Rooflights and skylights fitted in Llangennech

On the map, Llangennech sits in Carmarthenshire as a village, with the Afon Morlais running through it. Otters, hedgehogs, grass snakes, common lizards and adders have all been recorded there. The Heart of Wales line serves it, with trains between Swansea and Shrewsbury.

Coal shaped the village. Llangennech was a coal mining community with several local collieries working steam coal, and a large Labour tradition grew up among the mine workers. A large Royal Navy depot stood here until 2007, when it closed in a Ministry of Defence restructuring. Earlier still, between 1801 and 1803, the Llangennech Estate was assembled across around 4,000 acres.

A drive of about 10 miles from Swansea, heading north-west, brings you here, which is well inside our 30-mile radius, and our fitting work reaches Bryn, Hendy and Loughor too.

Roofs of different ages and shapes take different glass, and we treat none as typical. What matters on any of them is the opening: whether one exists already, what size it is and what condition it is in.

If a window is there, its size code gives you a head start, and if it is not, the roof shape tells us which kind of new opening makes sense. A pitched slope with a loft room beneath it has a different list of options from a flat extension roof, and a landing with no spare roof space above it has a third.

None of that can be settled from the street. The roof itself decides the details, so the survey has to come ahead of any figure.

Planning in Llangennech is handled by Carmarthenshire County Council, so a rooflight or roof window in a new position is a matter for its planning team. The village lies beyond the Gower AONB boundary. Which houses can go ahead without an application is a question of listed conditions, set out in our Welsh planning guide, and the address decides the answer.

Householder rights were never available to flats and maisonettes. For a house they can be taken away: a council can do it for a whole area by direction under Article 4, and the conditions on an old planning consent can do it for a single property. Listed houses answer to a separate regime, listed building consent, which since November 2024 rests on the Historic Environment (Wales) Act 2023. Cadw is the Welsh Government's historic environment service. Consent covers work inside a listed house as well as outside, including fixtures and fittings, and even minor work can need it. A listed owner who starts before consent arrives risks a criminal charge, so the council comes first.

The Building Regulations count a window swap as building work in its own right, even where the opening stays as it was. Making a fresh hole in a slope brings approval into play for different reasons: forming it usually alters the roof's structure, and the roof has to cope with the extra load. Where the work is notifiable we handle the Building Regulations notification, using local authority building control or a registered building control approver. You choose between the two.

Oversight differs between them. The Building Safety Regulator oversees the private approvers, while local authority building control answers to the Welsh Ministers.

Energy limits arrive with any replacement. The table gives the two figures that matter in Wales, set by Approved Document L (Wales) for existing homes. A newer Welsh edition of that document takes effect on 4 March 2027, and its values for these units are the same.

Swing the old sash open and check its upper rim. VELUX fixes a metal plate there, called the type sign, and the company says each of its windows built after 1968 carries one. A code such as MK04 or UK04 is printed on it and stands for a width and a height. VELUX lists MK04 as 78 by 98 cm, MK06 as 78 by 118 cm and UK04 as 134 by 98 cm, so a code can be matched to a real opening in a moment.

Matching the size is the simple route, and it suits an opening that is sound. If the rafters around the old window were framed well, a same-size swap leaves them alone. If the room wants more light, a bigger unit means a bigger opening, and that pulls the roof structure into the discussion. Our size codes explained page shows how the codes work, and like-for-like VELUX swaps covers the swap itself.

Ventilation comes along with the swap. Suppose the old window had no trickle vents. Where a house relies on natural ventilation, the guidance accepts new vents with 8,000 mm² of equivalent area in a living space or kitchen, and 4,000 mm² in a bathroom, as one way of showing the room breathes no worse. Approved Document F (Wales) sets those sizes. If those sizes are out of reach in practice, the vents go as near to them as the window allows.

Cloudy glass between the panes is a different job. The glass may be changed on its own, or the whole unit may go. Read about misted rooflights before deciding, and about roof windows generally if the old one is a poor fit for the room anyway.

A room with no roof window at all is a separate case, and a dark landing is the obvious one. A sun tunnel suits it, provided the dome on the roof has a clear run down to the ceiling.

Costs depend on those choices, which is why none is quoted here. A same-size swap in a sound opening and a larger window in a new one are different jobs, and a misted unit sits somewhere between them. Our costs page has more on costs, and the free survey turns that into a figure for your roof.

The first visit costs nothing, and a fixed written quote follows it. When the work is finished, a 10-year workmanship guarantee goes into writing. To arrange it, ring 01792 929062 or use the booking form.