How Much Does a 1m x 1m Flat Rooflight Cost Fitted?
A 1m by 1m flush glass flat rooflight fitted into a new opening costs £2,200 to £3,000 in the Ipswich, Suffolk and north Essex area, supply and fit, on a single-storey flat roof with reasonable access and sound structure. A like-for-like replacement of an existing unit into a sound kerb is less, from around £1,650 for that size, because there is no structural opening to cut. The figure covers a thermally broken flush glass unit with solar control double glazing, a new insulated kerb, all fixings, weathering and internal trims. What moves it is the kerb condition on a replacement, correcting the falls, glazing upgrades and access.
Below is the worked breakdown so you can see what each part costs and check any quote against it. The full cost structure across all sizes is on flat roof rooflight installation cost, and the wider job on flat roof skylight installation.
The worked breakdown
Taking a new opening in a sound roof, a 1m by 1m flush glass unit breaks down roughly like this. The figures are indicative bands within the total, not a fixed price list, and they overlap because jobs vary.
| Component | Indicative band | What it covers |
|---|---|---|
| The unit | £700 to £1,100 | Thermally broken flush glass, solar control double glazing, made to size |
| Kerb works | £350 to £550 | New insulated timber kerb, braced, ply-faced |
| Structural opening | £300 to £500 | Trimming the joists around a 1m opening, standard trimmers |
| Weathering in | £300 to £500 | Dressing the covering up and over the kerb in the matching system |
| Internal finishing | £250 to £450 | Forming and splaying the reveals, plasterboard and trims |
| Access and setup | £150 to £300 | Tower, edge protection, disposal on a single-storey roof |
Bands overlap and are indicative. The survey confirms one fixed figure inside the £2,200 to £3,000 total. Internal finishing scope varies, so check whether a quote includes it.
The assumptions behind the figure
A price only means something with its assumptions stated. This one assumes:
- A single-storey flat roof reached with a tower and edge protection, not full scaffold.
- Sound structure, so a 1m opening is carried by standard doubled trimmers with no engineer’s calculation needed.
- A roof that drains, so no falls correction is required. If it ponds, correcting the fall is extra.
- A sound covering to dress into, not a membrane at end of life needing a recover.
- Double glazing with solar control, thermally broken frame. Triple glazing adds 15 to 25 per cent on the unit.
- Inland exposure. Coastal work at Felixstowe adds the marine specification, included as standard there.
Replacement against new opening
The same 1m by 1m unit costs less to fit into an existing opening than a new one, because the structural component disappears. A like-for-like replacement into a sound kerb has no joists to cut and trim, so it starts around £1,650 for this size. What a replacement adds instead is the kerb unknown: on a 1980s or 1990s dome the timber underneath is often soft, and a kerb rebuild is a provisional £350 to £900 confirmed once the old unit is off. So a replacement into a good kerb is the cheapest version of this job, and a replacement into a rotten kerb creeps toward the cost of a new opening.
One fixed figure after survey. The £2,200 to £3,000 band is genuine, not a teaser. Once your roof is surveyed you get one written price inside it, and that is what you pay, with only a kerb rebuild left provisional on a replacement until the old unit is off.
What pushes a 1m job up or down
- Down: a like-for-like replacement into a sound kerb, easy access, an existing sound covering, and finishing done by your own plasterer.
- Up: a rotten kerb to rebuild, falls to correct, an opening upgrade, triple glazing, an electric opener, restricted or two-storey access, or a covering at end of life needing a recover.
The single biggest swing on a replacement is the kerb. On a new opening it is whether the structure and covering are as expected. Neither is a surprise if the survey is done properly, which is why we check the fall on all four faces and probe the kerb before quoting.
Suffolk and north Essex specifics
The 1m by 1m size is the workhorse of flat rooflight work locally, going into side-return kitchens, rear extensions and utility rooms across Ipswich, and replacing the 900 by 900mm domes on the estate garages at Kesgrave, Rushmere and Chantry. On those older jobs the kerb is the variable to watch. On the coast at Felixstowe and Harwich the same unit takes the marine specification, 316L fixings and marine-coated frame, which is included in the coastal price rather than added. Estuarine areas such as Woodbridge get upgraded fixings without the full marine package.
Common questions
How much is a 1m x 1m flat rooflight fitted?
£2,200 to £3,000 for a flush glass unit in a new opening in Suffolk, supply and fit, on a single-storey roof with sound structure and access. A like-for-like replacement into a sound kerb starts around £1,650, because there is no opening to cut. The survey confirms one fixed figure inside those bands.
Why is a replacement cheaper than a new opening?
Because the structural work disappears. A new opening means cutting and trimming joists, a replacement drops into an opening that already exists. What a replacement adds instead is the kerb unknown, which on an old dome is often a provisional £350 to £900 rebuild confirmed once the unit is off.
Does the price include the plastering?
It depends on scope. Some quotes hand over with the unit fitted and the reveals ready for your own plasterer, others include finishing to a painted reveal. A quote that excludes finishing is not comparable with one that includes it, so it is worth checking. Our breakdown shows finishing as a separate band so you can see it.
Get a fixed price for a 1m rooflight
Tell us whether it is a new opening or a replacement, the existing covering if you know it, and where the property sits. We will survey it, check the fall and the structure, and give you one written fixed price inside the band above with the glazing specification and U-value stated. Every installation carries a 10-year workmanship guarantee.
Request a fixed quote in Ipswich, Suffolk or north Essex, or see the cost of replacing several rooflights if you have more than one.
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.