---
title: "How Much Does a Loft Conversion Cost in London in 2026?"
description: "Find a full breakdown of loft conversion prices in London in 2026 in this guide. Learn what impacts the cost of a loft conversion in London, labour rates & more."
url: "https://www.myjobquote.co.uk/costs/loft-conversion-in-london-cost"
last_updated: "2026-10-12"
---

# Loft Conversion Cost in London

 At a Glance

- The average loft conversion in London costs around £46,000.
- Most loft conversions in London take 4 to 10 weeks to complete.
- Velux conversions are the cheapest option, from around £23,000.
- Mansard conversions are the most expensive, averaging around £80,000.

 **In this guide, you'll find:**

- Average loft conversion costs in London by type and size.
- Extra costs to budget for, including scaffolding, staircases, and party wall awards.
- How long a loft conversion typically takes in London.
- How MyJobQuote can help you get quotes from local contractors.

  [Get free estimates](https://www.myjobquote.co.uk/loft-conversion) **Are you a trade? [Get more work today!](https://www.myjobquote.co.uk/tradespeople-signup)**

A loft conversion is one of the best ways to add extra space to a London home, especially if moving away from a good school catchment or transport links isn't an option. Whether you need a spare bedroom, a home office, or space for a growing family, converting an unused loft can make a real difference without the upheaval of a house move.

This guide covers the average [loft conversion cost](https://www.myjobquote.co.uk/costs/loft-conversion) in London, broken down by type and size, along with the extra costs and factors that are specific to converting a loft in the capital. A well-finished loft conversion can also add up to 24% to your property's value.

For a more precise estimate based on your own property, try our [loft conversion cost calculator](https://www.myjobquote.co.uk/cost-calculators/loft-conversion-cost-calculator) before getting quotes.

### Average cost of a loft conversion in London:

#### Depending on the job's complexity, it usually takes 4 – 10 weeks.

##### £46,000

## What Is the Cost of a Loft Conversion in London?

*How much does the average loft conversion in London cost?*

The cost of a loft conversion in London depends on the type you choose, the size of the space, and the amount of structural work involved. A 30m² dormer conversion, a common choice in the capital, typically costs between **£40,500** and **£57,500**. However, costs start at around £23,000 for a small Velux loft, rising to around £105,000 for a larger mansard conversion.

Loft conversion costs in London typically range from **£1,800 to £2,700** per m², which is around 15% to 25% higher than the UK average, reflecting higher labour and material costs in the capital.

What are you planning to use your loft conversion for?

Bedroom/Guest room

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Home office or study

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Bathroom

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Additional living space

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### Loft Conversion Prices in London

Below are the average costs for the most common loft conversion types in London, based on a 30m² and 50m² project.

| Type of Conversion | Average Cost (30m²) | Average Cost (50m²) |
|---|---|---|
| Velux Loft Conversion | £23,000–£34,500 | £29,000–£46,000 |
| Dormer Loft Conversion | £40,500–£57,500 | £52,000–£80,500 |
| Hip-to-Gable Loft Conversion | £52,000–£69,000 | £63,500–£80,500 |
| Mansard Loft Conversion | £70,000–£90,000 | £85,000–£105,000 |
| L-Shaped Dormer Loft Conversion | £57,500–£69,000 | £63,500–£80,500 |
| Shell Loft Conversion | £23,000–£46,000 | £34,500–£63,500 |

## Cost of a Loft Conversion in London by Type

### Velux Loft Conversion

A [Velux conversion](https://www.myjobquote.co.uk/costs/velux-loft-conversion) adds rooflights within your existing roofline, so the shape of the roof doesn't change, although new floor joists are normally still needed. It's the fastest and most affordable option for a London loft, and it's usually covered by permitted development. Cost per m² is typically between **£750** and **£1,150** in London.

### Dormer Loft Conversion

A [dormer conversion](https://www.myjobquote.co.uk/costs/dormer-loft-conversion) builds a box-shaped structure into the pitched roof, creating a flat ceiling and much more usable floor space. It's a popular choice for London's Victorian and Edwardian terraces. Cost per m² is typically between **£1,350** and **£1,950** in London.

### Hip-to-Gable Loft Conversion

This conversion replaces a sloping roof end with a vertical gable wall, creating a significant amount of extra space. It only works on homes with a hipped roof, which are more common in London's outer boroughs than in inner-city terraces. The average [cost of a hip-to-gable loft conversion](https://www.myjobquote.co.uk/costs/hip-to-gable-loft-conversion-cost) per m² is typically between **£1,750** and **£2,300** in London.

### Mansard Loft Conversion

A [mansard loft conversion](https://www.myjobquote.co.uk/costs/mansard-loft-conversion) changes the whole shape of the roof and adds a large amount of extra space. It's a popular option for London's flat-fronted terraced houses. Cost per m² is typically between **£2,300** and **£3,000** in London, but can be more.

