about 0.63 kWh a night on that crude sum. A closed shutter cutting about 30 percent of the flow leaves 0.44 kWh and saves about 0.19 kWh a night, only while it is down. Open it when you want winter sun.
What I would do before paying
Stop Flats and permitted development if the door is an escape route and the motor has no way to open when it is dead. A photograph is not a manufacturing size.
Cardiff is only a setting for Flats and permitted development. The streets there are not the product.
How to use the figure
The 1.2 by 2.1 metre opening inside Flats and permitted development 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 solar motor, and the illustration is £2,268. 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 Flats and permitted development, 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. Flats and permitted development covers one kind of opening. The house may have three.
When I would not order yet
Flats and permitted development 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 Flats and permitted development 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. £2,268 illustrates Flats and permitted development for a 1.2 by 2.1 metre opening with a solar motor, 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 2.52 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 Flats and permitted development 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. Flats and permitted development uses a solar motor in the example so you can see how much the motor choice moves £2,268.