Skylight and rooflight installation in Maidstone

The benefits of daylight from above

Brightness during the day is the obvious gain: fewer lamps on at lunchtime, and a room people stay in. How the room feels changes as well. Daylight shifts through the day and with the weather, and a room lit from above keeps that link with the outside even with no view, which you notice most between November and February. Space comes into it too. A rooflight takes no wall, so it leaves room for cupboards, shelving and radiators, and in a bedroom the bed can go where the room works best.

A large area of glass on a south-facing slope can overheat a room in July unless the glazing or a blind deals with it, and a roof window over a bed lets in the early light of a summer morning. Solar control glass, a blackout blind or a move to another slope answers each of these.

Rooms that gain the most

The rooms that change most sit in the middle of the plan: an inner hall, a landing with no outside wall, a box room whose one window faces the house next door. Our guide to lighting the middle of the house explains why those spaces go dark. Kitchens come close behind, because a kitchen extension often has a deep footprint and a worktop that faces away from the garden. Loft rooms are the other big group. A loft bedroom or study with a single gable window is bright at one end and gloomy at the other, and roof windows on the slope even that out while adding a little headroom near the glass.

An internal en suite has no window at all, and a bathroom with one small obscured pane is not much better. Either can be lit from the roof by a window, or by a sun tunnel when headroom in the loft is short. An opening unit also clears the steam after a shower.

Flat roofs

Flat roof rooflights sit on a kerb or upstand, so water runs off the glass and away from the joint. A fixed unit suits a single-storey extension where light matters more than air. Electric opening rooflights add a motor so the glass lifts for air, often with a rain sensor that closes it when a shower arrives. Where people will stand on the roof, as on a terrace or a balcony over a kitchen, walk-on rooflights use thick laminated glass rated for foot traffic and sit almost flush, so there is nothing to trip on.

Roof lanterns are the pitched glass structures that sit over a flat roof, usually above a kitchen, a dining space or a garden room. Their sloping panes catch light from several directions and lift the ceiling height in the centre of the room. A lantern is made to measure for its opening, so the kerb is built first and the frame follows its exact dimensions.

Pitched roofs

Roof windows sit in the plane of the slope and open on a centre pivot or a top hinge. They are the usual choice for loft conversions, landings under a pitched roof and bedrooms in the eaves. VELUX windows come in a published set of size codes, and we fit and replace them across that range. Where an old unit of another make comes out, we measure the frame and the opening before choosing its replacement.

Conservation rooflights have a slim steel or steel-look frame and a low profile, with a central glazing bar on many models. They suit older houses, slate and Kent peg tile roofs, and homes where the planners want the roof to keep its traditional look.

Rooms without a roof above

Some dark spaces have no roof directly over them. A ground-floor hall in a two-storey house has a bedroom on top. Sun tunnels deal with that: a small dome on the roof, a mirrored tube through the loft and a diffuser in the ceiling below. You get no view through one, but it brings daylight to a dim corridor.

Upgrades and tired glass

Energy efficient rooflights replace older glazing with modern units that hold heat in better and meet today's Building Regulations limits. Misted rooflights are the ones where the seal between the panes has gone and moisture sits inside the glass; the answer is a new sealed unit or a new rooflight, depending on the frame.

Roof windows come in set sizes but are chosen to suit your rafters and your room; flat rooflights and lanterns are often made to measure. Either way, we take the measurements ourselves on site, with a tape across the rafters or round the kerb.

The survey

Everything starts with a free survey at your home. Outside and in the loft, we check the pitch, the covering, which way the rafters or joists run, and whether pipes, cables or a chimney are in the way. In the room below, we note where the light needs to land and where the furniture goes. We measure the opening we have in mind and check it against the sizes that fit between the timbers, and if you are unsure whether your roof can take one at all, our answer on adding a skylight to an existing roof covers the same checks. On a flat roof we look at the build-up, the falls and the state of the covering around the spot. The survey is also when we check planning and Building Regulations for your house, so the quote reflects the real job.

The quote

After the visit you get a fixed written quote that holds on the day.

Opening the roof

On fitting day we protect the room below first, with dust sheets and boards over the floor. On a pitched roof the tiles or slates around the opening are stripped and set aside for reuse, then the battens and felt are cut. Where the window is wider than the gap between two rafters, the opening is trimmed: the rafter is cut and new timbers carry its load across to the rafters either side. On a flat roof the deck is cut, the joists trimmed the same way, and an insulated timber kerb is built to carry the rooflight.

Making it weatherproof

We fit a flashing kit matched to the covering, profiled for tiles or low-profile for slate. The underlay is dressed into the frame, the flashing fitted, and the tiles or slates laid back around it. On a flat roof the waterproofing is turned up the kerb and sealed before the rooflight goes on.

