Guide prices
Small sealed unit
Misted or cracked unit up to about 1 m² measured, made and refitted
Medium sealed unit
Units up to about 2 m², or toughened and laminated
Large or specialist
Triple glazed, solar-control or heavy units needing lifting gear
Guide ranges. The first visit is charged and priced before booking; any new glass is priced in writing before work starts. Scaffold, access towers or a crane are priced separately if the job needs them, and building control fees, where a job needs them, are shown as their own line.
Covering SM5 and neighbouring districts
Looking at a property near Carshalton but not quite in it? We work across SM5, SM1 and SM6 and outwards to Wallington, Sutton and Mitcham. Give us the full postcode when you get in touch, because access, parking and the route for a large unit all depend on the exact street. Those details shape the quote for any job around Carshalton.
What the job includes
- Sealed unit ordered to match or improve on the original glass
- New glazing tapes, gaskets or sealant fitted to suit the frame
- Joints water tested and the glass cleaned inside and out
- Matching the glass make-up — We identify the existing glass so the replacement performs at least as well.
- Condensation or a failed seal — We confirm whether the mist is inside the sealed unit or on the room-side surface.
How the glass is replaced
On the fitting visit, the room below is protected first. The beads or cappings come off, the old unit is lifted out with suction lifters, and the rebate is cleaned and checked for damage or blocked drainage. The new sealed unit goes in on fresh packers and gaskets, the cappings are refitted and sealed, and the glass is cleaned. Most glass swaps take half a day once the new glass is made.
Planning, building control and Carshalton
England's rules in short: permitted development usually covers a rooflight on a house roof provided it doesn't stick out more than 0.15 m or rise above the ridge, though a listed building always needs consent and some streets have Article 4 directions. Building regulations apply to new openings, and replacements go through building control; as we are not registered with a competent person scheme, we use a building notice and show the fee on the quote. The energy limit for rooflights in existing homes is 2.2 W/m²K, and the 2026 Approved Document L, in force from 24 March 2027, keeps that figure.
What to send us
Photos of the problem glass from inside and out, a rough width and length, and whether the rooflight opens or is fixed are enough to price the first visit. Add the postcode and how the roof is reached, and tell us if more than one unit has misted.
Common questions in Carshalton
Can you replace just the glass in my rooflight?
Often, yes. If the frame, gaskets and drainage are sound, a new sealed unit can go into the existing frame. If the frame has failed, is distorted or leaks around the edge, replacing the whole rooflight is usually the better answer, and we tell you that.
Is new glass or a new rooflight better value?
If the frame, gaskets and drainage are sound, new glass is usually the cheaper fix. If the frame is cracked, distorted or leaking at the kerb, a full replacement is better value. After the measuring visit we price both so you can compare.
How long does new rooflight glass take?
The new sealed unit is made to the measured size, so there is a gap between the measuring visit and the fitting visit while it is produced. We give you the expected timing when we price the glass, and book the fitting once it has arrived.
For a repair in Carshalton, start with photos and the postcode; we confirm the visit price before anything is booked.

