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 Portadown?
In Portadown, a mansard loft conversion typically costs £56,000–£81,500 for a typical rear mansard, including VAT at 20% (standard rate). That range is adjusted for Northern Ireland, where domestic building work typically costs around 14% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £56,000–£81,500 |
| Higher specification | £81,500–£102,000 |
The main things that change the cost:
- Front, rear or both
- Bathrooms and finishes
- Scaffolding on busy streets
- Roof covering: natural slate costs more
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a mansard loft conversion in Portadown?
Whether you need planning permission depends on your house and its location in Northern Ireland. In Northern Ireland a mansard needs planning permission from the council.
In Northern Ireland building control approval comes from the council, usually through a full plans application or a building notice, with inspections during the work and a completion certificate at the end.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most mansard loft conversions:
- Staircase and fire-safe escape route
- Planning drawings and application
- Dormer windows
- Building control sign-off
- Written agreement with neighbours on shared walls
- New roof structure, slate or tile covering and lead work
How long does it take?
Build time is typically 9 to 12 weeks on site, after planning approval. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Portadown
Northern Ireland has many detached and semi-detached homes on generous plots, which suits single-storey rear extensions and garage conversions.
Portadown sits in County Armagh, about 10 miles north-east of Armagh. We cover the whole of Portadown, including postcodes BT62 and BT63.
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 pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about mansard loft conversions in Portadown
How long does a mansard loft conversion take in Portadown?
Typically 9 to 12 weeks on site, after planning approval. Design and approvals beforehand usually take 3 to 4 months.
What roof covering is used?
Natural slate is traditional; some councils accept other materials. We follow local guidance.
How much does a mansard loft conversion cost in Portadown?
In Portadown, a mansard loft conversion typically costs £56,000–£81,500 for a typical rear mansard, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
Can I stay at home?
Usually. The new roof is built under a temporary cover so the house stays dry.
Do I need planning permission for a mansard loft conversion in Portadown?
In Northern Ireland a mansard needs planning permission from the council.
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.