Loft Conversion Cost UK 2026 – Prices, Types and Complete Guide
Loft Conversion Cost depends on the conversion type, property structure, materials, insulation requirements, and finishing choices. LAMTANS Engineering helps homeowners across the UK understand typical prices, timelines, and planning considerations for Dormer, Velux, Hip-to-Gable, Mansard, and Room in Roof conversions from our Manchester base.
How Much Does a Loft Conversion Cost in the UK?
Loft conversion costs in the UK vary depending on the conversion type, property size, structural requirements, and level of finish. Whether you are considering a simple Velux conversion or a larger Dormer, Hip to Gable, or Mansard upgrade, understanding the typical costs, timelines, and value added can help you plan your project with confidence.
| Conversion Type | Typical Cost Range | Timeline | Adds to Property Value |
|---|---|---|---|
| Velux (roof windows) | £15,000 – £25,000 | 2–3 weeks | 5–10% |
| Dormer | £25,000 – £45,000 | 4–6 weeks | 10–15% |
| Hip to Gable | £35,000 – £55,000 | 6–8 weeks | 10–15% |
| Mansard | £45,000 – £70,000 | 8–10 weeks | 15–20% |
| Room in Roof (upgrade) | £10,000 – £20,000 | 3–5 weeks | 5–10% |
Estimated costs typically include structural alterations, insulation, electrical work, heating, plastering, flooring, and finishing. Additional features such as ensuite bathrooms (£5,000–£10,000+) may increase the overall project cost. Final price confirmed at your free survey.
02 — Cost Factors
What Affects Loft Conversion Cost in the UK?
The final loft conversion cost depends on several factors beyond the type of conversion you choose. Property structure, available space, roof design, access requirements, and finishing choices can all affect the overall budget.
Detailed Cost Breakdown by Loft Conversion Type
The cost of a loft conversion varies significantly depending on the design, structural changes required, and level of finish. Below is a breakdown of each conversion type — including typical prices, suitability, and what is usually included.
- Homes with existing headroom of around 2.2m or more
- Homeowners wanting a simple, cost-effective conversion
- Properties where major roof alterations are not required
- Roof window installation
- Floor reinforcement where required
- Insulation between and over rafters
- Staircase installation (if required)
- Plastering and decoration
- Electrical work and lighting
- Heating upgrades
- Ensuite bathroom
- Dormer structure
- Major roof shape changes
- Terraced and semi-detached homes
- Properties with limited existing headroom
- Creating bedrooms, offices, or larger living spaces
- Dormer structure with flat or pitched roof
- New windows
- Structural floor strengthening
- Staircase installation
- Full insulation upgrade
- Electrical and lighting
- Heating installation
- Plastering and finishing
- Building control approval
- Detached and semi-detached homes
- Properties with hipped roof designs
- Homeowners wanting more floor space than a standard Dormer
- Roof alteration to create gable wall
- Structural steelwork where required
- Additional floor space creation
- New windows
- Staircase installation
- Full insulation upgrade
- Electrical, lighting, and heating
- Plastering and decoration
- Homes where maximum additional space is required
- Large master bedrooms or self-contained living areas
- Properties where roof restructuring is suitable
- Complete roof structure alteration
- Mansard wall construction
- New roof covering
- Windows or French doors
- Structural steelwork
- Staircase installation
- Full insulation
- Electrical, heating, plastering, and finishing
- Existing loft rooms needing improvement
- Cold or poorly insulated spaces
- Properties with outdated electrics or finishes
- Insulation upgrades (including roof insulation)
- Electrical improvements
- Heating upgrades
- Plastering and decoration
- Flooring improvements
- Building regulation upgrades
- Final compliance checks
04 — Additional Costs
Additional Costs to Consider
The main loft conversion price usually covers the core construction work, but additional requirements can increase your overall budget. These costs depend on your property, design choices, structural requirements, and whether extra features are included.
| Item | Typical Cost |
|---|---|
| Ensuite bathroom | £5,000 – £10,000 |
| Roof windows (Velux) | £1,000 – £2,000 per window |
| Structural steelwork (if required) | £2,000 – £5,000 |
| Building control fees | £500 – £1,000 |
| Planning permission (if required) | £500 – £1,000 |
| Party wall agreement (if required) | £500 – £1,500 per neighbour |
| Scaffolding | £1,000 – £3,000 |
| Skip hire | £300 – £600 |
All additional costs are confirmed at your free survey. We provide a fixed, itemised quote — no hidden charges added after work begins.
Our Loft Conversion Process
Our clear six-step process guides you from initial survey through to a fully compliant, finished loft conversion — with a single point of contact and no surprises along the way.
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1
Free Consultation & Survey
We visit your property, assess your loft space — headroom, roof structure, access, and structural suitability — and discuss your requirements for conversion type, layout, and budget. No charge and no obligation.
