Skylight and rooflight fitting in Glanamman

Glanamman is a mining village in the valley of the River Amman in Carmarthenshire, and the Welsh spelling of the name is Glanaman. Before coal arrived, the place and its neighbour Garnant were known together as Cwmamman, the Amman valley. Until the 18th century it was remote wilderness: a few farms and rough mountain roads.

Mining appears to have started at Brynlloi in 1757, and small coal workings multiplied through the first half of the 19th century. A turnpike road along the valley, now the A474, was built in 1817. The railway followed in 1840, which meant coal could be shipped on an industrial scale through Llanelli docks. Two stations, one at Glanamman and one at Garnant, helped to set the two communities apart from each other.

The largest pit in the village was opened in 1891 by the Gelliceidrim Collieries Company, and it employed 632 men in 1932. The last big colliery closed in 1947, although coal has been taken out in fits and starts since.

The village is about 16 road miles north of Swansea, comfortably within our 30-mile radius, and our work takes in Garnant and Gwaun-Cae-Gurwen too.

Villages that grew in a coal boom were often built in terraces, and terraces of that kind usually have long, narrow back slopes. A single roof window can light a back bedroom or a bathroom without a dormer. Houses from later decades can have a wider slope, with room for two windows side by side. These are the general patterns for the house types. The house itself is what we look at when we visit.

Exposure is the other thing a survey records. A slope that faces the open valley meets driven rain differently from one sheltered by the house next door, and the position of the window on that slope affects how it is flashed and how easily you can reach it to clean.

A Glanamman address comes under Carmarthenshire County Council for planning. Glanamman sits beyond the reach of the Gower AONB designation, so that landscape rule is not part of the decision.

On a house, many rooflights need no planning application as long as they stay inside the limits explained in the skylight planning permission page for Wales. Flats and maisonettes sit outside those householder rights altogether. A council can withdraw the rights from a street through an Article 4 direction, and one house can lose them through a condition attached to its first planning permission. A listed house needs listed building consent, applied for through the council, where a rooflight would affect its character, under the Historic Environment (Wales) Act 2023.

If the limits look borderline for your house, put the question to the council. A Lawful Development Certificate from the planning team puts the answer on paper before work starts.

Building Regulations are the second gate and have their own approval. Cutting an opening for a new rooflight usually alters the roof structure, so approval is generally needed, and the new unit is checked for strength and energy efficiency. Notifiable jobs are ours to notify: we deal with local authority building control or a registered building control approver for you. Swapping one roof window for another of the same size is building work as well.

Listing is checked at Cadw, the Welsh Government's historic environment service, which publishes each listed building record in Cof Cymru. Work on a listed house carried out without consent can amount to a criminal offence, so check the address before a rooflight is priced.

Ask about the finish as well as the figure. Approved Document L (Wales) allows a new or replacement roof window to be rated by U-value, 1.4 W/m²K at most, or by Window Energy Rating Band B. A bigger window than the old one means the timbers around the opening need looking at, and that is survey work, done before any figure is fixed. Either way, the glass should be fitted well and be reasonably draught-proof, and the survey is where we check how the frame meets the roof.

Start with the landing. In a terraced house it can sit between two bedrooms with loft space overhead, which leaves no wall to hang a window in. A sun tunnel reaches it from the roof: a dome outside, a reflective tube, a diffuser in the ceiling. Rain meets only the dome, and runs off it.

A loft bedroom has the opposite problem, which is air. A roof window that opens lets stale air out, and a centre-pivot sash turns so the outer pane can be wiped from inside. Where the glass sits too high to reach, a motor and a rain sensor handle the opening and closing, and the electric opening rooflights page shows how they behave. A bedroom up there also has a fire-escape rule to meet, and our roof window Building Regulations guide goes through the Welsh guidance.

If yours is an older VELUX, VELUX stamps the size code on a plate along the top edge of the sash, and the VELUX windows page explains a like-for-like swap.

Between a sun tunnel and a roof window the trade-off is simple. The tunnel brings light and nothing else, through a small hole in the roof. The window brings light, air and a view of the sky, through a larger opening. The room and the roof decide which one fits, and the survey weighs them up.

Behind the kitchen, a flat roof wants different glass. Glass for that roof is a flat roof rooflight raised on a kerb, laid with a fall so the water can leave. A roof lantern sheds rain down its pitched panes. Under Approved Document L (Wales), a new or replacement rooflight in an existing home should reach 2.2 W/m²K. A lantern planned into a new extension is one we check with the council first.

Reach decides upkeep. Glass within arm's length gets a cloth. Glass above a stairwell does not, and that is the place to ask about Pilkington Activ, a self-cleaning coating whose maker lists roof glazing among its applications.

Cloudy glass with moisture trapped between the panes points to a failed seal. Our misted rooflights page covers swapping the unit.

To start, ring 01792 929062 or book your survey online. The survey is free, the quote is fixed and written, and the guarantee on our workmanship runs ten years in writing.