Skylights and rooflights in Abergwynfi

Abergwynfi is a village in the Welsh county borough of Neath Port Talbot, in the community of Gwynfi and Croeserw. It is one of two villages, with Blaengwynfi, and the two were mainly built between 1892 and 1893 following the construction of the Swansea Bay Railway.

The names mean "Mouth of the Gwynfi" and "Source of the Gwynfi" respectively, the Gwynfi being the rather short river that separates the two. The pair were once marketed as "The Cape of Good Hope", in the years when coal mining mattered a great deal to the valleys.

Abergwynfi is located within the Afan Forest Park, which is a mountain bike centre.

Abergwynfi lies east of Swansea at a little under 20 miles on the road, comfortably inside the 30-mile ring we work in. Croeserw and Glyncorrwg are the neighbours we also look after.

Our records say very little about the houses here, so we say very little. What we can say is how a rooflight behaves, and what a survey looks for: the pitch and covering of the roof, the room below, and whether the glass already there has reached the end of its life.

A village mainly built between 1892 and 1893 had most of its roofs put on over a short span. That does not tell us how any one of them has been repaired since, so it is the survey, not the date, that counts.

On a survey of an older roof we check the covering first. Slates that have slipped, tiles that have cracked and a ridge in poor repair all affect where a window can go and how its flashing is dressed. It is cheaper to find that out before a hole is cut than after, and a free survey exists for exactly that reason.

The loft comes next. A clear space with a good height suits a window with a view; a cramped one with a water tank in the way points to a different answer. The timber under the covering matters too, because an opening can interrupt rafters, and the rafters decide how wide a window can be.

Where a house is one of a row, ask the neighbours what they chose. A row of matching windows on one slope looks tidy from the street, and it can save you from picking a size nobody else on the row uses. The survey does not depend on that, but it is a useful starting point.

Planning matters in Abergwynfi go to Neath Port Talbot Council, and the council can say what applies to a given house. Gower's AONB lies elsewhere. Abergwynfi's built-up area numbered 818 people in the 2021 Census, and the Gwynfi, a rather short river, separates it from Blaengwynfi.

On unprotected land a house may take a rooflight as permitted development, provided it stays inside the limits in the Wales planning guide. A flat or maisonette starts with no householder rights at all, and a council can withdraw a house's rights through a direction or a condition on its first consent.

Building work rules matter when old units are swapped. Replacing a window or roof window like for like is building work, while a repair is not. Re-glazing within the frame already there stays outside what the energy rules treat as building work. Where a whole unit is replaced, the new roof window should reach 1.4 W/m²K or Window Energy Rating Band B, and the new rooflight 2.2 W/m²K, under Approved Document L (Wales).

A historic or character house has one extra allowance. A replacement roof window that cannot reach 1.4 can fall back to 1.2 W/m²K at the centre of the pane, or to low-e secondary glazing. Rooflights get no such allowance.

A private building control firm in Wales must be registered as a registered building control approver, and you may choose it or the council service. A brand-new opening generally needs approval, and for notifiable work the paperwork to building control is ours to send.

Listed buildings follow their own route, through listed building consent from the local planning authority with Cadw consulted. We hold no listing information for the village, so ask the council about any particular house.

You can tell a lot from the ground. A cloudy pane normally means a failed seal. A frame that drips on cold mornings and stays dry in a downpour is condensing. A frame that drips only while it rains is a flashing or kerb problem. Those are three different jobs, and the survey sorts out which you have.

When the seal has failed, we replace misted rooflights, and the swap can bring better glass in the same opening. The size is readable from the old unit. On a VELUX, the metal plate along the top of the sash carries a code, which tells you the width and the height.

A more efficient rooflight is worth asking about while you are replacing. The figure to meet is in Approved Document L (Wales), and glass choices such as double or triple glazing, coatings and warm edges move a unit towards it.

If the old unit was a fixed pane in a slope, think about whether it should open. A room that steams wants air to leave. Electric opening rooflights suit glass out of reach, and the same page covers the rain sensor.

On a flat roof, an old rooflight may just need its kerb and fall reconsidered when the new one goes in. See flat roof rooflights.

A free survey comes first. The fixed written quote follows it, and our 10-year workmanship guarantee comes in writing. Phone 01792 929062 or book a survey.

Whichever way the job goes, the flashing or kerb has to suit the covering around it. The guarantee we put in writing is on the workmanship of that fitting.

Keep the old size when the roof allows. A unit of the same size goes into the existing opening, whereas a larger one usually means cutting into the rafters, and that changes both the survey and the Building Regulations question. Say early if you want more light than the old window gave, and the survey can weigh the two.