Skylights & rooflights in Brighton & Hove

The top storey of a Brighton terrace is often a mansard: a steep lower slope, usually slated, with a shallow upper slope above it that you cannot see from the street. Dormers were the old answer to lighting that room. A roof window is the lighter answer. It sits in the slope itself, in line with the slates, and it gives you sky rather than a view of the house opposite.

A roof window is the trade name for an opening window made for a pitched roof. VELUX is the familiar name, and a VELUX roof window is a common choice for lofts and mansard rooms, though other makers build windows to the same standard and we will quote on those where the brief suits. The window arrives as a unit with its own frame, its own flashing kit for slate or tile, and a lining that ties it into the plaster inside.

Which type of roof window suits a mansard room

The first question is the pitch. A mansard's lower slope is steep, close to a wall, and its upper slope can be quite flat. Every roof window has a range of pitches its maker allows, and the survey checks your slope against it before anything is ordered.

Size comes next. VELUX gives each size a code such as MK04. The letter is the width and the digits are the height, so an MK06 is the same width as an MK04 but taller.

Blinds, escape and the loft below

Ask about the blind when you choose the window, not after. Each one clips into the frame of the window it was made for.

If an older window has a blind that has failed, a replacement blind can often be matched to the window's code, which is printed on the data plate inside the frame.

People often ask whether a roof window can be their fire escape. Under Approved Document B, an escape window only counts for a storey within about 4.5 m of the ground. That works in a bungalow or a chalet bungalow. It does not work in a loft conversion on a two-storey house, let alone a four-storey terrace: there the escape route is a protected stair, and the roof window is for light and air. We would rather say so at the survey than have you plan a room around a window that cannot do that job.

Inside, the loft behind the plaster matters as much as the window. The lining around a new roof window needs insulation packed to the frame so the reveal does not become a cold spot that gathers condensation. On an older loft room with thin insulation, we will tell you what we find when the opening is cut. More on the window range is on the roof windows page, and the maker's own range is covered on the VELUX windows page.

Behind many Brighton and Hove terraces runs a back addition: a narrower wing that holds the kitchen or a bathroom, often with a flat roof at first-floor level. The room underneath is usually the darkest in the house, lit by one window onto a side return that sees little sun. A flat rooflight in that roof is the simplest way to change it.

A rooflight is the trade word for glazing in a flat or near-flat roof. It differs from a roof window in one important way: it does not sit in the roof plane.

Kerbs, upstands and flashing on a flat roof

On a flat roof, the weak point of a rooflight is the edge, not the glass. The kerb, or upstand, is the timber or insulated frame that lifts the rooflight off the deck. The roof covering, whether that is felt, EPDM rubber or GRP fibreglass, has to turn up the face of the kerb and be sealed under the rooflight's own frame. If the upstand is too low, or the covering stops short, water finds the joint in the first hard south-westerly.

So we build the kerb high enough to sit above the finished roof with room to spare, insulate it so it is not a cold bridge, and dress the covering up and over it. On an older felt roof the covering around the opening is often tired, and the survey says plainly if the roof itself needs work before a rooflight goes in. The glass unit sits on the kerb with a slight fall, even on a dead-flat roof, so the pane sheds water instead of holding a puddle.

Fixed, opening or walk-on

Each one is covered in more detail on the flat roof rooflights and walk-on rooflights pages.

For energy, the Building Regulations set a limit for a new or replacement flat rooflight of 2.2 W/m²K. Energy efficiency has moved on a long way since the old plastic domes: modern double and triple glazed units meet it comfortably, and the better ones go well past it.

When a kitchen is extended into the garden, the new flat roof is the obvious place for a roof lantern. A lantern is a pitched glass roof in miniature, standing on a kerb in the middle of a flat roof: a ridge, sloping glazed sides and hipped ends. Where a flat rooflight gives you a clean square of sky, a lantern gives height. The ceiling seems to lift, and the light comes in from several directions through the day.

A lantern needs a roof that can carry it.

Frame materials and colour

Aluminium is the usual frame for a modern lantern. It is slim, strong and stable, so the glazing bars can be narrow and the glass does the work.

Near the seafront, the finish matters. Salt in the air is hard on any metal coating, so ask about the coating's specification if your house faces the sea, and rinse the frame with fresh water now and then. Gulls can be tough on seals and gaskets too, which is one more reason to look at the kerb and the beads when you look at the glass.

