Understanding the cost of a loft conversion is one of the first steps when planning your project. Prices can vary widely depending on the type of conversion, property structure, and level of finish, but having a clear breakdown helps you budget effectively.
This guide provides a realistic overview of loft conversion costs in the UK for 2026.
Average Loft Conversion Costs in the UK
Here is a general cost guide:
- Velux Conversion: £25,000 – £35,000
- Dormer Conversion: £45,000 – £65,000
- Hip-to-Gable: £55,000 – £75,000
- Mansard Conversion: £65,000 – £90,000+
These figures can vary based on location, with areas like St Albans typically slightly higher due to demand.
Cost by Loft Conversion Type
Velux conversions are the most affordable because they require minimal structural changes.
Dormer conversions are the most common and provide the best balance between cost and usable space.
Hip-to-gable and mansard conversions involve more structural work, which increases costs but also maximises space.
Cost per Square Metre
On average, loft conversions cost between £1,200 and £2,000 per square metre.
Higher-end finishes, bespoke designs, and premium materials will increase the overall cost.
Hidden Costs to Consider
Many homeowners underestimate additional expenses such as:
- Structural engineering calculations
- Architectural drawings
- Staircase installation
- Plumbing and electrical work
- Insulation upgrades
Factoring these in early prevents budget surprises later.
Budget vs Premium Builds
A basic loft conversion focuses on functionality, using standard materials and finishes.
A premium conversion may include:
- En-suite bathroom
- Custom joinery
- High-end lighting
- Smart home features
The choice depends on your budget and long-term goals.
Costs in St Albans vs Other Areas
In higher-value locations like St Albans, labour and material costs can be slightly higher.
However, the return on investment is also stronger, making it a worthwhile upgrade.
Final Thoughts
A loft conversion is a significant investment, but when planned correctly, it offers excellent value for money. Understanding the cost structure allows you to make informed decisions and maximise the return on your project.