In brief
The cost of a conservation rooflight is set by its size, its frame and glazing, the work needed to flash it into slate or tile, and how the roof is reached. A small unit in an easy slate roof is a different job from a wide one in an old roof that needs scaffolding. The price for your roof comes from a free survey, followed by a written quote listing the rooflight and everything it covers.
- Size: a wider and taller unit costs more to make, carry and fit
- Frame and glazing: slim frames, bars and the glass specification all move the price
- Roof covering: flashing into slate or clay tile takes care and time
- Access: scaffold, a tower or lifting gear for the glass
- The inside: lining the opening and any plastering or decorating
Why the same rooflight costs different amounts
A conservation rooflight is a low-profile unit, often with a slim metal frame, that sits close to the roof slope. It is a made-to-order product sold in a range of sizes, and the fitting depends on what it is going into. That is why two houses in the same street can be quoted differently for what looks like the same window.
The price has two halves. One is the unit itself, which comes from the maker and varies with the size, the frame and the glass. The other is the work on your roof: cutting the opening, trimming the rafters, flashing the unit into the covering, and finishing the reveals inside. We look at both before putting a figure in writing.
Our rooflight costs guide explains how the quote is built for every kind of rooflight, and this page covers what is particular to conservation units.
Size, frame and glazing
Size is the first factor. A larger unit is made from more glass and a longer frame, and needs more people to lift it into place. Conservation rooflights are made in a range of standard sizes, and some makers also build to a size you specify, which adds to the price and the lead time.
The frame is the second. Slim frames in steel or aluminium, in black or another finish, are part of what gives these rooflights their look. Whether the unit has a central glazing bar, and whether it is fixed or opens, changes the frame and the price. Our page on the central glazing bar explains when one is asked for.
The glass is the third. Double glazing is the normal specification and some makers offer triple. Coatings and finishes add to the price. See whether conservation rooflights are double glazed for what that means in a slim frame.
Slate, tile and the flashing
A conservation rooflight sits close to the roof surface, so the flashing around it must follow the covering neatly. In slate, the slates are lifted around the opening, the flashing is dressed in and the slates are relaid to meet it. In clay tile the process is similar, with each tile cut or reused to suit the line of the frame.
Old roofs add care. Handmade tiles and reclaimed slates are not easy to replace if they break, so the work goes more slowly and the covering may need a note in the quote for spare slates or tiles. Lead, where it is used, takes time to form.
A roof that is already in poor condition around the opening can add work before the rooflight goes in. We say so at survey rather than leaving it for the day.
Access and the inside finish
Access can be a large part of the price. A low roof reached from a garden might need only a tower. A tall terrace might need scaffolding to the eaves, and a large unit might need lifting gear. The quote tells you what access has been allowed for.
Inside, the opening needs to be lined and finished. In a loft or attic, that may mean boarding, insulating the reveals and plastering, with your plasterer or ours. If the room has period features such as beams, the reveals are shaped to suit. We agree who does which trade so that nothing is done twice.
If an electric unit or reveal lighting is wanted, the electrician does a first fix before the plaster goes on, and that is planned into the same sequence.
Planning and consent affect the specification
In a conservation area, a National Park or on a listed building, the council may ask for a particular style of rooflight, and that can change what is quoted. A required glazing bar or a specific finish is part of the specification, not an extra at the end.
We look into the position for the property and report back; the decision belongs to the council. For the rules, see rooflights in conservation areas, listed building consent for a rooflight and our planning guide.
Application fees are set by the council and sit outside our quote.
How the written quote works
Book a free survey. We look at the roof, the covering, the structure and the room, and agree the unit with you. The written quote then spells out which rooflight is being fitted, what glass it has, when the maker expects to deliver it and the jobs your builder must finish first.
Your builder or architect is handed the kerb or opening dimensions ahead of construction, so the structure is cut to suit the actual rooflight. On a larger project we place the order so that the glass arrives as the roof nears completion.
The maker decides how long delivery takes, and the quote states it. You can find more on the range on the conservation rooflights hub, and on choosing between types in conservation rooflight or standard roof window.
Related questions
- Can I get a conservation rooflight fitted as part of a loft conversion?
- Yes. When the roof is being built or altered anyway, the opening, the flashing and the lining can be planned with the roofer and plasterer, which avoids opening up a finished roof later. Send us the drawings and we can price from them.
