Conservation rooflight installation in Crawley, slim and flush

A conservation rooflight is a thin-framed, flush-fitting roof window made to look like the small iron lights that old roofs once carried, and glazed to modern standards behind that traditional face. It exists for roofs where a bulky modern frame would look wrong, or would be refused.

Conservation skylight installation starts from a simple observation. An older roof is a quiet object. Its covering is laid in small units, slate or clay or stone, and its surface is broken only by a chimney, a dormer or a vent. A standard roof window sits proud of that surface on a deep box frame, with a wide flashing collar around it. From the street it reads as a square of plastic and metal dropped onto something handmade. A conservation rooflight reverses the proportions. The glass sits almost level with the roof covering, the frame is a slender section of steel or aluminium, and the flashing is worked into the slates or tiles so that it almost disappears.

That is the whole idea, and it explains the name. The product is not conserving anything by itself. It is a way of adding daylight to a house that has a character worth keeping, while asking as little of that character as possible.

Permission for a conservation rooflight depends on the building, the roof slope and the place it stands in. There is no single answer for the region, which is why the position is checked for the address before anything is priced or ordered.

Four separate questions sit behind the word "consent", and they are easy to run together.

The first is ordinary planning permission. Some houses have permitted development rights that allow roof windows on certain slopes under set conditions, and those rights can be withdrawn or never have existed for flats, maisonettes and some converted buildings. The planning authority's own pages and the Planning Portal set out the current rules. Our page on planning consent for conservation rooflights explains how the normal route runs.

The frame of a conservation rooflight is made of steel or aluminium, and the choice changes how it looks, how long it lasts and how it is finished. Neither is better in every house.

Steel has the closer resemblance to the old cast iron and wrought iron lights that once sat in barns and outbuildings. Its sections can be very thin. It is strong, and it takes a painted or galvanised finish that looks right beside aged slate. The cost of that slenderness is maintenance: a steel frame depends on its coating, and in a damp Wealden roof that coating needs to be good. Aluminium is lighter and is powder-coated to a durable finish that holds its colour. It can be formed to a slim profile, too, although the thinnest sections in the catalogue are usually steel. You can read the trade-offs side by side in steel or aluminium conservation rooflights.

Glazing bars are the next decision. A traditional roof light had a single pane or several small panes divided by bars, because large sheets of glass were not made in the eighteenth and nineteenth centuries. Adding bars can give a rooflight the period rhythm an old building expects, and it may also help an application along where a conservation officer wants the proportions to echo the original. Bars on a double-glazed unit can be real or applied, and the two behave differently inside the room, in the way they catch light and in the way a cleaner works around them. Glazing bars on conservation rooflights sets out when they are worth having and when a single clear pane is the better fit.

Conservation rooflights are commonly fixed. A few open, and some can be fitted with blinds and motors. Each of these extras has a cost in frame thickness, and that cost is what a conservation officer will look at.

Opening first. A fixed light is the slimmest and the most discreet, because it needs no hinge, no handle and no secondary frame. An opening light needs all three, and the frame grows to house them. Some makers offer opening conservation rooflights with a low profile, and they serve a bedroom or a bathroom well when a window is needed for ventilation. Do conservation rooflights open covers the choices. If you want a motor, see whether a conservation rooflight can have an electric opener, and our wider hub on electric and opening rooflight installation.

Blinds come next. A rooflight in a south-facing roof can overheat a loft room in summer, and a blind is the practical remedy. A blind also softens glare and adds a little warmth in winter. The difficulty is that a slim frame has little room for the side channels a blind needs, so the fit has to be chosen with the frame. Whether you can fit a blind to a conservation rooflight explains how the two go together, and the answer should be settled at the survey rather than after the glass is in.

Some old buildings already have a rooflight of some kind: a cast iron light in a barn roof, a small glazed opening in a Victorian outbuilding, or an early aluminium unit from the last century. Replacing these needs the same care as adding a new one, with a further question about what is worth keeping.

An old cast iron rooflight can be part of the character of a building, and in a listed building it may be part of the protected fabric. Before anyone strips it out, the question is whether it is original and whether it can continue to serve. Whether an old cast iron rooflight should be replaced with a conservation rooflight weighs the factors. If the answer is yes, the new unit is chosen to match the old in section and pattern, so the roof keeps its look while gaining modern glazing.

A newer unit that has failed is a simpler case. A unit with failed seals and misting between the panes needs renewing, and the opening is already there, which can make the planning question easier. A replacement in the same footprint and of a similar or slimmer profile is more readily accepted than a new opening, though listed buildings and designated areas still need the position checked. The hub for this work is misted and failed rooflight replacement.

Conservation rooflights sit alongside the other nine services we cover, and some houses need more than one. An old cottage with a modern rear extension might take a conservation rooflight on the original roof and a different product on the extension.

The flat-roofed extension behind an older house is a good example. The old roof takes a conservation rooflight on the slope. The extension might need a flat glass unit, which is covered in flat roof rooflight installation, or a larger glazed feature described in roof lantern installation. A stair or landing where a rooflight cannot be fitted for structural reasons may suit a light tube, and sun tunnel installation explains that route. Where the glass will be walked on, for example over a void, see walk-on rooflight installation.

The same quiet thinking runs through all of these. The aim is that the room keeps the light and loses the noise, with the fitting specified for what that particular room hears. The general page on skylight and rooflight installation in Crawley shows how the pieces fit together, and our about page explains how we work. Questions that do not fit a form can go to our contact page.