Skylight costs in Swindon: where the money goes
A rooflight price is a bundle of separate costs. The unit itself is often the smaller part. Labour, access, the opening in the roof, the flashing or kerb, the internal lining and the Building Control fee make up the rest, and each of those changes from house to house.
That is why two quotes for what sounds like the same job can look very different. One may include scaffold, plastering and the Building Control fee; another may leave them out or price them later. When you compare rooflight prices, check that each quote names the same unit, the same size and the same list of work.
Our quotes list every part of the job separately, and the written job plan that comes with them shows what each part is for. Nothing is added on the day.
The unit type
The product is the first choice and the biggest single swing. A sun tunnel is a small, simple kit. A manual roof window for a pitched roof is a factory-made unit with a matched flashing kit. A frameless flat rooflight, an electric opening rooflight, a roof lantern and a walk-on unit each step up in glass area, frame engineering and weight.
Conservation rooflights cost more than a standard roof window of the same size, because the frame is slimmer, often steel or aluminium with a glazing bar, and set lower into the roof. Electric units add a motor, a control and usually a rain sensor, plus the wiring to reach them.
Size
Bigger glass costs more, but not in a straight line. Within a range of standard sizes, the step from one size code to the next is modest. Once a unit moves outside the stock range and becomes made to measure, the price and the lead time both rise.
Size also decides whether the roof structure needs changing. A roof window that fits between rafters at 600mm centres needs no structural work. A wider unit means cutting a rafter and adding trimmers, which brings in timber, labour and, on a larger opening, a calculation.
The roof covering
The roof the unit goes into shapes the labour. Concrete interlocking tiles are quick to strip and relay around a flashing kit. Natural slate takes longer and needs care to avoid breakages. Plain clay tiles, stone slates and older handmade tiles take longest of all, and reclaimed matches may be needed.
On flat roofs, the covering decides how the kerb or upstand is tied in. EPDM rubber, single-ply membranes, GRP fibreglass and felt each have their own detail, and an old felt roof near the end of its life may need a wider section renewed around the new opening.
Structural work
Cutting a new opening is building work. On a pitched roof that can mean trimming rafters and doubling the timbers either side. On a flat roof it can mean new joists or a timber kerb built to the manufacturer's size. A large roof lantern may need a steel or engineered timber support, and that needs a structural engineer's calculation for Building Control.
Replacing a unit in an existing opening of the same size usually avoids structural work altogether, which is why like-for-like replacement sits at the lower end of most ranges. Our answer on adding a skylight to an existing roof covers what a new opening involves.
Access and scaffold
Safe access is part of every job and it is priced in, not hidden. A single-storey extension may only need a tower or ladder access with edge protection. A roof window on the second storey of a terrace usually needs scaffold, and a terrace with no rear access means carrying everything through the house or arranging scaffold from the front.
Scaffold hire depends on height, the length of run and how long it stays up. If the pavement or road is used, a council licence may be needed, which adds a fee and some notice.
Glazing specification
Standard double glazing meets the Part L limits for most units. Triple glazing, solar control coatings, self-cleaning outer panes, laminated inner panes and acoustic glass each add to the price. Walk-on units always use thick laminated glass, which is heavier and costs more to make and lift into place.
Our energy efficient rooflights page explains when a better glass specification earns its cost and when standard glass does the job.
Finishing inside
Once the unit is in, the opening inside needs lining. That might be a manufacturer's lining kit for a roof window, plasterboard and skim, or a timber-lined light well through a loft space. Decoration, blinds and electrics for motorised units are further choices.
A light well through a deep loft or a sun tunnel run through a cold roof space adds materials and time. Your quote will say exactly which finishing work is included.
Building Control fees
Cutting a new rooflight or roof window into an existing roof counts as building work. Swapping a complete unit, frame and glass together, is a controlled fitting and must be notified. Either the local authority or a registered building control approver can act, and each charges a fee. Swindon Borough Council and the neighbouring councils publish their charges, and private approvers quote per job.
When the job is notifiable, we make the notification ourselves and the fee is a separate line on the quote. Replacing only the sealed glass unit in a sound frame is not notifiable, so that fee does not apply. Our guide to rooflight Building Regulations sets out the rules.
Typical UK market figures
The table below gives broad ranges seen across the UK market for supply and fitting by product type. They are a starting point for budgeting only. They are not our prices, they vary with every factor above, and they exclude VAT unless your installer says otherwise. Your written quote follows the survey.
Each product has its own answer page with more detail on what sits at the low and high end of the range.
| Product | Typical UK market range | More detail |
|---|---|---|
| Sun tunnel | £500 to £1,200 | Sun tunnel cost |
| Roof window, pitched roof | £700 to £1,800 | Roof window cost |
| VELUX window, like-for-like | £600 to £1,500 | VELUX window cost |
| Flat rooflight, fixed | £1,000 to £2,800 | Flat rooflight cost |
| Conservation rooflight | £1,000 to £2,800 | Conservation rooflight cost |
| Electric opening rooflight | £2,000 to £4,500 | Electric rooflight cost |
| Roof lantern | £2,500 to £7,000 | Roof lantern cost |
| Walk-on rooflight | £2,500 to £7,000 | Walk-on rooflight cost |
| Replacement glass unit only | £300 to £900 | Glass unit cost |
How rooflight prices move within a range
The same product can sit at either end of its range. These are the factors that most often push a job up or down.
What moves a job within its range
| Replacement in the same opening | Usually lower: no structural work, often no plastering |
|---|---|
| New opening with trimmed rafters | Higher: timber, labour and Building Control |
| Slate, clay or stone roof | Higher: slower stripping and relaying |
| Scaffold on a two-storey house | Adds hire and erection to the total |
| Made-to-measure size | Higher unit cost and a longer lead time |
| Upgraded glass or motor | Adds to the unit price |
Cost factors only. Figures for your house come in the written quote after the survey.
Getting good value from the budget
A few choices make a real difference to the final figure without cutting corners on the fitting.
Matching the opening helps most. If an old roof window is being swapped, a new unit in the same size code goes into the existing opening with the existing trimmers, so no structural work and little plastering are needed. Choosing a stock size over a made-to-measure one keeps both the price and the wait down.
Grouping work helps too. Two roof windows on the same slope share one scaffold and one Building Control notification. A rooflight planned while an extension roof is being built costs less than cutting one into a finished roof later, because the kerb, joists and covering are formed once.
Finally, spend where it shows. A motor is worth paying for on a unit you cannot reach; on a window at head height in a loft bedroom, a manual handle does the same job. Upgraded glass earns its cost on a large south-facing lantern more than on a small rooflight over a landing. The quote sets out these options so you can choose line by line.
From survey to written quote
A price given over the phone is a guess. We would rather see the roof. At the survey visit we measure the opening or the space between rafters, look at the roof covering and the structure, note the access and check the planning position for the house.
The written quote then lists the unit by name and size code, the structural work, access, glazing, finishing and the Building Control fee as separate lines. The job plan attached to it shows the lead time and the fitting day. You pay nothing for either, and you are free to say no.
To book a survey, use our free quote form. If you are still choosing a product, our service pages explain each one.