What a rooflight costs in Gloucester

Why an address moves the figure more than the unit does

The glass and the frame are catalogue items. A manufactured roof window in a given size code costs what it costs whether it is going to Longlevens or to Northleach. The labour, the access, the covering work, the consents and the material sourcing are all local, and together they are usually the larger part of the total.

Gloucestershire has a wider spread on that larger part than almost anywhere in England, because the county contains six or seven genuinely different building traditions within thirty miles of the city. Cotswold stone slate, Regency Welsh slate mansards, Severn Vale clay tile, Forest of Dean sandstone terraces, interwar concrete tile hips and modern trussed estates all sit inside the same working radius. Each one changes the day differently. That is why a figure quoted before anybody knows the postcode is a guess dressed up as a price.

Cotswold stone slate, and the courses that come back up the slope

This is the single biggest local difference and it is worth understanding properly, because it changes the shape of the job rather than adding a percentage to it.

Cotswold stone slate is laid in diminishing courses. The largest and thickest slates sit at the eaves and the sizes reduce steadily up the slope to the ridge, so no two courses share a gauge and the batten spacing changes continuously. Underneath, the slates are hung on riven battens and the joints are frequently sealed from below with a lime mortar torching, often with no underlay at all. An opening therefore cannot be cut through and closed around a frame. The courses above the position are stripped back up the slope, the frame is set, and the courses are re-laid downwards while the diminishing gauge is re-established so the finished roof still reads correctly from the garden.

That is skilled roofing time measured in days rather than hours, and it applies across Painswick, Bibury, Chipping Campden, Northleach, Bisley, Sheepscombe and the wolds villages between them. The slates are also 20 to 30mm thick and the roof loading runs well over 100 kilograms per square metre, so handling is slower and breakages are a certainty rather than a risk.

Sourcing reclaimed stone, and the wait that comes with it

Stone slates break when they come off. Some are already delaminating, some split at the peg hole, and a proportion of any strip is unusable when it goes back. New quarried stone is available but it reads as new against a two-hundred-year-old roof for a decade or more, which is exactly what a conservation officer is trying to prevent.

So reclaimed slate is sourced to match thickness, size and weathering colour, and reclaimed stone is a market with its own prices and its own lead times. A batch in the right size band may be a fortnight away or it may be two months away. That waiting time is a programme cost as much as a material cost, because it decides when the scaffold goes up. On a stone roof the honest sequence is to identify the material before a date is agreed, not afterwards.

Conservation rooflights, and the product the county forces

A standard roof window frame and its flashing kit are made for a covering a fraction of the thickness of stone slate. Fitted into one, the unit sits proud and reads as a modern object bolted onto an old roof. A conservation rooflight has a slim cast or pressed steel frame, one central glazing bar and a low profile designed to sit almost flush in a thick slate, and it is dearer than a mass-produced roof window of the same aperture.

That is not an upgrade in the ordinary sense. On a stone roof in a Cotswold conservation area it is frequently the only unit that will be accepted, so it belongs in the figure from the start rather than appearing as a variation later. Sizes, finishes and glazing options are on conservation rooflight installation.

Consent time in Cheltenham, and the work that happens before the scaffold

Central Cheltenham is Regency stucco, Welsh slate and mansards, and a great deal of Lansdown, Montpellier, Pittville and the Bath Road terraces is listed. Listed building consent is required for an alteration whether or not anyone can see it, and on a listed building the internal reveal counts as much as the external face.

What that adds is professional time before any physical work starts: photographs of the roof, a description of exactly what is proposed, pre-application advice from the conservation officer, and often a drawing. It is time well spent, because officers in this county have seen a great many rooflight proposals and will usually indicate early what would be acceptable. It is far cheaper than a refusal with the scaffold already up. The consent position itself is set out on conservation areas and listed buildings in Gloucestershire, and the permitted development limits on permitted development limits for rooflights.

There is a technical consequence too. The shallow upper slope of a mansard, hidden behind a parapet, is often below the pitch a manufactured roof window is rated for, so the unit becomes a kerb-mounted one on a small upstand. That is a different product at a different price from the in-plane window the customer had in mind.

