Loft conversions remain one of the most cost-effective ways to add space and value to your home. We've compiled real project data from across the UK to give you the most accurate pricing guide available.
Loft conversions consistently rank as one of the best-value home improvements in the UK. According to Nationwide Building Society, a well-executed loft conversion can add up to 20% to a property's value — often significantly more than the cost of the work itself.
But costs vary enormously depending on the type of conversion, the size of your loft, your location, and the specification you choose. Here's our comprehensive 2025 pricing guide based on real project data from across the UK.
Types of Loft Conversion and Their Costs
There are four main types of loft conversion, each with different structural requirements and price points. The right choice for your property depends on your roof type, head height, and planning constraints.
- Velux / Rooflight conversion: £20,000–£35,000 — the simplest and most affordable option, no change to the roofline
- Dormer conversion: £35,000–£60,000 — extends the roof to create a box-shaped structure, maximising usable floor space
- Hip-to-gable conversion: £40,000–£65,000 — extends a hipped roof to create a vertical gable end, common on semi-detached houses
- Mansard conversion: £50,000–£80,000 — the most extensive type, changes the entire roof structure, maximum space but requires planning permission
These are indicative ranges for a standard two-bedroom house in the Midlands. London and South East prices are typically 20–35% higher. Always get a professional estimate for your specific property.
What's Included in the Cost?
A professional loft conversion quote should include all of the following elements. Be wary of quotes that seem unusually low — they may be excluding key items that will be added as extras later.
- Structural steelwork and timber frame
- Roof alterations and new roofing materials
- Insulation (floor, walls, and roof)
- Staircase design and installation
- Dormer windows or Velux rooflights
- Electrical first and second fix
- Plumbing if adding an en-suite
- Plastering and internal finishes
- Flooring (typically allowance for carpet or engineered wood)
- Building regulations compliance and sign-off
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Material prices are moving fast. Our estimates use live 2026 rates — so your budget reflects what things actually cost right now, not 12 months ago.
Additional Costs to Budget For
Beyond the main construction costs, there are several additional expenses that many homeowners overlook when budgeting for a loft conversion.
- Architect or designer fees: £1,500–£4,000
- Structural engineer: £500–£1,500
- Building regulations application: £200–£500
- Party wall agreement (if applicable): £700–£2,000 per neighbour
- Planning permission (if required): £206 application fee plus consultant fees
- Furniture and decoration: £3,000–£10,000+
- VAT at 20% on all labour and materials
Always add a 10–15% contingency to your budget for unforeseen works. Even on well-planned projects, surprises happen — especially in older properties.
How to Get the Best Value
Getting the best value from your loft conversion isn't just about finding the cheapest contractor. It's about making smart decisions at every stage of the project.
Start with a professional estimate before approaching contractors. This gives you an independent benchmark to evaluate quotes against and puts you in a much stronger negotiating position. Contractors are far less likely to inflate prices when they know you have a professional cost plan.
Page Building Consultants can produce a detailed loft conversion estimate within 24 hours of receiving your drawings. Call us on 0800 688 9321 or submit your plans online to get started.