Caernarfon · Gwynedd & Anglesey
Glass Roofs in Caernarfon
We cover Caernarfon and the rest of Gwynedd & Anglesey for structural glass roofing, from single frameless rooflights to full side-return and rear extension roofs.
- LL55
- Guide from £1,095 per m²
Caernarfon: structural glass roof
Glass roofs are heavy and the units are large, so installation often needs cranes, glass lifting robots or vacuum lifters, and sometimes road or pavement access arrangements. Access is planned at survey, because it can influence the maximum panel size and the installation day.
Overhead glass in a glass roof is generally specified with a laminated inner pane. If the inner glass breaks, the interlayer holds the fragments together instead of letting them fall into the room. BS 5516-2 is the British Standard code of practice for sloping and overhead glazing.
Fixed frameless rooflights sit on a flat roof upstand with the glass edge overhanging the kerb, so from inside you see only sky and plaster. The upstand must be level, insulated and weathered into the roof covering, and the roof needs a fall so water drains off the glass.
A new glass roof or walk-on panel is building work that normally needs building regulations approval through building control, covering structure, energy performance and, close to a boundary, fire performance. Planning permission may also be needed depending on the extension and the property, so check with the council.
What a typical job includes
- Lifting, positioning and fixing of every glass unit
- Glass specification with laminated make-up and coatings
- Site survey and structural assessment of supports
- Weather sealing of joints, edges and upstands

Working in Caernarfon
- Postcodes covered
- LL55 and the surrounding area, including Bangor (Gwynedd), Pwllheli and Holyhead
- Coast
- Caernarfon is about 2 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. Glass roofs near the coast collect salt film that self-cleaning coatings may not fully remove, so occasional rinsing helps. Exposed sites face higher wind uplift, which affects glass thickness and fixings, and any metal supports need coatings or grades suited to salt air.
- Daylight and sun
- In Caernarfon the midwinter sun reaches about 13° above the horizon at noon, with roughly 7.3 hours of daylight, rising to about 60° and 16.7 hours in midsummer. Overhead glass admits far more daylight than vertical glazing, especially in summer when the sun is high. South-facing glass roofs usually need solar-control coatings or fritting, while north-facing roofs can use clearer low-E glass to maximise winter light.
- Access and setting
- Rural sites may have long or narrow access tracks that limit crane positions and panel sizes, so access is surveyed early. Exposed locations face higher wind and snow loads, and leaves and debris from nearby trees mean gutters need regular clearing.
- Rules in Wales
- In Wales, Approved Document N covers safety glazing: safety glass is needed in and around doors and in low-level glazing where people could walk into it.
Guide prices in Caernarfon
| Typical job | Guide price inc VAT |
|---|---|
| Frameless glass roof, per m² | £1,095 – £1,795 |
| Walk-on glass panel, per m² | £1,495 – £2,395 |
Get a guide price for your size
Like-for-like replacement windows on houses in Wales are usually permitted development, but flats, listed buildings and conservation areas can need permission. Check with the local planning authority.
Options to choose between
Side-return glass roof
Large glass units spanning from the house wall to the boundary, supported on glass beams or slim steel, for extended kitchens.
Fixed frameless rooflight
A flat glass unit bonded to a minimal edge frame on an upstand, giving an unbroken view of the sky from inside.
Glass floor panel
Laminated glass floor sections that let light through to a basement or lower floor, supported on a level, engineered frame.
Glass Roofs in Caernarfon: questions
How do you stop a glass roof leaking?
A glass roof stays watertight through a fall that lets water run off, weather seals and structural silicone joints between panes, well-detailed flashings at walls and upstands, and clear gutters or outlets. Most leaks start at flashings or blocked drainage rather than the glass. Annual checks of joints and outlets prevent most problems.
How much does a glass roof cost?
The cost of a glass roof depends on the area of glass, the size of each unit, the glass make-up and coatings, the support beams or framing, the structural design and the access for lifting. Walk-on and very large panes cost more because of their thickness. See the guide prices for typical ranges; the written quote fixes the price.
How is a glass roof installed?
A glass roof is installed onto supports already built and checked, such as walls, steel beams, glass beams or upstands. The glass units are lifted with a crane, glass robot or vacuum lifters, set onto gaskets or setting blocks, fixed and then weather sealed. Most domestic roofs are installed in a day or two once supports are ready.
Is a glass roof safe if the glass breaks?
A properly specified glass roof is designed so that a broken pane stays in place. The inner pane is laminated, so fragments remain bonded to the interlayer instead of falling into the room. The glass thickness, supports and edge details are designed for the expected loads, including snow, wind and maintenance access.
Do you cover Caernarfon for glass roofs?
Yes. We can quote for glass roofs across Caernarfon and the surrounding Gwynedd & Anglesey area, including postcode districts LL55, and nearby Bangor (Gwynedd), Pwllheli and Holyhead. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in Caernarfon
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.