### L-Shaped Dormer Loft Conversion

An L-shaped dormer combines a rear and side dormer to create a larger loft space that's well-suited to Victorian and Edwardian terraces. Cost per m² is typically between **£1,900** and **£2,300** in London.

### Shell Loft Conversion

A shell loft conversion involves creating the basic structure of the loft without the final finishes. It's often chosen when the homeowner wants to have more control over the finishing touches or when they plan to do the work themselves. Cost per m² is typically between **£750** and **£1,550** in London.

## What Type of Loft Conversion Suits Your London Property?

London's housing stock includes large numbers of Victorian and Edwardian terraces, along with many interwar and post-war semi-detached houses in the outer boroughs. The right loft conversion for your home often depends on which of these you have.

- **Inner London Terraces —** Dormer and mansard loft conversions are often the most practical choice for Victorian and Edwardian terraces, as they maximise headroom and living space while working well with the existing roof structure.
- **Outer London Semis and Detached Homes —** Boroughs such as Bromley, Sutton, and Kingston have more semi-detached and detached properties with hipped roofs, making hip-to-gable conversions a practical option.
- **Conservation Areas —** London has a high concentration of conservation areas and listed buildings, particularly in boroughs such as Westminster, Kensington and Chelsea, Islington, and Camden. [Camden alone has around 40 conservation areas](https://www.camden.gov.uk/conservation-areas), covering roughly half the borough. Loft conversions in these areas require planning permission if the roof area will be enlarged (e.g. with a dormer or mansard conversion), with councils often expecting new roof materials to match the character of the existing building.

We're planning a dormer loft conversion on a 1930s semi. How long should we realistically budget for from start to finish? We'd need to stay in the house throughout.

"Where a planning is ready signed and money flow without any delays the dormer loft conversion should take no longer than 3 months from start to finish."

 [Johanson Ltd (Loft Conversion Specialist in London)](https://www.myjobquote.co.uk/t/johanson-ltd)

If you're weighing up costs across different parts of the country, our [loft conversion cost guide for Manchester](https://www.myjobquote.co.uk/costs/loft-conversion-in-manchester-cost) shows how prices in the north currently compare with London.

## Additional Loft Conversion Costs in London

Budget for these additional costs on top of the main build. Some, like planning fees, are set nationally, and don't change by region. Others, like scaffolding and skip hire, tend to cost more in London due to limited parking and higher demand for tradespeople.

| Job Description | Average Price |
|---|---|
| [Architectural drawings](https://www.myjobquote.co.uk/costs/architect-prices) | £440–£1,650 |
| [Structural engineer calculations](https://www.myjobquote.co.uk/costs/structural-engineer) | £650–£2,000 |
| Planning permission fees | £548 |
| Building regulations approval | £850–£1,350 |
| Party wall award (single surveyor) | £800–£1,000 |
| Party wall award (disputed, per surveyor) | £1,500+ |
| [Scaffolding hire](https://www.myjobquote.co.uk/costs/cost-of-hiring-scaffolding) | £1,800–£4,000 |
| [Skip hire](https://www.myjobquote.co.uk/costs/skip-hire) | £230–£635 |
| [Standard staircase installation](https://www.myjobquote.co.uk/costs/installing-a-new-staircase) | £1,650–£2,750 |
| Bespoke staircase installation | £5,500–£11,000 |

Party wall agreements come up more often in London than in most of the UK, simply because so many homes are terraced or semi-detached and share a wall with a neighbour. If a neighbour disputes the work, each side may need to appoint their own surveyor, which is where costs can rise.

You will need a skip licence if you will be placing a skip on the road, although the skip hire company will usually apply for this. If you'll have scaffolding on the road or pavement, you'll also need a licence from the council. If either the skip or scaffolding will take up a parking space, a parking bay suspension is also needed. Each of these adds a small extra cost and is worth arranging in advance.

## How Long Does a Loft Conversion Take in London?

Most loft conversions in London take 4 to 10 weeks, though this can vary depending on the type of conversion, access to the property, and whether a party wall agreement or planning permission is needed. Conservation areas are more common in London than in most UK cities, which can add 8 weeks (the usual time for a planning decision) if planning permission is required.

| Loft Type | Average Timescale |
|---|---|
| Velux | 4 to 6 Weeks |
| Dormer | 6 to 8 Weeks |
| Hip-to-Gable | 6 to 8 Weeks |
| Mansard | 8 to 10 Weeks |

## Checklist: Hiring a Loft Conversion Builder in London

Hiring an experienced contractor helps ensure the work meets building regulations and is finished to a high standard. When comparing quotes from London tradespeople, check the following:

- Experience with similar loft conversions in London.
- Positive reviews from previous customers.
- Whether structural calculations are included in the quote.
- Knowledge of building regulations and, where relevant, conservation area rules.
- Whether they'll manage other trades and the party wall process.
- Timescales and payment terms.
- Relevant insurance cover.
- Guarantees for workmanship.