An energy efficient rooflight, supplied and fitted with a solar control double-glazed unit, a warm-edge spacer, a new insulated upstand and airtight detailing, runs from roughly £1,400 for a small pitched roof window up to £6,000 for a large roof lantern in Ipswich and Suffolk. Stepping up to triple glazing adds several hundred to a couple of thousand pounds depending on size. The insulated upstand is where a lot of the real value sits, and a preformed insulated kerb over a site-built timber one adds £250 to £600. No other installer in Suffolk publishes these figures. We do, because three quotes with no common basis is not a comparison.
This page sets out the cost steps between standard, high-performance and triple specifications, and the upstand premium, so you can budget the upgrade honestly before you take quotes.
The installed price by size
The ranges below are supply and fit, in the Ipswich, Suffolk and north Essex area, for a thermally broken unit with argon-filled double glazing, a warm-edge spacer, a solar control coating where orientation calls for it, a new insulated upstand, airtightness and vapour control detailing, weathering and internal trims. Single storey, reasonable access, sound structure.
| Unit and size | Double glazed, supply and fit | Triple glazed, supply and fit | Days on site |
|---|---|---|---|
| Pitched roof window, 780 x 1180mm | £1,400 to £1,900 | £1,850 to £2,500 | 1 |
| Pitched roof window, 1140 x 1180mm | £1,700 to £2,300 | £2,250 to £3,000 | 1 |
| Flat rooflight, 1.0 x 1.0m | £2,100 to £2,900 | £2,700 to £3,600 | 1 to 2 |
| Flat rooflight, 1.5 x 1.0m | £2,600 to £3,500 | £3,300 to £4,400 | 2 |
| Flat rooflight, 2.0 x 1.2m | £3,300 to £4,500 | £4,200 to £5,600 | 2 |
| Roof lantern, 2.5 x 1.5m | £4,600 to £6,000 | £5,600 to £7,400 | 2 to 3 |
The three glazing steps and what each buys
Think of the glazing spend as three steps, not a single price. Each step buys a specific thing, and it is worth knowing what.
| Step | Whole-unit U-value | What you get | Where it is worth it |
|---|---|---|---|
| Standard: clear double, argon, warm-edge | 1.3 to 1.5 | Comfortable baseline, high daylight | North-facing, shaded, daylight-critical rooms |
| High-performance: solar control double | 1.2 to 1.4 | Overheating control plus slightly lower U-value | South and west facing and all flat rooflights |
| Triple: clear or solar control | 0.7 to 1.1 | Lower heat loss, warmer inner glass, less downdraught | Large units, north-facing, low-energy builds |
The step from standard to high-performance solar control is usually modest per unit and often the right call, because it fixes summer overheating as well as trimming the U-value. The step from double to triple is the larger one, and it is right less often than the marketing suggests. We weigh that decision on double or triple glazed rooflights, what the numbers say, and the direct pricing is on how much a triple glazed rooflight costs.
The insulated upstand premium, and why it is worth paying
The upstand is where a good rooflight is made or ruined, and it is a real line in the budget rather than an afterthought. A bare timber upstand is cheap and it is exactly what causes the cold, mouldy reveals we are called to fix, as set out on thermal bridging at rooflight junctions. Building it properly costs money, and it is money that prevents a far larger bill.
- Preformed insulated upstand instead of a site-built insulated timber upstand: add £250 to £600. On a flat roof it is often the better detail as well as the quicker one, because it takes the timber out of the thermal path in one component.
- Rebuilding a failed upstand rather than reusing a sound one: add £400 to £900, depending on size and what the timber looks like underneath.
Spend on the junction before the third pane. If the budget is finite, an insulated upstand under a good double unit outperforms a triple unit on a bridged timber upstand, every time. That is not a slogan, it is the order in which the heat leaves the building. The upstand also prevents the mould that costs plasterboard, decoration and eventually structural timber, which is a repair bill far larger than any plausible fuel saving.
What else moves the figure
- Local authority Building Control fee: stated separately, typically low hundreds for a rooflight or small structural opening, set by the council rather than by us. We handle the Building Control notification for you, so notifiable work is properly certificated and signed off, which is covered on meeting Part L with replacement rooflights.
- Structural engineer’s calculation where the opening is over 1.5m or the roof is an unknown quantity: a few hundred pounds, arranged separately, and the cheapest insurance on the job.
- Marine-specification coating and 316L stainless fixings: included as standard within about a mile of open sea at Felixstowe, Harwich or Frinton. Priced as an upgrade elsewhere.
- Electric opening vent with rain sensor: add £600 to £1,100 fitted, depending on system and how far the nearest power is. Covered on our electric skylight installation page.
- Replacing rotted deck found on strip: quoted at survey where it is visible, and where it genuinely is not visible until the covering is off, priced at a rate agreed in writing before we start rather than invented on the day.
Being straight about payback
You will see rooflight pages promising a payback period in years or a percentage saved on bills. We will not give you one, because we would be making it up. The heat saved depends on the size of the unit, the U-value it replaced, the heated volume behind it, your heating system and its efficiency, your fuel price and how warm you keep the house. Change any one and the answer moves by a wide margin. The honest ranking of benefit is comfort first, damp and mould prevention second, summer overheating control third, and fuel saving fourth. We set out how to estimate your own case, without invented figures, on whether new rooflights pay for themselves.
How much more does an energy efficient rooflight cost than a basic one?
The glazing uplift from a standard clear double unit to a high-performance solar control one is usually modest per unit. The larger cost is doing the whole job properly: a new insulated upstand, airtightness and vapour control detailing, add materially over a cheap swap that reuses a bare timber upstand. That is the money that prevents cold reveals and mould. On our quotes the specification and the upstand detail are itemised, so you can see exactly what the difference buys.
Is the price on the table what I will pay?
The table is a genuine range to help you budget, not a teaser. Once we have surveyed, you get one written price with the glazing specification and the declared whole-unit U-value on it, and that is the price you pay unless you change the specification. The Building Control fee, and any structural calculation, are stated separately rather than buried. Where hidden rotted deck cannot be seen until the covering is off, we agree a rate in writing before starting.
Get a fixed price with the specification on it
Tell us the room, roughly where the property sits, which way the roof faces, and whether this is a new opening or a replacement. We survey it and give you one written price with the whole-unit U-value, the g-value and the light transmission on it. That price is fixed. A 10-year workmanship guarantee, and installers with 25 years on rooflights.
Request a fixed quote, work through our published prices, or start from energy efficient skylight installation.
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.