Rooflight and skylight installation in West Bergholt

The older cottages

Steep pitches, small plan depths, irregular timber, and coverings of clay plain tile or slate depending on the age and whether the roof has been stripped since.

Plain clay tiles are the most demanding covering we work with. Small, laid in double lap, and brittle when old. Lifting them to form an opening is careful slow work and a proportion will break whatever is done. Matching weathered clay is difficult, and the usual answer is to take sound tiles from a rear or hidden slope and put the replacements there so the visible elevation stays consistent.

Underlay is the other unknown. A roof that has never been stripped may have none at all, just tiles on battens with the rafters visible from inside. Modern weathering detail assumes a membrane to lap into, and where there is none the detail is built around the opening. That is normal on a building of this age, it takes longer, and it belongs in the quotation rather than in a conversation on the day.

Rafters in these roofs are frequently smaller in section than modern ones, irregularly spaced, and not always straight. Where a wider skylight is wanted, trimming is likely, and on a small cottage roof that is a genuine structural consideration rather than a formality.

Conservation and listing

Part of the village is covered by a conservation area and there are listed properties within and around it. The two are separate regimes and they are commonly confused.

A conservation area does not by itself remove permitted development for rooflights on a house. What removes it is an Article 4 direction, which may or may not apply to your address, and which the council will confirm. Where permitted development survives, a rooflight is permitted provided it projects no more than 150mm beyond the plane of the roof and does not sit above the highest part of it.

A listing is absolute. Listed building consent is required for a rooflight regardless of which slope it goes in or whether anyone can see it, because the listing covers the whole building. There is no rear elevation exception.

Where consent is needed, a conservation rooflight is the design that gets through: low profile so it sits close to the plane of the tiles, upright rather than wide in proportion, with a central glazing bar, in matt black. On a rear slope screened from every public view, a case can sometimes be made for a standard unit, and it is worth asking rather than assuming the more expensive product is compulsory.

The twentieth century housing

Concrete interlocking tiles, pitches around 30 to 35 degrees, and a mixture of traditional cut roofs on the earlier properties and trussed rafters on the later ones.

You can check which you have yourself with a torch. Rafters running eaves to ridge with a purlin partway up and clear space between them is a cut roof, and a wide opening is ordinary carpentry. A repeating pattern of triangular frames with diagonal webs crossing the space, joined by flat steel plates, is trussed, and opening width is limited to the truss spacing unless a designed trimmer is installed.

That single distinction decides more about the price than the choice of window does, and a photograph looking up in the loft answers it without a visit.

Profiled tiles need a deep flashing kit rather than the flat kit used on slate. A flat kit on a profiled tile leaves voids under the tile profile that water finds within a season, and it is the most common installation fault we find on other people’s work.

Sun tunnels

Worth mentioning because the older cottages here often have internal bathrooms or hallways with no external wall and no available roof slope for a full skylight.

A rigid mirrored tube brings genuine daylight down from the roof into a room that has never had any, for a fraction of the cost of anything else. The roof component is small and low enough that on a rear slope it is effectively invisible from the road, which matters in a conservation area. It still needs listed building consent on a listed property, because it is not exempt for being small.

Specify rigid rather than flexible: a flexible foil tube scatters light at every fold and delivers roughly a third of what a rigid one of the same diameter gives. Size by diameter rather than by hope, because output goes with area, so 350mm passes about twice the light of 250mm. And insulate the tube where it crosses the cold loft, or condensation will form inside it and arrive at the diffuser looking like a leak.

Access and parking

Better than the tighter villages, though variable. The estate roads have off street parking and space to stand a tower. The older lanes near the centre are narrower, with limited parking and in some cases no side access to the rear, which means scaffold and materials need planning rather than improvising.

Where scaffold has to stand on the highway a licence is required from the county council, and it takes time to arrange. We deal with that where it applies and it appears as a named line on the quotation rather than as a surprise.

Getting a price

Send a photograph of the roof, one looking up in the loft, and the address. We will check the conservation and listing position ourselves. If you are replacing an existing unit, photograph the data plate on the sash rather than transcribing it, because the characters are small and a mistyped code buys the wrong window.

The reveal, which is half the light

A rooflight in a thick roof sits at the end of a tunnel, and how that tunnel is shaped decides how much of the collected light actually reaches the room.

A square boxed reveal throws a narrow beam straight down. A splayed reveal, cut back at an angle at the head and the sill rather than square, opens the beam out and can make a modest window feel considerably larger. It costs a little more in plastering and it is the best value upgrade available on any installation.

In a period room it also reads correctly where a square box does not, which matters on the older cottages here.

Timescales

A like for like replacement into a sound opening is a day. A new opening in a tiled roof with making good is three to four days depending on the plastering.

What lengthens a programme in a village like this is never the fitting. It is the lead time on a conservation unit or a made to measure size, which runs to several weeks, and the wait for consent where it is needed, which is measured in months. Start the permission first, order the unit second, and book the fitting to the delivery date rather than hoping.

Guarantee

Ten years on our workmanship: the flashing, the underlay collar, the frame fixing, the insulation collar and the making good. That sits alongside the manufacturer’s warranty on the product, which is separate cover from a separate party.

Most rooflight problems are installation problems rather than product failures, which is why the first one matters more. Where a unit does fail under a manufacturer’s warranty on a job we did, we handle the claim ourselves.