Finishing inside

Inside, the reveal around the window is lined, insulated and plastered, so the opening reads as part of the ceiling. Splaying the reveal outwards at the bottom spreads the light wider across the room. Then we clean up, lift the protection and show you how the window works, including any blinds or controls.

Sign-off and paperwork

Where the work is notifiable, we handle the Building Control notification, and the local authority or a registered building control approver signs it off. Keep that certificate with the house deeds; a buyer's solicitor is likely to ask for it. Alongside it goes our 10-year workmanship guarantee in writing, and the guarantee page sets out what it covers and how to use it, so file the two together.

Signs a unit has reached the end

Misting between the panes is the clearest: the seal in the double glazing has broken down, moisture has got in, and no amount of wiping on either side will shift it. Other signs are draughts around the frame, a sash that no longer closes tight, timber that has gone soft or dark along the bottom rail, cracked or crazed plastic on an old dome, and water stains on the reveal after heavy rain. Single-skin domes and older plastic rooflights also lose heat quickly and drip with condensation in winter, even when nothing is broken.

Replacing a roof window

Size comes up before anything else. Older roof windows were often made to standard size codes. In a VELUX code such as MK04, the letters give the width and the digits the height, so a matching replacement can often go into the same opening with new flashings and little disturbance to the ceiling inside. Where the old window is an unusual size, the opening is adjusted and the lining made good. Either way the new frame gets fresh flashings, matched to the window they seal and to the tiles or slates around it.

Replacing a flat rooflight or lantern

For a flat rooflight, the kerb matters as much as the glass. We check whether the upstand is sound, tall enough to keep water off the glass edge, and insulated. If it is, a new rooflight can be sized to it. If it isn't, the kerb is rebuilt and the roof covering dressed back up it. Swapping a tired plastic dome for a double- or triple-glazed flat glass unit is a sensible upgrade on an older extension: quieter in the rain, warmer in winter and clearer to look through.

Lanterns are judged frame by frame. Sometimes the glazed units alone can be changed; a lantern whose frame has failed is better replaced whole, on a kerb checked at the same time.

The rules still apply

A replacement roof window or rooflight has to meet Part L: 1.4 W/m²K (or Window Energy Rating band B) for a roof window and 2.2 W/m²K for a rooflight or roof lantern, which is usually a step up on an older unit. A like-for-like swap on a house seldom raises planning questions, though a listed building is another matter. Our misted rooflights service covers the glass-only route, and what it costs to replace a rooflight explains what moves the figure.

Do you need planning permission?

For a house in England, rooflights and roof windows are usually permitted development under Class C. That holds if the window sticks out no more than 150 mm beyond the plane of the original roof slope, frame included, sits no higher than the highest part of the original roof, and any window on a slope forming a side elevation is obscure-glazed and non-opening unless the opening parts are more than 1.7 m above the floor of the room it serves. A roof window fitted in the plane of the slope normally stays inside the 150 mm limit.

Flats and maisonettes have no householder permitted development rights. Nor do houses created by converting offices, shops, barns and similar buildings under change-of-use rights. A conservation area does not remove Class C by itself; an Article 4 direction does. A listed house keeps its Class C rights, but a new or altered roof window will almost always need listed building consent as well. Rights can also have been taken away by a condition on an earlier planning permission, so newer and extended houses need their history checked. On a flat roof, a lantern will usually clear the surface by more than 150 mm, which normally puts it outside Class C, and a planning application is the expected route unless the council says it is not required.

Where your house stands on each of these points is checked at survey; the decision on any application belongs to the council. The detail is in our guide to skylight planning permission, and the government's householder guidance sits on the Planning Portal.

Building Regulations and Part L

Making a fresh hole in a roof counts as building work, and our skylight Building Regulations guide takes each requirement in turn. The structure has to carry the loads around the opening, the new glazing has to meet Part L for energy, and fire and escape rules come in where they apply. For existing homes, Part L 2021 sets a limit of 1.4 W/m²K for a new or replacement roof window, or Window Energy Rating band B, and 2.2 W/m²K for a rooflight or roof lantern.

Either the local authority or a registered building control approver checks and signs the work off. Building Regulations set no daylight requirement for houses in England. They govern how a rooflight is built and how well it holds heat, and leave the amount of light to you.

Escape from rooms in the roof

In a bungalow or chalet bungalow, a roof window can serve as the escape window for a room in the roof, provided the opening is at least 0.33 m² and at least 450 mm wide and 450 mm high, the bottom of the opening is no more than 1,100 mm above the floor, and the window stays open without being held. Converting the loft of a house with two floors is a different case. It creates a storey more than 4.5 m above ground level, which normally needs a protected escape route down the stairs, and a roof window in the loft is not accepted as the way out.

