Shading roof lanterns and Velux windows

Two kinds of roof glass

A roof window is a single manufactured unit in the slope, with a size code and a maker. Velux dominates that market in Britain, and Velux sells blinds and shutters, including solar versions, for its own windows. The shutter is an accessory to that window, not a general roof blanket.

A lantern is a raised glass roof on a kerb, often made from separate panes and bars. It does not have a Velux size code. A roller shutter from the bifold range cannot be bent over it. Treat any quote that uses one price for 'the glass roof' as unfinished.

Why the lantern hurts more

High summer sun hits roof glass more directly than it hits a vertical door. The heat arrives over the table, which is why people describe a lantern as unbearable even when the doors are shaded. Internal lantern blinds exist and suffer the same fate as internal door blinds: they are behind the glass.

External lantern shading is a specialist product, sometimes a tensioned screen, and it has wind and waterproofing details that a window shutter fitter may not know. If you cannot find a credible external option, the honest alternatives are better glass at the next replacement, or a solid roof and a rooflight that can take a proper blind or shutter.

Velux, specifically

Match the shutter or blind to the window code. Solar versions suit roofs where you do not want a cable dragged through the lining. Mains versions suit a refit where the cable is easy. An old or non-Velux window may not accept the accessory. Do not order from a photograph of the reveal.

Access is the labour. A low roof over a flat extension might be reached carefully. A steep tile slope is a scaffold conversation. The accessory can cost less than the access. Put both on the quote.

Loft bedrooms

Lofts overheat because the slope sees sun all day and the room is small. A roof window shutter plus ordinary ventilation is the right toolkit. A vertical shutter on a dormer cheek only helps the cheek. If the hot pane is the one in the slope, buy for the slope.

Dawn light in an east-facing roof window is a timer job. Blackout is a product option, not the default of every blind in the range. Say if shift work is the reason.

What not to buy

A set of facade shutters for the kitchen doors, sold as the cure for a lantern you can still see the sky through. Window film on a lantern as a casual first try, without the glass maker's view on thermal stress. A plantation shutter in a loft reveal that does not actually cover the pane in the slope.

Also do not assume Part O of the building regulations will specify a product for your 2009 extension. That document shapes new homes. Your lantern is a practical problem, not a regulation you can quote at a fitter to make them responsible for the temperature.

A clean brief

List every pane that sees the sky: doors, sidelights, lantern, roof windows. Next to each, write hot, bright, or fine. Buy shade only for the ones that are hot or bright, using a product that can actually reach that pane.

If the lantern is the only misery and nobody will make an external shade you trust, say so and spend the money on glass or on a different roof, rather than on a wall shutter that will be blamed for a job it could not see.

Name the pane before the product

Write a list: bifold, side light, lantern, roof window over the stair, dormer cheek. Put a tick next to the ones that are hot or blinding. Only then pick a product, and only a product that can touch that pane. A wall shutter ticked against a lantern is a category error you can catch in pencil.

Roof windows have maker codes. Lanterns have widths, bar layouts and a kerb. Those are different orders of information. A fitter who measures a Velux as 'about a metre of glass' is not ready to order the shutter that has to match the flashing.

Access is often the money

The accessory for a single roof window can be a smaller invoice than the scaffold that reaches it. Say so on the quote. Internal fitting is sometimes possible and sometimes a lie told to avoid the scaffold price. Ask which, and what happens to the lining if someone is wrong.

Lanterns over a single-storey extension are easier to reach and harder to shade well. External fabric systems and replacement glass are the grown-up options. A roller borrowed from the door range will not bend over the hip of the lantern, whatever the drawing on the tablet suggested.

Heat you feel on your head

Sit in the usual chair at the usual hot time. If the discomfort is overhead, buying door shutters is a distraction with a long lead time. You will be cross with an innocent cassette. Fix or accept the lantern first, then see whether the doors still need help.

