How Much Does a Loft Conversion Rooflight Cost?
A loft conversion rooflight typically costs between £1,900 and £3,100 per unit supplied and fitted in the Ipswich, Suffolk and north Essex area, including the correct flashing kit, the underfelt and insulation collars, and trimming one rafter where needed. A common two-unit loft scheme runs around £3,400 to £4,700 in total, because the second unit shares the scaffold and set-up. An escape unit, needed where the room has no protected stairway, sits at the upper end. The figure moves with unit size, whether it is a top-hung or escape unit, the roof covering, and whether the room needs a Part B fire escape window.
This answer is loft-specific. The full cost breakdown across all pitched work is on pitched roof rooflight installation cost, and how many units your room needs is on how many rooflights a loft conversion needs.
Per-unit cost in a loft conversion
| Unit | Typical range |
|---|---|
| 780 x 1180mm centre pivot, one rafter trimmed | £1,900 to £2,650 |
| 780 x 1400mm top hung, one rafter trimmed | £2,250 to £3,100 |
| Part B escape unit, top hung, to required clear opening | £2,400 to £3,300 |
| 1140 x 1180mm, one or two rafters trimmed | £2,600 to £3,600 |
Per-unit figures for a standalone or first unit. Additional units on the same slope cost less each because they share access and set-up.
Multi-unit loft schemes
Most loft rooms above about 14m² take two units placed apart, because two light sources from different points beat one large opening and remove the single hard shadow. When you fit two, the second is cheaper than the first, because the scaffold, the set-up and the survey are shared. A typical two-unit scheme of 780 x 1180mm units runs around £3,400 to £4,700 in total, against roughly £3,800 to £5,300 if you bought them as two separate jobs with their own scaffolds. Three units on the same slope scale the same way. The daylight case for two over one is on loft rooflight daylight levels.
What moves the figure
- Escape requirement. If the loft room needs a Part B fire escape window, that dictates a top-hung escape unit of a minimum clear opening, which sits at the upper end of the range and rules out a cheaper centre pivot. This is a hard requirement, not an upgrade.
- Unit size and type. A top-hung unit costs 15 to 30 per cent more than a plain centre pivot, and a larger unit needs more rafters cut. The choice between them is on centre pivot or top hung.
- Roof covering. Deep clay pantile or handmade Suffolk pantile adds £250 to £600 per unit for the deep-profile or dressed lead flashing. Slate is slower and pricier than plain tile.
- Structural work. One rafter trimmed is priced in. Two or more, or a trussed roof, needs an engineer’s design and is quoted separately.
- Glazing. Triple glazing adds 15 to 25 per cent on the unit; solar control or a laminated inner pane adds £120 to £350.
- Internal finish. Splayed reveals, plasterboard and skim are itemised, included where stated in your quote.
Rooflights are only part of a loft conversion budget. These figures are for the rooflight installation, supplied and fitted. The wider conversion, floor strengthening, stairs, insulation, plastering and building control, is separate work by other trades. If the whole roof structure is being redesigned for the conversion, the rooflight openings become part of that structural design, covered on forming the structural opening, and we coordinate the glazing around it.
Escape units and cost
The single biggest thing that can lift a loft rooflight cost is the escape requirement. Where a conversion does not provide a protected stairway route, Part B requires an escape window with a clear openable area of at least 0.33m², a minimum clear opening of 450mm in both height and width, and the bottom of that opening no more than 1100mm above the floor. That rules out a standard centre pivot, whose pivot bar obstructs the opening, and it rules out the smallest units, which cannot reach 0.33m². So the escape room gets a top-hung escape unit at the upper end of the range, and there is no cheaper legal option. The escape rules in detail are on loft rooflight fire escape regulations. Better to budget for it than to fit a cheaper unit that Building Control then rejects.
Where it is cheaper, and where it is not
A loft conversion rooflight is cheaper where the room needs only daylight, not escape, so a centre pivot serves; where the covering is slate or plain tile rather than deep pantile; and where the units drop between or across rafters with minimal cutting. It is dearer where an escape unit is required, where the roof is deep pantile needing dressed lead, and where a trussed roof forces a structural design. We measure the actual rafters at survey and show you the options and their prices, so you can trade a slightly smaller, better-landing unit against a larger one that needs more cutting. The comparison of coverings on cost is on does fitting cost more on slate than tile.
Common questions about loft conversion rooflight cost
How much does a loft conversion rooflight cost?
Roughly £1,900 to £3,100 per unit supplied and fitted in the Ipswich and Suffolk area, including the flashing kit, both collars and trimming one rafter. An escape unit sits at the upper end. A common two-unit loft scheme runs around £3,400 to £4,700 in total, because the second unit shares the scaffold and set-up. The figure moves with unit size and type, the covering, and any escape requirement.
Is it cheaper to fit two rooflights at once?
Per unit, yes. The second unit on the same slope shares the scaffold, the set-up and the survey, so a two-unit scheme costs less than two separate jobs. A pair of 780 x 1180mm units runs around £3,400 to £4,700 together, against roughly £3,800 to £5,300 as two standalone jobs. Two units also light a room better than one, so it is usually the better spend as well as the cheaper way to buy the second.
Why does an escape rooflight cost more?
Because Part B requires a top-hung escape unit with a clear openable area of at least 0.33m², which rules out a cheaper centre pivot and the smallest units. There is no cheaper legal option for a room that needs escape, so it sits at the upper end of the range. It is worth budgeting for, because Building Control will reject a unit that does not meet the clear opening, and refitting is dearer than getting it right first.
Get your loft rooflights priced
Tell us the room’s rough size, what the roof is covered with, and whether it needs a fire escape window, and we will survey from inside the loft, work out the units the room needs and give you one written fixed price with everything itemised. Every installation carries a 10-year workmanship guarantee and the installers have 25 years fitting rooflights behind them.
Request a fixed quote for loft conversion rooflights in Ipswich, Suffolk or north Essex, or read our published prices across every service first.
Thinking about this job? We survey across Ipswich, Suffolk and north Essex and give you a fixed price before any work starts, with a 10-year workmanship guarantee.