Glass, heat and glare

A south-facing lantern over a kitchen can make the room hot on a summer afternoon. The glass is where that is managed. Solar control coatings reflect a share of the sun's heat while still letting light through, and a self-cleaning outer pane breaks down dirt so rain can rinse it away. The same 2.2 W/m²K energy limit applies to a lantern as to a flat rooflight. Inside, a lantern can be fitted with blinds, though on the hipped ends they are made to measure. You will find the options laid out on the roof lanterns page, and the glass specifications on the energy efficient rooflights page.

Some rooms cannot have a rooflight because there is another floor between them and the roof. The middle landing of a tall terrace is the classic case: no window, a stair that drops away in shadow, and a light switch on all day. A sun tunnel solves that without opening up the ceiling of the room above.

A sun tunnel has three parts, and the light takes them in order.

Where a sun tunnel works and where it does not

On a slate roof the dome sits on a flashing plate that tucks under the slates above and over those below, like any other roof penetration. On a flat roof it sits on a kerb. Fitting takes a fraction of the work of a full rooflight, but it still involves the roof, so the question of access in the next sheet applies just as much. There is more on sizes and routes on the sun tunnels page.

The glass is rarely the hard part of a rooflight in this city. Getting to the roof is. A four-storey terrace with a basement area at the front, a steep street and a controlled parking zone outside is a different job from a bungalow with a drive. This is the part of the work we plan first, and it is the reason every Coastlight quote includes the access plan: a written page that says how we will reach your roof, what permissions that needs, who applies for each, and what it costs.

The route to the roof

Licences from the council

Scaffold on a pavement or road needs a licence from the highway authority, which in the city is Brighton & Hove City Council and further out is East Sussex County Council, West Sussex County Council or, just over the Surrey line, Surrey County Council. If the scaffold lorry, a skip or a glass delivery needs space on a street where parking is by permit, a parking bay suspension may be needed as well. We apply for both. The time a licence takes affects the start date, so the access plan sets out the order of events: licence, scaffold, roof work, strike. The guide on scaffold licences and parking suspensions goes through the process.

The freeholder and the neighbours

Many of the city's tall houses are now flats. If you own the top-floor flat, the roof above you is usually not yours. It normally belongs to the freeholder, and the lease usually says you need their written consent, called a licence for alterations, before you change it. Check your lease, and ask your managing agent early, because that consent can take longer than the work. The access plan names whether it is needed and who you should ask. The guide to rooflights in flats and leasehold buildings covers it in more depth.

The people below and next door also need to know. A scaffold outside their window, a skip in the street and noise on the roof are easier to live with when someone has told you, in writing and in advance, what is happening and for how long. We give that notice as part of the job.

Every sheet so far has been about the roof. This one is about the room. Glass in a roof gives a room light from above, which behaves differently from light through a wall. A window in a wall lights the floor near it and leaves the back of the room dim. Light from overhead falls into the middle of the room and reaches the corners. That is why a rooflight of a modest size can do more for a deep kitchen than a much bigger window at one end.

Why daylight from above changes a room

Natural light from the sky is softer and more even than sunlight through a side window, because it comes from the whole dome of the sky rather than one bright patch. Where you want to add natural light to a room you use all day, think about which way the slope faces as much as how big the glass is.

It also changes how a house is used. A dark landing becomes a place you can read the post. A loft room with a roof window over the desk becomes somewhere you would choose to work. A kitchen with a lantern over the table no longer needs the lights on at lunchtime.

Opening rooflights, ventilation and electric controls

Light is half of it. Air is the other half. A roof window or an opening rooflight at the top of the house lets warm, damp air out at the highest point, and that is often the best ventilation a tall house can have. Open one at the top of the stair and a window at the bottom, and the house draws a breeze up through itself on a warm evening.

Where the glass is out of reach, an electric motor opens it.

The details are on the electric and opening rooflights page.

Not every call is for new glass in a new opening. Plenty of calls are for rooflight replacement in Brighton and Hove: an old roof window that has misted between the panes, a plastic dome that has gone yellow and brittle, a flat rooflight that drips at the corner every winter. The opening is already there. The question is what has failed, and whether the answer is a new pane, a new unit, or more.

Replace the glass or the whole unit?

Misting inside a double glazed unit means the seal around the edge of the unit has failed and moist air has got into the gap between the panes. That is not something a repair can cure: once the seal has gone, the gap will keep fogging. If the frame around it is sound, the sealed unit is changed for a new one. If the frame itself is rotten, warped or leaking, or the window is old enough that its parts are no longer made, a whole new unit is the right answer. The same goes for a cracked or crazed dome. Our page on misted and failed rooflights goes into the signs, and the short answer page on the signs a rooflight needs replacing lists what to look for from inside.

