VELUX window installation in Birmingham

A VELUX window is a roof window: a glazed frame built to lie along the slope of a pitched roof, level with the tiles or slates instead of raised on a kerb above them. People call it a skylight, and the trade calls it a rooflight or a roof window, and all three words point at the same family of product.

It suits a roof with a real slope, such as the rear pitch of a Victorian terrace in Kings Heath, a loft conversion on a 1930s semi in Erdington or the roof over a bungalow bedroom. A flat roof wants a different product, which we cover on our page about flat roof rooflights.

Before suggesting any window, we inspect the rafters, the covering and the room underneath during the survey visit.

Roof pitch and rafters

Every roof window has a range of roof pitches it is made for, and the maker states it in the product data. A shallow pitch asks for a different window and often a different flashing from a steep one, so we measure the pitch before we quote.

The rafters decide the width. Windows are made to fit between rafters that sit at standard spacings, and where yours do not, we say what trimming that means. Old roofs in older Birmingham houses are rarely perfectly regular, so we measure rather than assume.

Which one suits the room

On a centre-pivot window the hinge sits halfway up the sash, which sends the bottom edge out over the roof while the top edge comes in over your head. The handle is on the top rail, which suits a window set lower in the slope, where the handle is within easy reach and furniture can sit beneath it. Turn the sash all the way round and the outer pane faces the room, which makes the glass easy to clean from inside.

A top-hung window is hinged along its head and swings out and up. The handle is on the bottom rail, so it works well on a window set higher up the slope, and the open sash leaves a clear view out over the roofs rather than just the sky. Nothing swings into the room, so the space under the opening stays free at head height.

VELUX offers its roof windows with a timber core in two main finishes inside: clear lacquered pine, and white. The white finish is either painted or a polyurethane coating, which is the one made for rooms where steam and splashes are likely. A kitchen or a bathroom is the usual home for the polyurethane type, while a bedroom or a study can take pine if you like the grain.

Comparable windows from other makers have their own finish options. Some are timber with a white paint, others are all white, and the hardware in each can look quite different. In the written quote each option's finish is listed on a line of its own, keeping the comparison between the windows fair and level.

Pine and painted white can look very different in a room that is otherwise plain, and the choice is mostly about taste. Our job is to explain what each finish asks of you afterwards, so that nothing surprises you later.

The regulation figure

Part L 2021 sets limits on how much heat new glazing in an existing home may lose. A roof window is measured against 1.4 W/m²K, the same limit that windows generally face, or alternatively against Window Energy Rating Band B. A rooflight is held to its own figure, 2.2 W/m²K, and the maker's data sheet says which class each unit belongs to. Each roof window on your quote carries the maker's published figure, so you can see how it sits against the limit and against the others.

A window that fits within the limit is not always the best one for your room. It is the starting line, and the glass beyond that is a choice.

Roof windows face the sky, so they gain heat on a bright day and lose it on a clear night. Glass with a low-emissivity coating and a warm-edge spacer in the sealed unit helps on both counts, and gas between the panes adds to it. Triple glazing improves the winter figure again but adds weight, which the frame and the fixings are designed to carry.

Summer heat is the other half. A loft bedroom on a south or west slope in Moseley or Sutton Coldfield can get warm on a long afternoon. An external blind turns the sun away before it ever reaches the glass, whereas an internal one only softens the glare and lets more of the heat into the room. Our page on energy efficient rooflights sets out the glass coatings and the heat-loss numbers that makers print, while our answer on fitting blinds with the window shows the types of blind side by side.

What the flashing does

The flashing is the set of metal pieces around the window that carry water from the roof over and around the frame. It is what makes a roof window watertight, and each kit is made for a particular type of covering, so a window that works on one roof needs a different kit on another.

The kit also decides how the window sits in the roof. A standard kit lets the frame stand a little proud of the tiles, while a recessed kit sets it lower so that it lines up more closely with the covering and looks less obtrusive from the street. Our answer on which VELUX flashing kit your roof needs explains how kits are matched to coverings and how to read the code.

When a new window sits next to another or beside a chimney, the flashing may need to join up. Combination kits exist for windows side by side, and we show which one applies on the quote.

Old tiles and new tiles

Birmingham has plenty of roofs where the covering is original, whether clay plain tiles on a Victorian house or slate on a villa. Handling old tiles takes care: some break when lifted, and matching a replacement can take time. If any of them look likely to need replacing, you hear it from us during the survey.

A newer concrete tile is easier to lift and re-lay, but it comes in several profiles, and the flashing has to match the one on your roof.

Chimneys, valleys and neighbours

A window close to a chimney, a valley or the party wall needs extra thought. Water collects along a valley and around a stack, so we usually keep the opening clear of them by a sensible distance and place the window where the roof's structure and the drainage both agree.

Where a conservation area applies, the position and the type of window can matter to the council. Our page on conservation rooflights compares the low-profile options made for those roofs.

Reading a size code like MK04, the letter tells you the width and the digits tell you the height of the window.

A word on escape windows

On a bungalow or a chalet bungalow, a roof window can be the escape route from a room under the roof, provided that storey sits within the height that Approved Document B allows, which is 4.5m above the ground. Where a loft conversion is added to a two-storey house, the way out has to be a protected stair, since a roof window that high is out of reach as an escape route.

We check which situation you have before we recommend a window, and we say plainly when the room needs a protected stair or another way out rather than a roof window.

Planning permission

A good many roof window installations fall within permitted development, with the governing conditions laid out in our rooflight planning guide. That guide is the place to read them, and it applies to a window on a house roof as well as a flat roof.

Listed building consent has to come first for a listed property, whatever permitted development reads, and that right can also be taken away by a direction under Article 4 or by a condition attached to an earlier planning permission. What your address is subject to gets checked when we visit for the survey, and we report back on what turns up. The council makes the decision.

Birmingham districts including Moseley, Edgbaston and Harborne contain conservation areas, so the rules at your address call for a proper check before anything is ordered. Should an application turn out to be needed, we can provide the drawings and product details to go with it.

What goes into the price

A price is built from the window, its glass and finish, the flashing kit, any blind, the trimming of the roof structure, access to the roof and the lining and plaster inside. The quote breaks every option down into separate lines, so it is plain to you where the money goes.

Our answer on how much VELUX installation costs explains each part. Access is a good example: a roof that can be reached with a ladder costs less to work on than one that needs scaffolding, and a window fitted from the loft side can sometimes save the scaffold. Our answer on fitting a VELUX window from inside sets out when that works.

On a fitting day the roof is opened only as far as the window needs. Around the opening the tiles are lifted off and stacked, the frame is fixed to the rafters, and the flashing is dressed in course by course as the tiles go back.

Inside, the lining goes in last. We clear up before leaving, show you how the window and any blind operate properly, and give you the maker's paperwork, along with a Building Control certificate for any notifiable part of the job.

Blinds and finishing touches

Blinds are easiest to add when the window itself goes in, since the fixings and any electric supply can be set before the lining is finished. Blackout types suit a bedroom, pleated ones filter light in a study and heat-reducing ones help on a hot slope.

Our 10-year workmanship guarantee covers every installation, with the maker's own warranty running separately on the window itself. Our guarantee page spells out what each of the two covers.