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Trusted Loft Conversions
Velux skylights installed in a loft conversion
Most Affordable Loft Conversion

Velux Loft Conversion Specialists

A Velux loft conversion costs between £15,000 and £25,000 in the UK — the most affordable option as it requires no structural changes to the roofline.

A Velux loft conversion works within your existing roof structure, adding roof windows for natural light and airflow. It is the fastest, most cost-effective route to a new bedroom, and it usually falls within Permitted Development.

From £15,000
Timescale: 4–6 weeks

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What is a Velux Loft Conversion?

A Velux loft conversion, sometimes called a rooflight conversion, uses your existing roof structure without changing its shape or adding a dormer. We fit Velux roof windows flush within the roof slope. They bring in daylight and fresh air while keeping the outside of your home looking exactly as it does now.

Because we keep most of the existing roof, this is the quickest and cheapest type of loft conversion. There is minimal scaffolding and far less structural work, so the build typically runs four to six weeks. On top of that, it is the conversion least likely to need planning permission.

A Velux conversion works best where the roof already has a steep pitch of 35 degrees or more, which gives good natural headroom. If your ridge height is marginal, we tell you straight whether a Velux can still deliver a comfortable, habitable room or whether a dormer would suit you better.

Key Benefits of a Velux Conversion

Most Affordable

Starting from £15,000, a Velux conversion is the most budget-friendly way to add a habitable loft room.

Minimal Disruption

No major structural alterations, less scaffolding, and a faster build means less impact on your day-to-day life.

Fast Completion

Most Velux conversions are complete in 4–6 weeks — the quickest of all loft conversion types.

Usually No Planning

Rooflights flush with the slope almost always fall within Permitted Development — no planning fees or delays.

Is a Velux Conversion Right for My Home?

A Velux conversion suits properties where the existing roof already gives reasonable headroom and you are happy to keep the roof line as it is. Run through the checklist below to see whether your home fits.

  • Roof pitch of 35° or steeper — provides good natural headroom without structural alteration
  • Ridge height of at least 2.5 m above existing ceiling joists (we measure on survey)
  • Good existing roof condition — rafters and roof covering in sound condition
  • No desire to significantly alter the external roof line
  • Budget-conscious project where maximum affordability is the priority
  • Urgency — Velux conversions can be designed, approved, and built in the shortest time

Where headroom is borderline, we will compare a Velux against a dormer and give you an honest recommendation based on your specific property.

What's Included in Every Velux Conversion

Free site survey and headroom assessment
Architectural drawings for building regulations
Permitted Development check and confirmation
Building regulations submission and approval
Structural engineer sign-off on floor joists
All scaffold, materials, and plant
Supply and installation of Velux roof windows
Insulation between and below rafters (warm roof specification)
New structural floor and floor boarding
Stud walls, plasterboard, and first-fix electrics
New staircase and fire-rated landing door
Final clean, snagging, and building regs sign-off

Typical Cost and Timescale

Cost Guide

From £15,000

This covers the full project, including all planning, structural, and build work. As a result, it is the most affordable loft conversion type available.

Build Programme

4–6 weeks

This is the fastest of all conversion types. Minimal structural work means a shorter programme and far less disruption to your household.

All quotes are fixed-price with no hidden extras.

Frequently Asked Questions

What size Velux windows can I install in a loft conversion?
Velux make roof windows from compact 55×78 cm units up to large 114×118 cm panoramic panes. The right size for your loft depends on rafter spacing and roof pitch. As a rule, we fit the largest windows your structure allows, because bigger glazing means more daylight and better airflow. Our free survey then specifies the best sizes and positions for your roof.
Does a Velux loft conversion need planning permission?
In most cases, no. Velux (rooflight) conversions almost always fall within Permitted Development rights, because they do not change the roof shape or add any volume. However, the windows must sit flush with the roof plane. They also must not project forward of the slope on the principal elevation, which is the side facing the road. We confirm Permitted Development eligibility on every survey. If you live in a conservation area, our team handles the application for you.
Is a Velux conversion suitable for use as a bedroom?
Yes, provided it meets building regulations. A habitable Velux loft room needs at least 2.2 m of headroom over part of the floor area. It also needs fire-safe staircase access, proper insulation, emergency escape windows, and compliant electrics. We design every Velux conversion to these standards from day one. As a result, your new room is legally habitable and comfortable all year round.
What is the minimum headroom needed for a Velux loft conversion?
Building regulations require at least 2.2 m of clear headroom over part of the habitable floor area. In practice, your existing ridge height should be at least 2.5 m above the ceiling joists. That leaves room for the new insulation and flooring. We check this on our free survey. If your ridge height is marginal, we tell you honestly whether a Velux or a dormer conversion suits you better.
Can Velux windows be installed in any type of roof?
Velux roof windows suit most pitched roofs between 15° and 90°. They work best on steeper pitches of 35° or more, where they bring in the most natural light. Flat or near-flat roofs need specialist flat-roof units instead. We assess your roof during the free survey and recommend the best glazing for your pitch and rafter layout.

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