Rooflight and skylight installation in Berechurch

Modern estate housing

The newest properties here are the easiest to work on and the most constrained in one specific way.

Trussed rafter roofs throughout, shallow pitches, and profiled concrete or clay tiles. A rooflight narrow enough to sit between trusses at 600mm centres goes in with no structural work. Anything wider needs a designed trimmer, which is routine but which is where the price changes.

The shallow pitch has two effects worth knowing. Less water sheds naturally, so the flashing detail is doing more of the work and the correct deep profile kit matters more than it would on a steep slate roof. And a shallow pitch gives less headroom gain and a longer reveal, so splaying the reveal rather than boxing it square makes a real difference to how much light actually reaches the room.

The constraint people do not expect is the deeds. Modern estates frequently carry covenants from the original developer restricting alterations to elevations facing the street. They are a private matter rather than a planning one, they are enforceable, and they are simple to check before rather than after.

New build warranties

Where a property is still within its structural warranty period, cutting a new opening in the roof can affect cover. It is not a reason not to do the work, and it is a reason to check the terms and to keep the paperwork showing the installation was carried out properly.

We provide a written specification naming the unit, the flashing kit and the detailing, and a ten year guarantee on the workmanship, which is what a warranty provider will ask for if the question ever arises.

Post war and garrison housing

Solidly built, concrete interlocking tiles, pitches around 30 to 35 degrees, and generally traditional cut roofs on the earlier blocks. Straightforward to work on and they take a roof window well.

These are the properties where replacement work is most common now, because a lot of skylights went into them in the 1990s and the sealed units are reaching the end of their life. Photograph the data plate before anything else and we can usually tell you what it is, whether the size is still made and what it costs, without a visit.

Extensions and the kerb

Whatever the age of the house, the rear extension is where most of the daylight work happens, and the detail that decides whether it lasts is the kerb.

At least 150mm of upstand, the deck falling away from it so water cannot pond against the seal, and rigid insulation on the outer face of the kerb itself. That last one appears on almost no quotation and matters more than the glass specification does.

A 1200 by 1800 rooflight has six metres of perimeter. An uninsulated timber kerb punching through the roof insulation presents close to a square metre of poorly performing envelope at a U-value several times worse than the glass sitting on top of it. Insulating it is a sheet of board and an hour, and it disappears under the covering, which is precisely why it gets skipped.

When comparing quotations, ask directly whether the kerb is insulated. It is the fastest way to tell who is detailing the job and who is fitting a unit.

Access

Generally good across Berechurch. Off street parking on most properties, wide estate roads on the modern development, and space to stand a tower at the rear. Single storey work rarely needs scaffold, which keeps the cost down noticeably compared with the terraced parts of Colchester.

Permissions

No conservation area covers the main residential estates, so permitted development normally applies to houses: no more than 150mm projection beyond the roof plane, and not above the highest part of the roof. Flats and maisonettes have no permitted development rights at all and always need an application. Where any older property is listed, listed building consent is required regardless of which slope the unit goes in.

Specify by orientation, not by habit

Quotations frequently arrive with identical glass on every unit regardless of which way each faces. That wastes money in both directions at once.

South. Most sun, through the middle of the day when it is strongest. Solar control is not optional. On a large area, consider external shading as well, because internal blinds stop heat after it has already entered the room.

West. Often worse in practice than south, because late afternoon sun is low and arrives when the building has been warming all day. Low angle sun is also where internal blinds struggle most.

East. Morning gain, shorter and cooler. Fine over a kitchen. Difficult over a bedroom, where the issue is light rather than heat and blackout provision is the answer.

North. No direct sun at all. Even, cool, glare free light all day and the best light in the building for a work surface. Specify for thermal performance alone and spend the saving elsewhere. Solar control on a north facing rooflight makes a good room slightly darker and delivers nothing.

Ventilation is the other half

Glass specification reduces how much heat arrives. It does nothing about the heat already in the room, and that is what an opening at high level is for.

Warm air rises. An opening at the highest point lets it leave and draws cooler air in through anything open lower down. The useful version is night purge: open it late, let the accumulated heat out of the building overnight, close it in the morning before the outside air warms. On a motorised unit with a rain sensor that happens without anyone thinking about it, which is the real argument for a motor over a pole.

Building Regulations Part F sets purge ventilation requirements for habitable rooms, and an opening rooflight contributes to that provision. Worth confirming the free area figure for the specific model at design stage, because a top hung unit and a centre pivot of the same size do not offer the same open area.

Part L and Part O on an extension

An extension is notifiable building work whatever else applies.

Under Part L the rooflights form part of the thermal calculation for the whole extension, so a poor unit forces better performance somewhere else in the build. There is also a limit on total glazed area as a proportion of floor area, which means a heavily glazed extension needs a calculation rather than an assumption.

Part O, the overheating standard introduced in June 2022, applies to new dwellings rather than to extensions of existing houses, so it usually does not bite on this work. Where a property is a new build within its warranty period, it will have been designed against it, and adding a large unglazed area of glass afterwards is worth checking against the original assessment.

The physics is the same either way. A south facing glazed extension will overheat whether or not anybody is required to calculate it.

What we guarantee

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

Most rooflight problems are installation problems, 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 that claim rather than leaving you to argue with a manufacturer about a product we chose and fitted.