How Much Does A Loft Conversion Cost In 2025?

As a leading London-based construction firm, PRG Extensions specializes in transforming underutilized loft spaces into functional and stunning living areas. If you’re considering a loft conversion, understanding the costs involved is essential for effective budgeting and planning. Let’s break down the key factors that influence these costs and provide insights into common loft conversion types.

There are various types of loft conversions, each tailored to different needs and property types. Here’s an overview of the most common options:

• Velux Conversion: Adds Velux windows to the existing roof without altering the structure, making it the most cost-effective choice.
• Dormer Conversion: Extends the roof outward to create more headroom and usable space. This can be a single dormer, multiple dormers, or a full-width structure.
• Mansard Conversion: Involves significant roof restructuring to create a flat roof and near-vertical walls, offering maximum space.
• Hip-to-Gable Conversion: Converts a sloped roof into a vertical gable, increasing internal space.
• Gable-to-Gable Conversion: Extends the gable end across the property’s width for enhanced functionality.
• Roof Lift Conversion: Raises the entire roof to add headroom, often requiring substantial structural work.
• Modular Conversion: Prefabricated sections are constructed off-site and assembled on the property for quicker installation.
• Standard Loft Conversion: Focuses on internal adjustments without major structural changes, ideal for straightforward projects.

At PRG Extensions, we specialize in standard loft conversions, dormer loft conversions, and Mansard loft conversions, tailoring each project to your property’s unique characteristics.

Several variables can impact the overall cost of a loft conversion:

1. Size of the Space: The larger the loft area, the higher the costs due to additional materials and labor.
2. Type of Conversion: Structural changes, such as roof lifts or Mansard conversions, involve higher expenses than Velux or standard conversions.
3. Specifications: Finishes range from basic to high-end, with options tailored to your budget and style preferences.
4. Additional Features: Adding en-suite bathrooms, storage solutions, or balconies will increase costs.
5. Location: London-based projects typically cost more due to higher labor rates and stricter regulations.

For illustrative purposes, consider a 30-square-metre loft conversion with the following features:

• Master bedroom
• En-suite bathroom
• Eaves storage
• Landing with stairs

PRG Extensions offers three finish levels:

• Basic Finish: Economical options (e.g., Leyland, Wickes).
• Standard Finish: Mid-range selections (e.g., Dulux, Hamilton).
• Premium Finish: High-end finishes (e.g., Farrow & Ball, Siemens).

For this comparison, we focus on standard finishes and mid-range contractors.

Here’s a breakdown of typical costs based on the type of loft conversion and a 35-square-metre area:

Note: Costs exclude VAT and additional expenses like planning permissions, structural surveys, or unforeseen repairs.

For dynamic estimate use our on-line calculator

1. Do I need to move out during the conversion?
In most cases, you won’t need to move out. However, expect noise and dust. For major structural changes like roof lifts, temporary relocation may be recommended.

2. What are the headroom requirements?
Building regulations require a minimum headroom of 2.2 metres (7 feet 2 inches). If your loft doesn’t meet this requirement, adjustments can be made.

3. Can I convert the loft in a terraced or semi-detached house?
Yes, but shared walls and planning permissions must be considered. Properties in conservation areas may face additional restrictions.

4. What fire safety measures are required?
Loft conversions must comply with UK fire safety regulations, including fire-resistant doors, enclosed escape routes, and interlinked smoke alarms on each floor.

Why Choose PRG Extensions?

With years of experience and a reputation for excellence in London, PRG Extensions is your trusted partner for loft conversions. From initial design to project completion, we ensure every detail meets your expectations. Contact us today to transform your loft into a functional, stylish space.