Rooflights and skylights in Bromley, stock brick and slate

Bromley is about 9.5 miles south-east of Charing Cross and is one of 13 metropolitan centres in the London Plan. That makes it a real town with its own streets, stations and history, not a dormitory corner of somewhere else.

The population was 97,540 at the 2021 census. Because Bromley is a London borough, there is no county council layer above it. The London Borough of Bromley is the local planning authority, so one body answers questions about a roof alteration, a listed building or a conservation area. For a householder that is a short chain: your address, the borough, and the rules it publishes.

We work from Crawley, and Bromley is 28.1 road miles away. That is inside our 30-mile reach, though only just, so a survey here is a planned visit and not a quick call in passing. We would look at the roof from outside, from inside the loft and from the room beneath, and we would write down what we find before anyone talks about a product. If you want to compare the neighbouring places, our pages for Biggin Hill and Croydon describe the setting on either side.

The Bromley Town Centre Conservation Area appraisal describes two-and-a-half storey London stock brick houses, with red brick front elevations, stone dressings and pitched slate roofs. The appraisal and management plan was reissued in June 2025, replacing the 2011 edition and reflecting a small extension designated in 2021.

A two-and-a-half storey house tells you something before you climb a ladder. The half storey is the roof space, and in a house of that type it is often the part with room to spare: a room in the roof, or a loft that could become one. Those are the rooms that depend most on roof glazing, because the only daylight they can have comes through the slope or a dormer.

Pitched slate is a good covering to work with and an unforgiving one to rush. Natural slate is brittle at the edges and it is laid in overlapping courses, so a roof window needs a flashing kit matched to the covering. The slates around the opening are lifted, the flashing is lapped under the course above and over the course below, and the slates are then relaid in the same pattern. A window that sits proud of the slope looks wrong on a street like this, which is why a low-profile unit that sits flush with the covering is the usual choice on a slate roof in a protected area. Our page on conservation rooflight installation explains that choice in full.

The borough has 47 conservation areas, and that number is the single most useful fact on this page for anyone who lives in a pre-war street. Whether your house is in one is a question about the address, not the town.

The town centre area is only one of them. Park Langley's first phase was designated a conservation area in 1989, and the borough's own conservation pages list the others. The status of any house is checked for the address, against the borough's published information, before a product is chosen.

A conservation area does not forbid a rooflight. It changes what is sensible and what needs permission, and the usual trigger is the slope that faces the street. Roofs at the back, out of public view, are treated differently from roofs at the front, and the rules about what can be done without a planning application differ again for a flat, a listed building or a house whose permitted development rights have been removed. All of that is knowable before work starts.

Noise from rain has nothing to do with location. Any flat or shallow roof with glass in it drums in a downpour, and a rear extension in Bromley behaves like one anywhere else in south-east England.

Rain is loud on glass because glass is stiff and thin, and a raindrop is a small hammer. A lantern over a kitchen has a large area of glazing above a room with hard surfaces below, which is the worst combination for sound. The fix is partly in the glass: a laminated inner pane damps the vibration of the outer one. It is partly in the frame: a stiff frame on a solid kerb rattles less than a light one on a thin upstand. And it is partly in the room: a lantern above an open-plan kitchen with a tiled floor and hard worktops will sound louder than the same lantern above a carpeted room.

A flat rooflight set in a flat roof needs a fall in the roof around it, written as a ratio such as 1:80, so that water runs off and does not stand on the glass. The upstand, which is the raised kerb the unit sits on, is built up to a proper height and finished in the roof membrane, and the flashing is lapped over it. Our pages on flat roof rooflight installation and roof lantern installation describe the build, and the guide to reducing rain noise under a flat rooflight explains the glass and seal choices that matter most.

Every quote from us comes with a one-page quiet spec. One could look like this for a room of the kind the conservation area appraisal describes.

The room is a loft bedroom in a late Victorian stock brick house with a pitched slate roof. We would stand in it and listen. If it sits near the railway, we would note the trains. If it faces a busy road or a rear garden, we would note that instead. We would look at the existing slope, the rafters and the lining, and we would check the conservation position for the address.

From that we would propose a flush roof window on the rear slope, fitted between existing rafters with a slate flashing kit. The glass would be a laminated acoustic pane on the room side, a thicker pane outside and a warm-edge spacer between them. The gaskets would be continuous, the flashing lapped to the slate and the lining insulated to meet the thermal requirement in Building Regulations Part L. Where the work is notifiable, we handle the Building Control notification.