What is a mansard loft conversion?
A mansard loft conversion rebuilds the roof with a nearly vertical slope (about 72 degrees) and a flat top, effectively adding a new storey. Small dormer windows sit within the steep slope. Mansards are common on period terraces in towns and cities.
How much does a mansard loft conversion cost in Holyhead?
In Holyhead, a mansard loft conversion typically costs £60,000–£87,500 for a typical rear mansard, including VAT at 20% (standard rate). The guide for Holyhead reflects typical costs in Wales, roughly 8% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £60,000–£87,500 |
| Higher specification | £87,500–£109,500 |
Your quote will depend mainly on:
- Scaffolding on busy streets
- Front, rear or both
- Roof covering: natural slate costs more
- Number of dormers and lead work
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a mansard loft conversion in Holyhead?
Before anything is built in Holyhead, we confirm which approvals apply in Wales. In Wales a mansard roof needs planning permission and is judged against local design guidance.
The Party Wall etc. Act 1996 applies in Wales, so notices must be served before work on a shared wall, on the boundary, or excavation close to a neighbour’s foundations.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
The work we manage on a mansard loft conversion:
- Structural design and calculations
- Dormer windows
- Building control sign-off
- Staircase and fire-safe escape route
- Planning drawings and application
- Insulation, electrics, plumbing and plastering
How long does it take?
Allow 9 to 12 weeks on site, after planning approval. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Holyhead
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
Holyhead sits in Gwynedd, about 22 miles west of Bangor. We cover the whole of Holyhead, including postcodes LL65.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about mansard loft conversions in Holyhead
Who approves a mansard loft conversion in Holyhead?
Planning matters in Holyhead go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a mansard loft conversion cost in Holyhead?
In Holyhead, a mansard loft conversion typically costs £60,000–£87,500 for a typical rear mansard, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Why choose a mansard over a dormer?
A mansard gives more usable floor space and a neater appearance from the street, but costs more and needs planning permission.
Do I need planning permission for a mansard loft conversion in Holyhead?
In Wales a mansard roof needs planning permission and is judged against local design guidance.
Do I need party wall agreements?
Yes, mansards on terraced houses almost always involve both party walls.
How long does it take?
Around 9 to 12 weeks on site, plus 2 to 3 months for planning and party wall matters beforehand.