Rooflights and skylights in Caterham

Caterham sits in the North Downs around a dry valley, with ground running from 110 m to 236 m. That range is the first thing a roof in this town has to live with.

A dry valley is a chalk valley with no stream in it. The town grew in the bowl and up its sides, so two neighbours can be a full storey apart in height without being a street apart. For a rooflight, that matters in a plain way. A loft room on the upper slope receives the sky differently from a room down on the valley floor, where the hillside takes some of the horizon. The glass is sized and placed for the light that particular room gets, not for a standard drawing. Our guide to where to position a skylight in a room sets out the reasoning, and the guide to sizing a rooflight for the room covers the arithmetic.

Height also means exposure. A roof near the top of the hill takes rain and wind without much shelter, and rain arriving hard on flat glass is the sound people notice first. We come back to that below.

Caterham Barracks is the town's conservation area, designated in 1996, and Tandridge lists no other conservation area in Caterham. It is a short list with a distinctive entry on it.

The site was a Guards depot from 1877 until the 1990s. The 11-hectare ground was redeveloped with 361 homes, keeping the listed chapel and 18 other buildings. So the area mixes old military buildings with new build laid out around them, and the roofs within it were not all made in the same century.

What does that mean for a rooflight? It means the position of the address matters more than the style of the house. Inside a conservation area, the aim is to keep the character of what can be seen from the street, and the council looks at front slopes and at materials. Rear slopes and flat roofs out of public view can be a simpler conversation, although the answer depends on the building and on the local authority, which here is Tandridge District Council. The details of the rules are in our guide to planning permission for rooflights and skylights.

Every quote begins with a survey of the roof and a listen in the room. The survey is what turns the general description above into a specification for one address.

On the roof, we read the covering, the rafters or trusses, the pitch and the state of the felt beneath the tiles. Older houses in the valley and on the hill can have timber at odd spacings, and a newer conversion may carry a steel or a trimmed opening already. The opening we cut has to work with what is there, and we say what we find before we say what we propose.

In the room, we listen. We note whether the sound is a train, the road, rain on whatever is above, or simply a thin roof in a quiet street. We note where the sun will fall, where the room is cold, and where the furniture goes. The answer becomes the written quiet spec: the glazing build we propose, the seals, and how the upstand is finished. It is written so you can see the reasoning and ask about any line.

A rooflight is there for light. In a town built on a hill, with tight plots and terraced rows, a roof opening can bring more light into a room than a new wall window could.

Light from above is brighter than light from the side, and it reaches further into a room. A narrow Victorian or Edwardian terrace in the valley, deep and dark in the middle, changes character with a roof window over the stairs or a lantern over a rear extension. A top-floor flat with small windows gets a kitchen that feels twice the size. The quiet we specify is a second gain that comes with the glass, and it should never cost you any of the light. The two fit together because the same laminated pane that damps sound also keeps its clarity.

We use the word rooflight and the word skylight without fuss. The two name the same thing on a roof, and this short explainer says where the different habits come from. A rooflight or skylight installation in Caterham is, in the end, the same careful job whichever word you use for it.