Like for like is still building work

This catches people out. Swapping a whole rooflight or roof window, even for an identical one in the same hole, counts as building work. It is notifiable, and the new unit has to meet the current Part L energy limits. Changing only the glass in a sound frame does not. Either way, we tell you which route your job takes, and where it is notifiable we handle the notification. For a VELUX window replacement, skylight replacement in Brighton and Hove on an old VELUX is often a tidy job.

Maintenance and lifespan

A well fitted rooflight asks for little. Clear leaves and gull debris from the kerb and the gutter below it in autumn. Wash the glass with plain water and a soft brush, and avoid anything abrasive on a self-cleaning pane. Clean the filter in the vent of a roof window when it gets dusty, and run an electric unit open and shut now and then so it does not stick. Simple maintenance like this keeps seals and gaskets working, and a unit treated this way will last for many years. When the seal finally goes, the glass can be changed without disturbing the roof.

Two separate sets of rules apply to glass in a roof. Planning decides whether you can change the look of the building. Building Regulations decide whether the work is safe, sound and energy efficient. A job can need one, both or neither, and the access plan says which.

Planning permission for a house

For a house, rooflights usually fall under permitted development, which means no planning application is needed, as long as some conditions are met.

Brighton & Hove City Council has Article 4 directions in many of its conservation areas. An Article 4 direction can take away these permitted development rights, so in parts of the city a front-facing rooflight that would be fine elsewhere needs an application. A conservation rooflight, with slim steel-look bars and a low profile in the slates, is the type planners most often expect to see on a period roof.

If the building is listed, listed building consent is needed for any change that affects its character, and that is in addition to planning. Inside the South Downs National Park, the South Downs National Park Authority is the planning authority, though the district council still runs Building Control.

Flats need an application

Flats have no permitted development rights for rooflights. A new rooflight in the roof of a building divided into flats needs planning permission, as well as the freeholder's consent covered earlier. The guide to planning permission for rooflights in Brighton & Hove takes each case in turn.

Building Regulations and the notification

Cutting a new opening in a roof is building work. Building Control looks at the structure, which means how rafters or joists are trimmed around the hole, the weathering, the fire performance and the energy rating.

The notification goes either to the local authority, as a building notice or a full plans application, or to a registered building control approver, the private route. We handle the Building Control notification where the work is notifiable, and the completion certificate comes to you at the end. More detail is in the guide to Building Regulations for skylights and rooflights.

We do not publish prices for skylight installation in Brighton, because a rooflight in this city is rarely just the unit. Two identical windows can cost very different amounts to fit depending on where they go. The survey is free, and what follows it is a fixed written quote with the access plan inside, so you see the whole figure before you commit. The costs page explains how a quote is built.

The things that change the cost

Every one of these is set out separately in the quote, so you can see where the money goes.

How an installation runs, step by step

Every skylight installation in Brighton and the towns around follows one order. Whether it is a single roof window installation in a loft or a lantern over a new kitchen, the steps do not change.

Inside, there is dust while the ceiling or the plaster is opened. We sheet the floors and the stair, and keep the room covered until the glass is in. The how long does it take to fit a skylight page covers timings, and our guarantee page sets out the 10-year workmanship guarantee that covers the installation.

We cover Brighton and Hove and every town within 30 miles by road. Rooflight installation in Brighton and Hove makes up much of the work, but the same survey, written quote and access plan apply wherever you are. The highway authority for the scaffold licence depends on where you are.

Within the city

Across the city, from the Regency terraces to the suburbs that climb the Downs, including Patcham, Portslade and Rottingdean.

Towns and villages in East Sussex

Telscombe Cliffs, Peacehaven, Newhaven, Seaford, Lewes, Ringmer, East Dean, Polegate, Willingdon, Eastbourne, Stone Cross, Westham, Pevensey Bay, Hailsham, Hellingly, Horam, Heathfield, Uckfield, Buxted, Newick, Mayfield, Crowborough and Forest Row.

Towns and villages in West Sussex

Southwick, Shoreham-by-Sea, Lancing, Sompting, Worthing, Findon, Ferring, East Preston, Angmering, Rustington, Littlehampton, Arundel, Yapton, Barnham, Middleton-on-Sea, Felpham, Bognor Regis, Tangmere, Upper Beeding, Steyning, Henfield, Partridge Green, Ashington, Storrington, West Chiltington, Pulborough, Petworth, Billingshurst, Southwater, Broadbridge Heath, Horsham, Hassocks, Hurstpierpoint, Burgess Hill, Cuckfield, Haywards Heath, Lindfield, Ardingly, Pease Pottage, Crawley, Crawley Down, Copthorne, Ashurst Wood and East Grinstead.

Just over the Surrey line

Felbridge, Smallfield and Horley are inside the 30 miles too.