Loft bedrooms are the other version of the same mistake: the slope is the collector, the little vertical shutter on the dormer cheek is a side issue. Spend the money on the slope. Leave the cheek until someone is actually bothered by it.

What I would put on the drawing for Shading roof lanterns and Velux windows

A plan of the rear, a section through the head, the box projection, the guide face, and the lantern marked as excluded if the shutter cannot see it. The stand-in house is in Reading. Leaseholders without a private rear wall should hear a no early. Colour as a RAL or a frame foil, looked at in daylight, not a phone photo taken after rain.

Sizes at three heights. 4.2 by 2.35 metres is only the illustration inside Shading roof lanterns and Velux windows, so the drawing of the real house replaces it. If two firms disagree, do not average the tapes. Watch one of them measure again.

Sun and the night, on that drawing

The worked opening for Shading roof lanterns and Velux windows is 4.2 m wide by 2.35 m high, 9.87 square metres of glass. This figure puts 545 watts per square metre on the pane and uses a g-value of 0.76, about 4088 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 409 watts and keeps about 3679 watts out. That is a noon figure for comparison. An internal blind does not get the same reduction. For Shading roof lanterns and Velux windows, use the noon figure to compare two openings on the same house, then let a measured survey replace the figure.

Winter figure for Shading roof lanterns and Velux windows: glass at 2.6 W/m2K, 9.87 square metres, a 12 degree inside-outside gap and eight night hours. The bare pane is about 2.46 kWh a night on that crude sum. A closed shutter cutting about 30 percent of the flow leaves 1.72 kWh and saves about 0.74 kWh a night, only while it is down. Open it when you want winter sun.

Use the dusk habit in the explanation so the household does not judge the product only in July. Use the product in both seasons or admit you bought a summer gadget. Shading roof lanterns and Velux windows is a poor purchase if the curtain will live in the box from September.

Money, exclusions, and the neighbour's Munich photo

Fitted illustration for Shading roof lanterns and Velux windows in Reading: £6,308 at September 2026 prices, for this 4.2 by 2.35 m opening with a solar motor. The figure allows a front-mounted aluminium curtain and ordinary fixing. It does not include scaffold, a rebuilt soffit, planning drawings, or a new window. A second opening on the same visit usually costs less than the first, because the van is already there. Compare two quotes only when the slat, the box and the drive match.

A patio shutter and one or two bedroom windows, surveyed, made to measure. Copy the principle of an external curtain, not a postcard of a street whose walls were built around the box. Shading roof lanterns and Velux windows on a British rear extension is often the honest version. Shading roof lanterns and Velux windows on a listed sash front is often the version that should stop.

Stop Shading roof lanterns and Velux windows 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.

What to do with this note

Shading roof lanterns and Velux windows is a long note because the decision is a pile of smaller ones: which pane, which side of the glass, which box the wall can carry, whether anyone may refuse the look, and whether you will actually lower the curtain. The 4.2 by 2.35 metre example, the solar motor, and the £6,308 illustration are there so those decisions have numbers attached. They are not an order form.

Take the openings that hurt into a survey. Leave the ones that do not. Ask the fitter to repeat the brief in a sentence you recognise. If they cannot, you are being sold a range rather than a remedy. Compare the next quote against the slat, the drive and the exclusions, not against a single bold total.

Keep the summer close and the dusk close as separate habits. Shading roof lanterns and Velux windows fails if the hardware is perfect and the curtain stays in the box. It also fails if you fit it on a front the council will make you remove. The successful version is smaller than a whole-house fantasy and more specific than an advert for German streets.

Questions worth asking the fitter

Can I put a normal roller shutter on a lantern?

No. Lanterns are not a rectangular wall opening. They need their own shading design.

Are all roof blinds external?

No. Many roof window blinds sit inside the pane and mainly control light. Ask whether the product is outside the glass if heat is the reason.

Does a Velux shutter fit other brands?

Assume no. Match the maker and the size code.

Sources

• Velux UK
• ES-SO, European Solar Shading Organization
• Planning Portal
• GOV.UK: building regulations