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2
Structural & Design Planning
Our team produces a detailed structural specification and design plan for your loft conversion. This confirms exactly what work is required and forms the basis of your fixed-price quote — agreed in full before any work begins.
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3
Planning Permission & Building Control
Where planning permission is required — conservation areas, Mansard conversions, or properties exceeding permitted development limits — we guide you through the application process. For all conversions, we manage Building Control notifications and inspections throughout the project.
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4
Construction
Structural alterations, roof changes, floor strengthening, and staircase installation are completed by our experienced team. We work systematically to minimise disruption to your daily routine — you can remain in your home throughout the construction phase.
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5
Finishing & Fit-Out
Insulation, plastering, electrics, heating, flooring, and decoration are completed to the agreed specification. Windows, doors, and any bespoke features are fitted and finished — leaving your new loft space ready to use.
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6
Handover & Sign-Off
Your Building Control completion certificate is issued, confirming your loft conversion fully meets UK Building Regulations. We hand over all compliance documentation and warranties — giving you a clear, formal record of all work completed and the standards met.
How Much Value Does a Loft Conversion Add to Your Home?
A well-designed loft conversion can increase both the usable space and market appeal of your home. In many cases, adding an extra bedroom, office, or living area can increase property value by around 10–20%, depending on location, property type, and quality of the conversion.
| Property Type & Location | Current Value | Conversion Cost | Approx. Added Value |
|---|---|---|---|
| 2-bed terrace (Manchester city fringe) | £250,000 | £30,000 (Dormer) | £25,000 – £37,500 |
| 3-bed semi (Stockport) | £350,000 | £35,000 (Dormer) | £35,000 – £52,500 |
| 3-bed semi (Oldham) | £280,000 | £35,000 (Dormer) | £28,000 – £42,000 |
| 4-bed detached (South Manchester) | £550,000 | £50,000 (Mansard) | £55,000 – £82,500 |
Why Choose LAMTANS for Your Loft Conversion?
Choosing the right loft conversion company is essential for achieving a safe, energy-efficient, and regulation-compliant living space. LAMTANS Engineering combines retrofit expertise, project management, and quality standards to deliver professional loft conversions across the UK.
Frequently Asked Questions
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Is £30,000 a reasonable budget for a loft conversion in the UK? +
Yes — £30,000 is a realistic budget for a Dormer conversion on a typical 3-bedroom semi-detached property, depending on specification. A standard Dormer conversion costs £25,000–£45,000, with most 3-bed semi projects falling in the £30,000–£35,000 range. A Velux conversion costs less at £15,000–£25,000, while Hip to Gable and Mansard conversions start from £35,000. Contact us for an accurate quote specific to your property.
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How long does a loft conversion take? +
Timelines vary by conversion type: a Velux conversion typically takes 2–3 weeks; a Dormer takes 4–6 weeks; a Hip to Gable takes 6–8 weeks; and a Mansard conversion takes 8–10 weeks. A Room in Roof upgrade typically takes 3–5 weeks. These timelines do not include the time required for planning permission applications where needed, which can add several weeks depending on the local authority.
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Will a loft conversion add value to my home? +
Yes. A typical loft conversion adds 10–20% to your property value — and in most cases the added value compares very favourably to the cost of the conversion. The actual return depends on your location, demand for additional bedrooms, quality of the conversion, and whether the design meets buyer expectations. Properties in areas with strong demand for family homes — such as Greater Manchester — often see particularly strong returns on well-executed loft conversions.
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Can I convert my loft if I have a low roof? +
Yes. A Dormer or Mansard conversion can create additional headroom even where the existing loft height is limited. A Velux conversion generally requires existing headroom of around 2.2m or more to be practical. We assess your loft headroom during the free survey and recommend the most appropriate conversion type for your property and budget.
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Do I need to move out during the loft conversion? +
No — the work is contained in the loft. There will be some disruption (dust, noise, and tradespeople moving through the house), but you can live in the rest of your home throughout the conversion. We work systematically to minimise disruption and clean up at the end of each working day.
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What guarantee does LAMTANS provide on a loft conversion? +
Every loft conversion completed by LAMTANS includes full Building Control sign-off and a Building Control completion certificate, confirming the work meets UK Building Regulations. We provide all compliance documentation at handover — giving you a clear, formal record of all work completed and the standards met. This means your conversion is documented, certified, and provides reassurance to future buyers and mortgage lenders. View our accreditations →
Ready to Get an Accurate Loft Conversion Quote?
Get your free, no-obligation loft conversion survey today. We will assess your loft space, advise on the best conversion type for your property and budget, and provide a fixed price — at no cost to you. We aim to provide advice within 72 hours following your free survey.