Skylight and rooflight fitting in Pontlliw

Pontlliw is a village near Pontarddulais, off Junction 47 of the M4. The Welsh spelling splits it as Pont-lliw. The name takes its first half from the bridge and its second from the River Lliw, which flows through the village.

The village sits among semi-rural surroundings, with the M4 close enough to make the commute easy. That mix of houses and open ground means the weather arrives with little to break it, and exposed glass is where it shows.

The roots go back to 1740, when the Lliw Forge was in operation. The village population began to grow as a result, and new churches and chapels were built. Pontlliw still has one active chapel, Carmel Baptist, which runs activities through the week in both Welsh and English. By the 19th century the village was a mere collection of a few houses, and more were built throughout the place afterwards. In 2011 about 1,645 people lived in the village.

Names in the village record its layers. A bridge gave the first part of the name, and a forge gave the village its reason to grow. Chapels came next, then houses, then the motorway. Each stage left a different type of roof behind it.

A railway line runs through Pontlliw, but there is no station. One did operate briefly, between 1923 and 1924. Public transport is thin, which makes the car the usual way of getting about, and the motorway junction nearby keeps the village close to everything else.

A village that grew by additions has roofs of several ages. A rear extension from the last few decades, a lean-to on an older cottage and a loft room under original slates are three different jobs for a rooflight, and a visit shows which one you have.

The road to Swansea is 6.82 miles long, and Pontlliw lies north-west of the city. Nearby are Tircoed and Penllergaer, where we also fit and replace rooflights.

The City and County of Swansea Council is where a Pontlliw rooflight application is sent, and Pontlliw falls outside the Gower AONB. For the permitted development conditions that a house has to meet for a rooflight, the guide to planning permission in Wales is where to look.

The Welsh Government's page on planning permission for roof alterations gives the plain-language outline, and it is useful to read before you call anyone.

Three situations sit outside those conditions. Flats and maisonettes were left out of householder rights from the start. Two things can strip a house of them: an Article 4 direction from the council, or a clause written into its original planning approval. And a listed building, wherever it is, needs listed building consent for a rooflight that changes its special architectural or historic character, which is applied for through the council as local planning authority.

If you are not sure which situation applies, ask before ordering anything. Council planners will tell you what they think, and a Lawful Development Certificate is how the council certifies it in writing.

Building Regulations deal with how the work is built, which is not the planning question. There are two kinds of building control body, the council's building control service and a registered building control approver, and you are free to choose which one handles the project. Notifiable work includes a Building Regulations notification, which we file with whichever body you choose.

Replacements follow slightly different logic from new openings. Swapping a roof window for another in the same place is still building work, and the new one should reach 1.4 W/m²K or Window Energy Rating Band B under Approved Document L (Wales). Swapping just the glass and keeping the frame falls outside the energy rules. A new rooflight is different, since it will generally need approval, with the roof structure checked and its weight carried.

Glass safety has its own document in Wales, Approved Document N. It deals with glazing in critical locations, which means glass in walls and partitions up to 800 mm above the floor, and up to 1,500 mm in or beside a door. Where a loft conversion puts a window low in a wall, it is relevant.

Start with the loft. A roof window in a converted loft carries both air and light, and the two ways of hanging the sash suit different people. A top-hung window opens up and out over your head. A centre-pivot turns right over, so the outside glass can be cleaned from within. Electric opening suits a window out of reach, and the VELUX solar and electric models can close themselves with an integrated rain sensor.

A loft conversion in an existing two-storey house also brings fire rules about the stairs and the escape route. Those are set out in Approved Document B (Wales), on the Welsh Government's fire safety guidance, and the survey is the point to check them against your own staircase.

On the back of a kitchen, a flat roof rooflight gives daylight over the worktop. Its limit is 2.2 W/m²K, and that figure is based on the whole developed surface area of the unit, which is often bigger than the opening cut in the roof. Where height and shape are wanted, a roof lantern stands on an upstand. A lantern is not given the 2.2 figure here, and one on a new extension is an item to raise with the council.

For an extension that adds a lot of glass, the energy rules count the total. When an opening is enlarged or a new one made, windows and doors together are limited as a share of the floor area in the 2022 edition. The next Welsh edition, from 4 March 2027, names roof windows and rooflights in that sum and lets the total rise if the home's energy performance is improved to make up for it.

A bathroom wants the least cold glass and the most air movement. A roof window with a fan that runs on is the dependable pair, and a sun tunnel is a second route where the roof above is clear and the room has no outside wall.

Opening a window high in a roof raises the question of how much of it you need open. Every bedroom or living room has to be capable of rapid airing, and an opening roof window can provide it where the sash opens far enough for its size. Approved Document F (Wales) sets out the arithmetic, so a small fixed rooflight does not count towards it.

Sometimes the window is already there and has failed. Fogging between panes usually means the sealed unit has lost its seal, and misted rooflights are part of what we replace as well as the new openings we cut.

No figure is named before the survey, which costs nothing. A fixed written quote follows it, and the job closes with a 10-year workmanship guarantee, given in writing. Telephone 01792 929062 or ask for a survey online.