What a U-value measures

A U-value measures how quickly heat passes through part of a building. It is written in watts per square metre per degree of temperature difference, W/m²K, and lower is better. An old single-skin dome loses heat fast, which is why its inside face streams with condensation on a cold morning. Modern double-glazed units with a low-emissivity coating and gas-filled cavity do far better, and triple glazing better again, which is what an upgrade to energy efficient rooflights puts in. The figure that counts is for the whole unit, frame included, because a good pane in a cold frame still leaks heat at the edges.

Glazing affects summer comfort as well. Solar control coatings cut the heat coming through a south-facing rooflight while keeping the room bright. Self-cleaning outer coatings help a flat rooflight shed dirt when it rains. On a walk-on unit or anything low enough to be knocked, the inner pane is laminated safety glass. Each of these choices goes into the written quote, so you know exactly what is being fitted.

Insulation around the opening

The kerb on a flat roof and the lining around a roof window both need insulation, or the reveal becomes a cold strip where condensation forms and paint flakes. We insulate the upstand and the reveal as part of the job, and fit vapour control and underlay collars around the window so warm, damp room air stays out of the roof timbers.

Flashings for Kent roofs

Clay peg tiles and plain tiles cover many older cottages and farmhouses, Welsh slate tops Victorian terraces, and concrete interlocking tiles sit on post-war estates. Each needs its own flashing. Plain and peg tiles are small and laid steep, so the flashing has to work with soakers and the tile courses around the frame. Slate is thin and flat, so slate flashings sit low and tight. Interlocking tiles have deep profiles, and the flashing apron is shaped to follow them. Get the detail wrong and a roof window can let water in around its frame.

Flat roofs have their own details. Felt, single-ply membranes and liquid coatings each turn up a kerb differently, and the upstand must stand high enough above the finished roof to keep standing water off the glass edge. On a slate or peg tile slope where a low profile matters, we fit conservation rooflights with flashings chosen for that covering.

Installing a new rooflight

A new opening involves more work than a swap. The roof covering is stripped and remade, timbers are trimmed, and the inside is lined and plastered. On a flat roof a kerb is built and the waterproofing dressed up it. Larger units can need extra structural timber, and a lantern needs the most carpentry of all. The product itself varies with size, glazing, opening type and whether it is made to measure, and our costs guide shows how those lines build into a quote.

Replacing a rooflight

Replacement tends to be simpler when the new unit matches the old size code or the kerb is sound. The price climbs when the opening has to change, the kerb has rotted, or the old flashing cannot be reused with the new frame. Our answer on the cost to replace a rooflight sets those differences out.

Access and finishing

A single-storey extension roof can often be reached with ladders and a tower. A roof window high on a three-storey town house may need scaffolding, which is a cost of its own. Inside, the amount of making good counts: plastering the reveal, redecorating the ceiling, or rebuilding a damaged section of plasterboard. Blinds, electric operation and rain sensors add to the price, and so does toughened or laminated security glass.

Is there a cheaper alternative to VELUX?

VELUX is one manufacturer among several. Other ranges make roof windows to similar size codes and to the same Part L limits, and some cost less. We can quote more than one option from the manufacturer ranges we fit and explain where they differ, in glazing, finish and flashing. For a dark hallway, a sun tunnel can cost less than a roof window altogether, because the openings it needs in the roof and the ceiling are both small.

Towns and villages we cover

Close to home, we work in Bearsted, Coxheath, Aylesford and Larkfield, and out to West Malling, Kings Hill and Staplehurst. Further out we cover the Medway towns, including Chatham and Rochester, along with Tonbridge, Sittingbourne and Royal Tunbridge Wells. The full list is on our areas page, with a page for each town.

Which council looks at your roof

The planning authority changes with the address. A home in the borough goes to Maidstone Borough Council for any planning question, while Tonbridge falls under Tonbridge and Malling Borough Council. Article 4 directions apply in some places and take away rights a house would otherwise have, so the council's records for your street are part of what we check.

Our work is in people's homes, from a single roof window in a loft to a lantern over a garden room. So the questions at survey are about how you live in the room: where the table goes, which way the bed faces, whether you want fresh air as well as light, whether the space is used in the morning or the evening. A bedroom used mostly at night may suit a roof window with a blackout blind; a home office in the eaves may want an opening sash within reach of the desk.

Starting a conversation

The quickest way to begin is a WhatsApp message to 07880 284133. You can also email info@orchardskylightsmaidstone.co.uk or fill in the quote form below. We will arrange the survey at a time that suits you.