Rooflight and skylight installation in Stanway

The modern estates

Trussed rafter roofs throughout, shallow pitches typically between 25 and 30 degrees, and profiled concrete or clay interlocking tiles.

Trussed rafters are engineered components in which the rafter, the ceiling tie and the internal webs act as one triangulated unit connected with pressed steel plates. Cut any member and the load it carried goes somewhere it was not designed to go. A unit narrow enough to sit between two trusses at 600mm centres goes in with no structural work at all, which is the quick and inexpensive job. Anything wider needs a structural trimmer designed by an engineer, and that is where the price step is.

It is also why loft conversions are uncommon on these estates despite the houses being a reasonable size. Converting a trussed loft means replacing the roof structure rather than clearing it out, which is a different order of project.

The shallow pitch has consequences that matter more than people expect. Water sheds more slowly, so the flashing kit is doing more of the weathering work and the correct deep profile kit for the tile becomes critical rather than merely preferable. Headroom gain from a roof window is smaller than on a steep roof, and the reveal is longer and shallower, which blocks a surprising amount of light. Splaying the reveal, cutting it back at an angle at the head and sill rather than boxing it square, is the best value upgrade available on a roof of this pitch.

Where the work actually is on the estates

Rear extensions, overwhelmingly. A great many Stanway houses have gained a kitchen or garden room across the back, and that flat or mono pitch roof is where the daylight goes in.

The first thing we look at is the kerb. A rooflight bedded straight onto a flat deck sits in whatever water the roof holds, and every flat roof holds some. What makes the difference between a twenty five year installation and a problem in three winters is an upstand of at least 150mm, the deck falling away from it, and rigid insulation on the outer face of the kerb itself.

That last item appears on almost no quotation and matters more than the glass does. A 1200 by 1800 rooflight has six metres of perimeter, and an uninsulated timber kerb punching straight through the roof insulation presents close to a square metre of poorly performing envelope. Insulating it costs a sheet of board and an hour, and it vanishes under the covering, which is exactly why it is the first thing dropped.

Overheating on the newer housing

Worth raising here specifically. Modern airtight, well insulated houses with large glazed extensions overheat readily, and a good number of Stanway rear elevations face south or west.

Solar control glass on those orientations is not an optional extra. It costs a modest premium at the point of order and a great deal to change afterwards, because the labour and the access are identical either way. On north facing slopes, specify nothing extra: there is no direct sun, the light is even and glare free all day, and solar control would only make a good room slightly darker.

The other half of the answer is an opening at high level so accumulated heat can leave. Warm air rises, and an opening at the top of the room draws cooler air in through anything open lower down. On a motorised unit with a rain sensor that happens overnight without anyone thinking about it, which is the practical argument for a motor over a pole.

The older village

A completely different proposition. Traditional cut roofs with rafters and purlins, steeper pitches, and coverings that include clay plain tile and slate as well as later concrete.

Cut roofs give real freedom. Forming or widening an opening is ordinary carpentry, wide rooflights are possible, and loft conversions work properly. The trade off is that the roofs are older, the timber is more variable, and what is found on strip out is less predictable. Any honest quotation on a property of this age names a contingency for decayed timber rather than pretending it cannot happen.

Some of the older properties around the church are listed and parts of the historic core carry conservation designation. A listing removes permitted development entirely and listed building consent is required for a rooflight on any slope regardless of visibility. In a conservation area, permitted development survives unless an Article 4 direction removes it, which is worth checking with the council rather than assuming either way.

Covenants on the new build

The constraint people do not expect. 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 in the deeds before rather than after.

Where a property is still within a structural warranty period, cutting a new opening can affect cover. That is not a reason to avoid the work; it is a reason to check the terms and keep the written specification and guarantee showing the installation was carried out properly.

Access

Among the easiest in the district on the modern estates: off street parking, wide roads, open frontages and space to stand a tower at the rear. Single storey extension work rarely needs scaffold at all, which keeps the cost noticeably below the terraced parts of Colchester.

The older lanes are tighter, with limited parking and narrower access, and two storey work there is more likely to need scaffold and more planning around where it stands.

What to send

A photograph of the roof from outside, one looking up inside the loft, and for an extension one showing how the flat roof meets the house. The loft photograph tells us cut or trussed, which is the question that decides the price, and the extension photograph shows us the kerb and the fall.

When the size is obsolete

Common on anything fitted before about 2000, and entirely solvable. Three routes, in order of preference.

Adapt the opening to the nearest current size. Current sizes are frequently within 40mm or 60mm of an old one, and adapting means packing out or trimming back then making good the reveal. It is invisible when finished and it leaves a standard size for the next thirty years.

Find another manufacturer at the old dimension. Worth it where the opening is genuinely awkward to alter, for instance tight against a truss or a party wall.

Reframe to a current size. More work now, and right where several windows are being standardised or the timber needs replacing anyway.

What nobody should do is force a unit into an opening it does not fit and pack the difference. It survives about a year before the packing settles, the frame goes out of square and the sash stops closing properly.

The free glass upgrade

A unit fitted twenty five years ago has no low emissivity coating, no argon, an aluminium spacer and no solar control. The replacement has all four as standard, so the room will be warmer in winter, cooler in summer and quieter in rain without paying extra for any of it.

Where the window faces south or west, the marginal cost of adding solar control glass at this point is small, because the labour and access are already being paid for. Coming back for the glass alone later costs nearly as much as the whole replacement.