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 Stockton-on-Tees?
In Stockton-on-Tees, a mansard loft conversion typically costs £58,500–£85,500 for a typical rear mansard, including VAT at 20% (standard rate). Building costs in the North East run about 10% below the UK average, and the figures for Stockton-on-Tees are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear mansard | £58,500–£85,500 |
| Higher specification | £85,500–£107,000 |
Your quote will depend mainly on:
- Party wall surveyor fees
- Number of dormers and lead work
- Scaffolding on busy streets
- Front, rear or both
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 Stockton-on-Tees?
Whether you need planning permission depends on your house and its location in England. In England a mansard almost always needs planning permission because it changes the roof shape. Many councils publish design guidance for mansards on terraced streets, and some streets are more likely to be approved where neighbours already have one.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
From survey to sign-off, the job normally involves:
- Dormer windows
- Staircase and fire-safe escape route
- Building control sign-off
- Party wall notices to both neighbours
- Planning drawings and application
- Structural design and calculations
How long does it take?
The build itself usually takes 9 to 12 weeks on site, after planning approval. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in Stockton-on-Tees
Across the North East, colliery-era terraces and newer estates sit side by side, so the right project depends on the house type.
If your home is in Stockton-on-Tees or close by in Billingham, Thornaby-on-Tees and Middlesbrough, a free home visit is the first step.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 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 Stockton-on-Tees
How long does it take?
Around 9 to 12 weeks on site, plus 2 to 3 months for planning and party wall matters beforehand.
How much does a mansard loft conversion cost in Stockton-on-Tees?
In Stockton-on-Tees, a mansard loft conversion typically costs £58,500–£85,500 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.
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.
Who approves a mansard loft conversion in Stockton-on-Tees?
Planning matters in Stockton-on-Tees go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.