- Guide price
- £700–£1,150
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Merthyr Tydfil at a glance
- Largest towns
- Merthyr Tydfil, Treharris
- Postcode areas
- CF
- Building control
- Merthyr Tydfil County Borough Council
- Neighbouring areas
- Rhondda Cynon Taf · Blaenau Gwent · Caerphilly · Torfaen
- Guide price region
- Wales (−8% on West Midlands rates)
How much does a porch or bay roof cost in Merthyr Tydfil?
Guide prices including VAT at Wales rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Porch or bay (4 m²), EPDM | £700–£1,150 |
| Single garage (18 m²), EPDM rubber | £1,450–£2,600 |
| Extension (20 m²), GRP, new deck + insulation | £2,750–£4,950 |
Which flat roofs are common in Merthyr Tydfil?
Flat roofs in Merthyr Tydfil sit on bungalows with flat-roofed side extensions and dormers, lock-up garage blocks on estates and terraced streets with flat-roofed rear kitchens and bathrooms. Wales averages roughly 1,460 mm of rain a year, among the wettest in Britain, so we design for steady run-off: proper falls, clear outlets and upstands well above the finished roof. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in Wales
Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. Renovated roofs are upgraded to around 0.16 W/m²K where feasible, and new extension roofs are built to 0.13 W/m²K under the Welsh Approved Document L. In Merthyr Tydfil the application goes to Merthyr Tydfil County Borough Council. More on the rules.
Which material looks best on a porch or bay roof?
For most porches, EPDM rubber gives a neat, dark grey finish that sits quietly on the front of a house, and on a small roof it can usually be laid as one piece. For angled bays and curved canopies, GRP fibreglass or a liquid-applied system follows the shape without folds or joins.
Many older bay windows and porches were finished in lead, which has a distinctive look. Where you want to keep that appearance, especially on a period house, we can discuss a lead-look finish or retaining lead flashings at the wall. On a listed building or in a conservation area, changing from lead to a membrane may need consent, so we check that at survey.
Colour matters more here than on a hidden rear roof. GRP topcoats come in several colours, and EPDM is typically black or dark grey.
Do I need permission to re-roof a porch or bay?
Usually not. Re-covering a porch or bay roof without materially changing how it looks does not normally need planning permission, and an unheated open porch is not usually a thermal element.
The picture changes if the bay or porch is part of a heated room: replacing most of the roof can then bring it under the insulation rules for renovated roofs, which may need building control approval in England, a check in Wales, building standards in Scotland or district council building control in Northern Ireland. On a very small roof, adding insulation may not be technically feasible because of the height available below the window sill above. We assess that at survey.
Listed buildings need consent for changes that affect their character, and conservation areas can restrict changes to the front of a house. See our building regulations page for more detail.
Which towns in Merthyr Tydfil do we cover?
Porch, bay and canopy roofs in Merthyr Tydfil: questions
Which towns in Merthyr Tydfil do you cover?
All of Merthyr Tydfil. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a porch or bay roof cost in Merthyr Tydfil?
£700–£1,150 for a small 4 m² porch or bay roof in EPDM, at Wales guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which council handles building control for a flat roof in Merthyr Tydfil?
It depends on where the roof is: in Merthyr Tydfil that's Merthyr Tydfil County Borough Council. Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. We confirm which applies at the survey.
Can a bay window roof be replaced without scaffold?
A ground-floor bay usually can, using a tower or platform. A first-floor bay generally needs a small scaffold for safe access.
Does a porch roof need a gutter?
Not always. Many small porches drip straight off the front edge, but a gutter helps over a doorway or path.
Can a canopy over a front door be re-covered?
Yes. Small canopies are re-covered in the same way as porches, usually in EPDM or GRP, subject to the minimum charge.
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