Skylight and rooflight fitting in Brynamman

Brynamman (Welsh: Brynaman) is a village beneath the Black Mountain, Y Mynydd Du, which forms part of Bannau Brycheiniog National Park, also known as the Brecon Beacons. The River Amman divides it into Upper Brynamman and Lower Brynamman, and the same river is the boundary between Carmarthenshire and Neath Port Talbot, in the old county of Glamorganshire.

Brynamman had 2,608 residents at the 2011 census, and the urban area that includes Gwaun-Cae-Gurwen had 5,692. Remains on the mountain, from stone dwellings that may be prehistoric to an early lime kiln and rectangular medieval buildings, show people have lived around here for a very long time.

Meadows in the area now support some scarce flowers, Whorled Caraway and Meadow Thistle among them, and wildlife such as the marsh fritillary butterfly and dormice. That is local colour, and for a homeowner the practical point is the damp ground and the water that comes with it. A house in a village with this much standing water around it benefits from a roof that sheds its share quickly.

George Borrow described aspects of Gwter Fawr in the mid-19th century in his book Wild Wales, published in 1862. In more recent times the Brynamman Lido, which opened in 1934 and closed in 2010, has been the subject of a feasibility study into reopening it.

From Swansea the road distance is 16.09 miles, with the village to the north, which keeps it within our 30 road miles. Gwaun-Cae-Gurwen and Garnant sit close at hand.

The river decides more than the shape of the village. A house on the Carmarthenshire bank belongs to Carmarthenshire County Council for planning, and one on the far bank belongs to Neath Port Talbot Council. Which side of the water an address lies on is therefore the first thing to establish, and a quick check with either council will settle it. A postal address can mislead, since a village divided by a river may share one name between two counties, so the exact address, and not the street name, settles which council applies.

The Black Mountain above is part of Bannau Brycheiniog National Park, and the Park Authority is the planning authority for land inside the park. In Wales, a rooflight added to a house on land inside a National Park is not permitted development and needs a planning application. Whether a particular house lies inside the park boundary is a question for its exact address, and the park authority or the council can answer it.

Doubt about any of this has a formal remedy. The council can grant a Lawful Development Certificate, which records in writing that a proposed rooflight is lawful without an application. It adds a step at the start and leaves a document to hand over if the house is sold, and it answers questions that guesswork cannot, for instance whether an old condition or a direction applies.

For houses outside any protected land, the Welsh planning guide sets out the conditions that apply. Nobody in a flat or maisonette holds householder rights, and councils may withdraw them from houses through an Article 4 direction. Listed buildings need listed building consent for work affecting their character, and Cadw explains the process.

One more local point: Cadw describes itself as the Welsh Government's historic environment service, and it publishes each listed building record in Cof Cymru. A listed house needs consent for a rooflight that would affect its character, and Cadw notes that even minor work can need it.

Building control is the second decision. A new rooflight generally needs approval, and you may choose the council's building control service or a registered approver. We make the notification when the work is notifiable.

In a loft bedroom, the roof window that suits is the one that copes when nobody is home. VELUX solar and electric roof windows carry an integrated rain sensor, and it shuts the window when rain starts. For a household that is out all day, that is a comfort. See the electric opening rooflights page for how they are powered and controlled.

Under a flat-roofed kitchen extension, the glass of choice is a rooflight set on a kerb. Approved Document L (Wales) defines a rooflight as a glazed unit set on a kerb or upstand and gives 2.2 W/m²K for a new or replacement one in an existing home. For a roof lantern the council has the last word, so we put the question to it, and our roof lanterns page explains the product.

An older loft window can be matched with some detective work. VELUX fixes a type sign carrying the size code to every window made after 1968, and the code gives the width and height, so a replacement of the same size is a matter of reading the label with the sash open. The new unit should reach 1.4 W/m²K or Window Energy Rating Band B under Approved Document L (Wales). Swapping like for like counts as building work, and fitting a new unit does too.

Ventilation is part of that conversation. Approved Document F (Wales) wants the home no worse ventilated after a window is replaced, so trickle vents on the old unit become vents on the new one, no smaller than before. In a bathroom that is the difference between steam that lingers and steam that leaves.

A hallway between two rooms can be the darkest spot indoors, with roof space overhead and no outer wall. A sun tunnel sends daylight down a tube beneath a small roof dome, and a dome that size sheds a shower quickly.

Once the fixed written quote is agreed and the work is finished, our 10-year workmanship guarantee goes to you in writing. To begin with a free survey, ring 01792 929062 or use the online form.