Scaffold in the Stroud valleys, and material carried by hand

Stroud, Chalford, Rodborough, Brimscombe and Nailsworth are built into steep sides. Terraces step up the hill so a cottage is one storey at the front and three at the back, access is by shared lane, footpath or a flight of steps, retaining walls sit hard against the elevation, and there is often nowhere flat to stand a tower.

The practical effect is that scaffold tube and boards are hand-carried in, sometimes fifty or a hundred metres and sometimes up steps, and a large made-to-size unit may need extra hands or a mechanical lift where a lorry cannot get close. Scaffold on a valley site can take most of a day where the same scaffold on a Hucclecote driveway takes two hours. This is priced from a proper look at the access rather than assumed, which is the whole reason the fixed price waits for a visit. Access in general is covered on do you need scaffolding to fit a rooflight.

Gloucester terraces, party walls and the two month notice

Gloucester’s Victorian and Edwardian terraces around Barton, Tredworth, Kingsholm and Linden share a shape: red brick, clay tile or slate, a two-storey rear addition one room wide, and neighbours on both sides within a few metres.

A rooflight in the middle of a slope rarely engages the Party Wall etc. Act 1996 on its own. What engages it is the structure a larger opening sometimes needs: a beam bearing into the party wall, or a strengthened purlin picking up on it. Notice periods for party structure works run to two months, and that is calendar time somebody has to plan around even where the neighbour agrees immediately. On a terrace it is worth checking the structural strategy against the party wall early, because a position 600mm along the slope can sometimes avoid the whole question.

Scaffold on a terrace has its own local cost. There is often no side access, so material goes through the house or over the rear boundary, and where the pavement is narrow the scaffold may need a licence from the highway authority.

Severn Vale rear additions, and the run of slope that dictates the unit

The rear addition roof on a vale terrace typically gives 1.8 to 2.4 metres from gutter to abutment at 22 to 30 degrees. A standard roof window plus the flashing lap it needs above and below consumes most of that. The result is that the unit which fits is often smaller than the unit the room wants, and the alternatives are two small units or a made-to-size rooflight on the flat area where the addition meets the back of the house.

That matters to the figure because two openings cost more than one, and because a made-to-size flat roof unit is a different product line with a different price basis from a catalogue roof window. Sizes are on flat rooflight standard sizes and made to measure.

Flood history is the other vale factor. Homeowners along the Severn and the Avon through Tewkesbury, Longford, Sandhurst and Maisemore have watched water come into their houses and are reasonably sceptical about anything involving a hole in a roof. The answer is time spent on the perimeter detailing and a sequence in which nothing is left open, both of which are in the price rather than added to it.

Interwar hips at Longlevens and Hucclecote, where two units beat one

The interwar and post-war semis across Longlevens, Hucclecote, Tuffley, Coney Hill, Warden Hill and Charlton Kings are cut roofs at 30 to 35 degrees with concrete interlocking tiles, purlins across the middle and hips at the corners. Structurally they are the easiest roofs in the county to work on and the tile is the most straightforward covering to lift and re-lay.

The constraint is geometry. A hip narrows the slope towards the corner and a purlin cuts the usable run in half, so the clear zone on a typical rear hip is often around 1.2 metres of vertical run across two rafter bays. People arrive wanting one large window and the roof will take a shorter one. Two units in adjacent bays generally give more glass in total, light the room more evenly, and need no structural design at all, which makes them cheaper than the single wide unit that would have required a trimmer. That comparison is on two rooflights side by side on one slope.

Trussed estates, and the member that has to be designed

Quedgeley, Abbeydale, Brockworth, Bishops Cleeve, Ashchurch, Churchdown and Yate are largely trussed rafter construction at 600mm centres. Between two trusses there is around 550 to 570mm of clear width, and manufacturers make narrow units precisely for it. A unit in that band needs a head and cill trimmer between the trusses and nothing more, and it is one of the least expensive installations available anywhere in the county.

Go wider than the bay and the cost profile changes step by step rather than gradually. Part of a truss comes out, the load is carried on a beam spanning to the trusses either side, and that means a structural engineer’s calculation, a heavier member, and Building Control approval before the covering is touched. It is regularly the right thing to do for a loft room, and it is a different job with a different figure. The detail is on rooflights in a trussed roof and what cannot be cut.

