Skylight replacement for Porthmadog: the essentials
Thinking about skylight replacement in Porthmadog? The short answer: replacing tired domes and failed glass with a modern rooflight. The longer answer depends on your roof, which is why we survey before we price.
Wales sees a lot of wind-driven rain, particularly in the west, so upstand height and flashing laps matter more than anywhere. Think of skylight replacement for older extensions due a modern rooflight.
Porthmadog sits about 19 km from Pwllheli and 25 km from Caernarfon, and we cover the whole LL49 postcode district and the roads in between.
What you can choose
- Like-for-like size replacement
- Roof window replacement in pitched roofs
- Dome to flat glass upgrade
- Upstand rebuild and insulation
- Fixed to electric opening
- Better thermal performance
- Cures most chronic leaks
Things we check at survey
- A replacement is a chance to meet current thermal standards
- Upstand and roof condition decide the scope
Do you need permission in Porthmadog?
In Wales a rooflight on a house is usually permitted development if it stands no more than 15 cm proud of the roof, except on protected land such as conservation areas and National Parks, where permission is needed. Listed buildings need listed building consent from the council, and flats have no householder permitted development rights.
Welsh Building Regulations expect new or replacement rooflights to reach 2.2 W/m²K and roof windows 1.4 W/m²K or a Band B rating. A revised Welsh Approved Document L takes effect on 4 March 2027; rooflights in new dwellings stay at 2.2 W/m²K.
Our planning guide covers each nation in more detail.
What does skylight replacement cost in Porthmadog?
These are typical supply-and-fit ranges. For an address in Porthmadog, scaffold, a hoist for heavy glass, or a new structural opening can move the figure, which is why we survey first.
| Option | Guide price inc VAT | Ex VAT |
|---|---|---|
| Replacement with upstand rebuild and opening unit | £2,995 – £4,795 | £2,495 – £3,995 |
| Dome to flat glass upgrade Typical | £1,915 – £2,995 | £1,595 – £2,495 |
| Like-for-like glass rooflight | £1,555 – £2,155 | £1,295 – £1,795 |
How the job runs
- Get in touch. Use the form, WhatsApp or the guide-price tool with your Porthmadog address.
- Measure and check. A surveyor visits Porthmadog, measures and checks structure and access.
- Fixed quote. Product, work and price in writing — nothing is ordered until you agree.
- Fit and make good. We fit, seal, test and finish the reveal, then hand over the paperwork.
Nearby towns
Other services in Porthmadog
Common questions
Can you replace only the misted glass?
Sometimes, if the frame is sound and the maker supplies replacement units. Often a complete new rooflight costs little more and performs better.
What do you do with the old unit?
We remove it from site and recycle what can be recycled.
Will it mess up my ceiling?
We protect the room and make good the reveal. Minor decoration may be needed afterwards.
Do I need to be at home for the survey in Porthmadog?
Yes — someone needs to let us into the room below and, where possible, show us how the roof is reached.
Is the survey in Porthmadog free?
Yes for new installations. Repair visits are charged, and we tell you the price before we book.
