Guide prices in Welwyn Garden City
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 AL8 and neighbouring districts
Fitters travel to the job, so the address is what counts. In Welwyn Garden City that means postcode districts AL8, AL7 and AL6, and the same teams can just as easily take on work in Hatfield, about 3 miles away, or Hertford at roughly 6 miles. Survey and fitting dates are offered according to fitter availability, and travel is built into the quote rather than added later.
What the job includes
- Sealed unit ordered to match or improve on the original glass
- Measuring visit to size the glass and identify its make-up
- New unit set on packers, then beaded, capped or bonded as designed
- Weight and lifting — We plan how a heavy pane gets onto the roof and into the frame.
- Matching the glass make-up — We identify the existing glass so the replacement performs at least as well.
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.
Regulations for Welwyn Garden City properties
Two sets of rules matter in England. Planning: a rooflight on a house is normally permitted development if it projects no more than 0.15 m and stays below the highest part of the roof, but flats, listed buildings and Article 4 areas need checking. Building regulations: new openings need approval for the structure and energy performance, and a replacement is a controlled fitting. We are not registered with a competent person scheme, so we notify replacements to building control with a building notice and put the council's fee on the quote.
What to send us
To price the measuring visit, send a photo of the rooflight from inside showing the misting or crack, one from outside if you can reach a safe viewpoint, and the rough size of the glass. If you know the make or have the original paperwork, include that too, along with the postcode.
Common questions in Welwyn Garden City
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.
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.
Can I upgrade the glass while it is being replaced?
Usually. Solar-control, self-cleaning, toughened or laminated glass can be specified as long as the frame can take the thickness and weight. We check that on the measuring visit and price the options side by side.
Got a leak or a misted unit in Welwyn Garden City? Send photos first and we will tell you what the visit costs before booking.