Forest of Dean exposure, and the details built heavier

Coleford, Cinderford, Mitcheldean, Lydney and the villages between them are local sandstone with Welsh slate, often over sarking boards, at 40 to 45 degrees. The Forest is wetter and windier than the vale and driving rain arrives from the south west with force behind it.

Head laps get increased over the manufacturer’s minimum, side flashings are taken wider, and lead is specified a code heavier where it is exposed. Those are small material increases and a real increase in labour, and they are the correct response to the exposure rather than an optional extra. Steeper pitches also change the working method: more of the day is spent on a scaffold with edge protection and less of it standing on the slope, and reaching an opening handle from the floor stops being realistic, which often makes a rod-operated or electric unit the sensible specification rather than a luxury one.

Thirty miles by road, and what a lane does to a delivery

Severn works within thirty miles by road of Gloucester. That radius takes in the city and its suburbs, Cheltenham and the villages around it, Stroud and the valleys, Tewkesbury and the vale, the Cotswolds east to Cirencester and Northleach, the Forest of Dean, and south through Yate and Thornbury. Ledbury, the Malverns and Newent sit inside it to the north.

Thirty miles across the vale on the A38 and thirty miles up into the wolds on single track lanes are not the same thirty miles. Glass deliveries need a vehicle that can turn, unload and get away, and where it cannot reach the house the material transfers to a smaller vehicle or gets carried. Waste goes out the same way it came in. None of this is dramatic and all of it is time, so it is looked at during the survey and written into the fixed price rather than discovered on the morning. Coverage town by town is on the areas pages.

Building Control, and six authorities inside one radius

Forming a new opening is notifiable work and so is replacing a unit in most circumstances. Inside the working radius the application goes to Gloucester City, Cheltenham Borough, Tewkesbury Borough, Stroud District, Cotswold District, Forest of Dean District or across the boundary into South Gloucestershire, Herefordshire or Wiltshire, and the fee scales and inspection practices are not identical.

The notification is submitted and closed out as part of the job, the inspections are booked around the programme, and the completion certificate comes back in the homeowner’s name. Where a structural calculation is needed it goes in with the application, and that engineer’s fee is a real line rather than a rounding. The regulatory picture is set out on rooflight planning permission and building regulations.

What changes the figure that has nothing to do with the county

Local conditions sit on top of the ordinary variables, and it is worth naming them so the local part is kept in proportion. Unit size and how it opens. Whether the glass is double or triple, and whether it carries a solar control coating. Fixed, manual, rod-operated or electric. How many units go in under one scaffold. How far the internal finish is taken, from a bare opening to a plastered and decorated splayed reveal. Whether the room below is finished and furnished. Those are the same anywhere and they are covered properly on costs, with the anatomy of a written figure on reading a rooflight quotation properly.

The interaction is where Gloucestershire reasserts itself. An electric unit is worth more here than in a bungalow county, because a great many of these houses put the glass out of arm’s reach: valley cottages with three storeys at the back, Forest terraces at 45 degrees, Cheltenham stairwells. Solar control glass earns its place on any west-facing rear slope in the vale. The specification that suits the county is not always the cheapest one on the sheet.

A range by email first, then a fixed price once the roof has been seen

There are no figures published on this site and the pages above explain why: a published number would be wrong for a Painswick cottage and wrong for a Quedgeley semi, in opposite directions. What happens instead is two figures, in this order.

First an indicative range by email. It is based on photographs of the roof from outside and the room from inside, the covering if you know it, a rough size, and the address. It is free, it takes a day or two, and it exists so nobody spends an afternoon on a survey for a project that was never going to work financially. Second, after a survey, a fixed price, itemised so it is clear what is unit, what is labour, what is scaffold, what is covering work and what is Building Control. That figure holds unless the scope changes at your request, or unless something structural is uncovered that was written down as a risk in the survey notes beforehand. What the survey looks at is on how a rooflight survey works.

To start, email info@severnskylightsgloucester.co.uk with those photographs and the address. The address does a surprising amount of work here, because on a Gloucestershire roof the covering, the exposure and the conservation status are often obvious from the postcode before anybody looks at a picture. The full technical picture of what is being installed sits on the skylight and rooflight installation hub.