Fishguard · Dyfed
Roof Lanterns in Fishguard
Old polycarbonate lanterns in Fishguard that leak, rattle or have yellowed can usually be replaced with a double glazed aluminium lantern on a sound upstand.
- SA65
- Guide from £1,095
Opening skylights for homes and businesses in Fishguard
Old polycarbonate or single glazed roof lanterns can be replaced with double glazed aluminium lanterns on the existing upstand, if the upstand is sound, level and the right size. Upstands that are rotten, uninsulated or out of level should be rebuilt first, which the survey identifies.
The price of a roof lantern or skylight depends on the size and shape, glass specification, frame colour, opening vents or electric operation, and whether the upstand already exists or needs building. Access to the roof and lifting large units add labour. See the guide prices for typical ranges.
Cutting a new opening for a roof lantern or skylight usually means trimming joists or rafters, so the roof can carry the load around the hole. Building regulations approval is generally needed for a new rooflight, covering structure, energy performance and, near a boundary, fire performance.
Warm, moist air rises and collects in a roof lantern, so condensation can form on cold winter mornings, especially over kitchens and bathrooms. Thermally broken frames, warm-edge spacers and good room ventilation reduce it, and opening vents in the lantern can release warm air in summer.
What's included
- Written guarantee terms and manufacturer documentation
- Survey of the roof, opening, upstand and drainage
- Fixing, glazing and sealing onto the prepared upstand
- Sealed double glazed units with laminated inner pane options

Local details for Fishguard
- Postcodes covered
- SA65 and the surrounding area, including Haverfordwest, Cardigan and Milford Haven
- Coast
- Fishguard is about 2 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. Coastal lanterns face salt deposits on the glass and frames and strong uplift from wind on exposed roofs. Marine-grade coatings, stainless fixings and secure fixing to a well-built upstand matter, and salt film may need rinsing more often than self-cleaning glass manages alone.
- Daylight and sun
- In Fishguard the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.5 hours of daylight, rising to about 61° and 16.5 hours in midsummer. Overhead glazing receives far more light than a wall window of the same size, especially when the sun is high in summer. South-facing lanterns may need solar-control glass, while low winter sun and north-facing rooms benefit from clear, high light-transmission low-E glass.
- Access and setting
- Rural roofs collect more leaves, moss and bird debris, so lanterns need clear upstand drainage and regular checks. Exposed sites see higher wind loads and driving rain, and older outbuildings may need the roof structure strengthening before a lantern is added.
- 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 Fishguard
| Typical job | Guide price inc VAT |
|---|---|
| Lantern 1500 × 1000 mm, fitted to a kerb | £1,395 – £1,795 |
| Lantern 2000 × 1000 mm | £1,695 – £2,095 |
| Lantern 3000 × 1500 mm | £2,795 – £3,695 |
| Flat glass rooflight 1000 × 1000 mm | £1,095 – £1,395 |
Get a guide price for your size
Welsh ventilation guidance expects replacement windows not to reduce background ventilation, so trickle vents are often included.
Specification choices
Rectangular hipped lantern
A long ridge with hipped ends, suiting most rectangular extensions and kitchens, sized to the opening and the room below.
Opening vents
Manual or electric vents in the lantern or skylight, with optional rain sensors that close them automatically in wet weather.
Square or octagonal lantern
A pyramid or eight-sided design that suits square rooms, orangeries and spaces where a central focal point is wanted.
Roof Lanterns in Fishguard: questions
Should the inner glass in a roof lantern be laminated?
Laminated inner glass is the safer choice and is recommended by the Rooflight Association. If a laminated pane breaks, the interlayer holds the pieces together, so glass is far less likely to fall into the room below. This matters most over kitchens, dining tables, stairs and seating, and it is offered as a standard option.
How much does a roof lantern cost?
The cost of a roof lantern depends on its size and shape, the glass specification, frame colour, any opening vents, and whether the upstand exists or needs building. Access to the roof and lifting a large lantern also affect labour. See the guide prices for typical ranges; the written quote fixes the price for your exact specification.
Why does my roof lantern get condensation?
Condensation forms when warm, moist air from cooking, bathing or drying clothes meets the colder glass and frames at high level. Older single glazed or non thermally broken lanterns suffer most. Thermally broken frames, warm-edge spacers, extractor fans and opening vents reduce it. Some condensation on very cold mornings is normal and clears as the room warms.
Can I replace my old polycarbonate roof lantern with glass?
Yes, in most cases. A glass lantern is heavier than polycarbonate, so the upstand and roof structure must be able to carry it. If the upstand is sound, level and the right size, a new aluminium lantern can usually sit on it. If not, the upstand is rebuilt first, which the survey will identify.
Do you cover Fishguard for roof lanterns?
Yes. We can quote for roof lanterns across Fishguard and the surrounding Dyfed area, including postcode districts SA65, and nearby Haverfordwest, Cardigan and Milford Haven. 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 Fishguard
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.