The short answer
Yes. A solid tiled conservatory roof can take roof windows, and they bring daylight back into the room. A roof window is a framed window set into the slope, and under Part L of the Building Regulations a roof window follows the window row, 1.4 or Band B. A rooflight, a different product, follows 2.2. Ask building control how both apply.
Roof windows are the usual answer to a darker room under a solid roof. The thermal figures, the frame and the sign-off all matter.
Roof windows in a solid roof
A solid conservatory roof is built like a small pitched roof: rafters, insulation, battens, tiles and a ridge. Roof windows are framed into that structure, so the rafters are trimmed around each opening and a flashing kit, a set of pre-formed metal pieces, is dressed around the frame to keep water out.
Where do they go?
The best positions are high enough on the slope to throw light deep into the room, and clear of the wall junction and the ridge. Spacing them so each sits between rafters avoids cutting more of the structure than necessary. Opening ones also give you ventilation on hot days, which the room often needs once the glazed roof has gone, because warm air leaves at the top of the room and a fixed pane never lets it. A roof window in the standard mid-range costs £1,100 in MyJobQuote's guide (Sep 2026), before any structural work around it. Blinds are worth pricing at the same time on a south-facing slope, so the room stays usable in a heatwave. Ask the supplier for the flashing kit that matches your tile profile, because a mismatched kit lets water in at the corner.
The framing around each opening is what makes this a roofing job as much as a glazing one. Our answer on whether a solid roof makes a conservatory dark sets out how many windows the room is likely to want.
The Part L figures, stated correctly
Part L of the Building Regulations covers the conservation of fuel and power. Approved Document L, Volume 1, 2021 edition with 2023 amendments, takes effect from 15 June 2022 and sets values for new elements in existing dwellings in Table 4.2.
What is a roof window, and what is a rooflight?
The two are not the same product and they do not share a figure. Table 4.2 puts roof windows in its window row, with a limit of 1.4 or a Band B rating. Rooflights have their own row at 2.2. So a roof window in a solid roof is judged on the window figure, and a flat glazed rooflight on the higher one. The roof itself has 0.15 in the same table.
Those figures are for the 2021 edition. From 24 March 2027, AD L 2026 takes effect, with the tables renumbered 3.2 and 3.3. Until then, the 2021 tables are the ones to cite. Treat the numbers as a guide and put the question to your building control body, naming the roof and the windows, before you order.
Building Regulations and consent
Planning Portal guidance on conservatories is that a replacement roof has to satisfy the Building Regulations, covering structure, energy performance and ventilation. A solid roof with windows is a new roof, so expect to deal with building control for it.
Who do I ask?
For a Somerset address, Somerset Building Control handles the former Taunton and West area and the rest of the county, on 0300 303 7790. Rather than hunting for a percentage, put your actual roof to them: the structure, the insulation, the windows and the junction with the house.
Planning is a separate question. A listed house needs listed building consent where the work affects it, and for a conservation area or a listed Article 4 direction you should speak to Somerset Council's planning team. Inside the Exmoor National Park, Exmoor National Park Authority is the planning authority. Our answer on whether a solid roof turns a conservatory into an extension looks at the wider building control question.
What decides the job and the price
The number of windows, their size, the pitch, the height of the ridge and how much rafter work each opening needs all move the price. So does access: a roof high above a patio needs more planning than one low over a lawn.
How do I plan the windows with the roof?
Decide on the roof and the windows together, not one after the other. Cutting an opening in a finished solid roof means opening the tiles, the insulation and the ceiling again. Done as part of the build, it is one set of works and one set of flashings.
We look at the room from inside, check which way it faces and where the light is needed, and give one written total price covering the roof and the windows we agreed. Send us the room dimensions and a picture of the existing frame, and we will say what looks workable. Our conservatory roofs page covers the three coverings and how to choose between them.
More on windows in a tiled conservatory roof
Do roof windows leak in a conservatory roof?
A properly flashed roof window should stay watertight, because the leaks that do happen come from poor flashings and badly lapped tiles around the frame, not from the window itself. That is why the opening is framed into the rafters and flashed as part of the roof, rather than cut in afterwards.
Do roof windows and rooflights share a thermal figure?
No. In Approved Document L, a roof window follows the window figure of 1.4 or a Band B rating, and rooflights follow a separate figure of 2.2. Check which product your supplier is selling, then ask building control which figure applies to your conservatory roof before you order.
The full picture: Conservatory roofs in Taunton · More short answers