Rooflights and skylights for Cuckfield, sandstone village to brick extension

Cuckfield's buildings are made of what the ground around it offered. That is the useful thing to know before anyone talks about glass, because the roof, the walls and the rules all follow from it.

The oldest layer is timber and stone. The council's 2006 appraisal says the church is built largely of local Cuckfield sandstone, and that buildings from before 1500 are timber framed on sandstone bases. The church dates from the 13th century and is Grade I listed. Ockenden Manor goes back to the late 16th century. A house with a frame of that age is the opposite of a modern truss roof. Its timbers were cut one at a time, for one building, and no two bays agree.

Then came brick. The appraisal describes near-complete dominance of local brick in the 18th century, dark red from the iron in Wealden clay, and brick stayed the main material afterwards. Walls of that colour, topped with clay tile, are the picture the village brings to mind.

Cuckfield has two conservation areas, and Mid Sussex District Council is the planning authority for both. Whether your house sits inside one is a fact checked for the address, never one assumed from the street name.

The Cuckfield Conservation Area covers South Street and High Street. It was designated in 1969 and extended in 1989 to reach Courtmead Road. The second, Whitemans Green, was designated in 1989. Each has its own appraisal, and the council publishes both. If your house is inside either boundary, the planning position is worth settling before the survey is booked.

On top of that, the council made an Article 4(2) Direction in 1995 covering part of the Cuckfield Conservation Area. An Article 4 direction removes some of the changes that would otherwise need no application, which can include alterations to a roof. Which properties it touches is a matter for the council's map, and the check is made against your address. Our guide to planning permission for rooflights and skylights explains the general rules, and Mid Sussex District Council is the place to look up an application.

For Cuckfield the noise we plan around is the one every roof has: rain. On a flat roof extension, a pane of glass is a drum. A heavy downpour hits the outer sheet hard, and a thin single layer, or a lantern with slim bars and a rigid frame, carries the sound straight into the room below.

A brick extension added to an older Cuckfield house is a natural place for a flat rooflight or a lantern. A kitchen at the back of an old house is also a room where people talk and cook while it rains, so the sound is heard at its worst moments. We choose the build to suit. A laminated acoustic inner pane, panes of unequal thickness, firm seals and a well-made upstand all reduce how much reaches the room. It needs the right specification, written down.

A roof window in a tiled slope behaves differently. Rain on a pitched pane runs off, and it is gentler than on a flat one. The noise there comes more from thin glass and tired seals, and from wind finding a gap in an old frame. Our guide to reducing rain noise under a flat rooflight goes further into the build-up, and acoustic laminated glass explained describes how the glass itself works.

A roof that has stood for centuries is not a flat plane, and a rooflight has to be fitted to what is actually there. That is the main difference between work in Cuckfield and work on a recent estate.

Older frames move. Rafters have settled, purlins sag a little and the tile courses follow them. Before an opening is marked out, we look from inside the loft at how the timbers run, and from outside at how the tile courses lie. The aim is to keep the rafters uncut wherever possible. Where one has to be trimmed, a new trimmer is fixed either side to carry the load, and the size of the timber is set by the span and the loading.

Building Regulations apply to the work. Part L covers the thermal performance of the new unit, Part K covers the safety of the structure and of glazing where it might be reached, Part B covers fire where a roof is close to a boundary, and Part F covers ventilation. We install to current Building Regulations and handle the Building Control notification where the work is notifiable. Our guide to Building Regulations for rooflights lays out the detail.

These are the questions a Cuckfield homeowner is likely to ask before booking a survey. Each answer comes from the facts of the village and the roof.