Skylight and rooflight fitting in Colwinston

Colwinston, Tregolwyn in Welsh, lies within half a mile of the A48 in the Vale of Glamorgan. The older village houses stand on higher ground overlooking meadows, possibly on the sites of older simple dwellings. Some of the original houses fell into disrepair as people moved away, and some of the area around Garden Cottage, Penlan Cottages and Church Cottage is thought to have given livestock shelter and water.

Farming shaped the village. A parish record counts fourteen to fifteen hundred acres of enclosed land, with 60 acres of common pasture called the Golden Mile. That common, about 70 acres alongside the A48, was enclosed by an Act of Parliament, the Golden Mile Award, in 1871. As machinery reduced the need for farm labour, some people left for the South Wales coalfields and the village shrank.

It has grown again. About 400 people lived here in 2005, and with recent building the estimate now stands above 600. A rising number of roofs means a village whose houses were built at different times, which is another reason we describe jobs by roof shape and never by a street's reputation.

For anyone thinking about a loft room, a rear extension or a replacement, that history has a use. A house that has stood on higher ground for generations has met a great deal of weather, and a roof that has done so is worth looking at closely before glass is added to it: the covering, the rafters and the flashing details all matter to how a new window will sit.

The village is older still. William de Londres was granted the lordship of Ogmore, which took in Colwinston, by Fitzhamon, and he founded Ewenny Priory in 1141. The area had been ruled earlier by the medieval princes of Morgannwg, and Roman activity left its mark across the Vale along the line the A48 later followed.

Reaching Colwinston from Swansea means 25.76 road miles heading south-east, comfortably inside our 30-mile area. We also fit rooflights in nearby Corntown and Wick as well, and in St Brides Major and Bridgend.

The Welsh Government's map of conservation-area boundaries includes one named Colwinston. Its edge lies about 96 m from the reference point we use for the village, which makes this the first thing to settle for any house here.

The rule in Wales is stricter than the one many people expect from English guidance. A new rooflight in the roof slope of a house inside a conservation area needs a planning application, and permitted development does not cover it. Before you plan anything, find out whether your address is inside the boundary. The map is not drawn property by property, so the council has the final say, and Vale of Glamorgan Council is the place to ask.

A house outside the line stands differently. It may qualify for permitted development, and the conditions are in our guide to rooflights and planning in Wales.

Whatever your location, three other starting points are worth knowing. Flats and maisonettes do not have these rights. A council can remove them from houses by serving an Article 4 direction, while a condition attached to the house's first permission can take them away as well. And on a listed house, an alteration that affects its special interest needs listed building consent, applied for through the council with Cadw consulted.

Older roofs have a product of their own in the conservation rooflight, which is made to suit them and merits a conversation for any period house in the area. We fit them, and the conservation rooflights page describes the range.

Building Regulations are the other track. Opening a new hole in a roof generally needs approval, in part because the structure has to carry the glass. A like-for-like replacement is building work as well; repair on its own is not. Where it is notifiable, we handle the notification, going to local authority building control or a registered building control approver as you prefer.

An older village roof usually raises a question of looks before it raises a question of performance. Inside a conservation area, the glass has to suit the roof and satisfy the council, which is the reason conservation rooflights exist. They are built to sit low in the slope of an older covering.

The replacement of an existing roof window has its own rules. In Wales, a new or replacement roof window should reach 1.4 W/m²K or Window Energy Rating Band B. For a house of historic interest where that cannot be met, the fallback is 1.2 W/m²K at the centre of the pane, or low-e secondary glazing. Our pages on roof windows and energy-efficient rooflights deal with the choices.

Good glass costs thought at the start and little afterwards. Choosing a unit with a coating for dirt, a laminated inner pane, or glazing aimed at rain noise are all matters VELUX lists as options, depending on the window and its variant. We go through what applies to your roof when we have seen it.

Recent building in the village points to a different job. A newer house or an extension with a flat roof suits a flat roof rooflight with a proper fall, or a roof lantern standing on an upstand. Brett Martin's technical note sets a minimum height of 150 mm for the upstand under its lanterns, and the energy figure for a lantern is something we settle with you at survey. A rooflight proper should reach 2.2 W/m²K.

A windowless hall or landing can take a sun tunnel. It collects light at a small dome and delivers it through a tube.

The loft is the other place for glass. A roof window above a bed benefits from an opening that does not need a hand on the pole, and electric opening rooflights close on a rain sensor in VELUX's electric and solar models.

Units fitted years ago do eventually fail. Once a sealed unit has misted, misted rooflights can be replaced, with a VELUX matched from the code on its type sign. Starting is straightforward. The survey costs you nothing, the quote you receive is fixed and in writing, and our workmanship carries a guarantee of 10 years, also in writing. Ring 01792 929062 or complete the survey form.