Velux, Dormer, or Hip-to-Gable? Choosing the Right Loft Conversion for Your Home

When planning a loft conversion, one of the biggest decisions you’ll make is how the loft will be formed and lit. The choice between a Velux (rooflight) conversion, a dormer, or a hip-to-gable conversion has a major impact on cost, space, natural light, planning requirements, and how the finished room feels.

There’s no single “best” option — the right solution depends on your roof type, budget, property style, and how you want to use the space. Understanding the differences early on helps you make confident, cost-effective decisions.

Velux Loft Conversions (Rooflight Conversions)

What Is a Velux Loft Conversion?

A Velux loft conversion involves installing roof windows into the existing roof slope without altering the roof structure. The external roofline remains unchanged.

When Is a Velux Conversion Suitable?

Velux conversions work best when:

• The loft already has good head height

• The roof pitch is steep enough

• You want a cost-effective solution

• Minimal external changes are preferred

They are common in terraced and semi-detached houses with traditional pitched roofs.

Cost and Space

Velux conversions are usually the most cost-effective option because:

• No major structural roof changes are required

• Construction time is shorter

• Less scaffolding is needed

However, they do not significantly increase floor space. The usable area is limited by the existing roof shape.

Planning Permission

In most cases, Velux conversions fall under permitted development, meaning planning permission is not required (subject to conditions).

Light and Roof Orientation

Velux windows provide excellent natural light:

• South-facing roofs benefit from strong daylight and warmth

• North-facing roofs offer softer, more consistent light, ideal for bedrooms or studies

Proper glazing and blinds are important to control heat on south-facing elevations.

Dormer Loft Conversions

What Is a Dormer Conversion?

A dormer involves extending part of the roof outward to create additional headroom and floor space. Dormers can be added to the rear, side, or (less commonly) the front of a property.

When Is a Dormer Suitable?

Dormers are ideal when:

• Existing head height is limited

• You want to maximise usable space

• You need room for a bathroom or larger bedroom

• You want more flexibility in layout

They are one of the most popular loft conversion options in the UK.

Cost and Space

Dormers cost more than Velux conversions but:

• Create significantly more usable floor area

• Allow for full-height walls

• Make it easier to add bathrooms, wardrobes, and storage

In terms of space gained vs cost, dormers often offer the best overall value.

Planning Permission

Many rear dormers fall under permitted development, provided they meet size and design limits. Front-facing dormers usually require planning permission.

Light and Design

Dormers allow for:

• Standard vertical windows

• Better ventilation

• A room that feels more like a traditional bedroom

They also make furniture placement much easier.

Hip-to-Gable Loft Conversions

What Is a Hip-to-Gable Conversion?

A hip-to-gable conversion involves extending the sloping side of a hipped roof (common on semi-detached and detached houses) to form a vertical gable wall.

When Is a Hip-to-Gable Suitable?

This option is ideal when:

• The property has a hipped roof

• The existing loft space is restricted

• Maximum space is a priority

• A master bedroom or large suite is planned

Hip-to-gable conversions are often combined with a rear dormer for maximum impact.

Cost and Space

Hip-to-gable conversions:

• Are more expensive than Velux or simple dormers

• Provide substantial increases in floor area

• Dramatically improve layout flexibility

They are often the best choice when homeowners want to create a large, high-value living space.

Planning Permission

Hip-to-gable conversions usually fall under permitted development, but this depends on property type, location, and size. Corner plots or homes in conservation areas often require planning permission.

Which Option Gives the Most Space?

In terms of space gained:

1. Velux – Minimal increase, best for existing head height

2. Dormer – Significant usable space

3. Hip-to-Gable (often with dormer) – Maximum space and flexibility

If space is the main priority, hip-to-gable or dormer solutions are usually the best investment.

Which Option Is Most Cost-Effective?

Cost-effectiveness depends on goals:

• Velux conversions offer the lowest entry cost

• Dormers provide the best balance of cost and space

• Hip-to-gable delivers maximum value but at a higher initial cost

The “best” option is the one that meets your needs without overbuilding.

Roof Orientation: North vs South Facing

Roof direction plays an important role in comfort and usability.

• South-facing roofs receive more sunlight and warmth — ideal for living spaces but may require solar-control glazing.

• North-facing roofs provide cooler, even light — excellent for bedrooms and home offices.

A well-designed loft considers window placement, insulation, and ventilation to ensure year-round comfort.

What’s Best for Your Home?

There is no one-size-fits-all answer. The best loft conversion option depends on:

• Roof type and structure

• Available head height

• Budget

• Intended room use

• Planning constraints

Professional advice at the design stage ensures the right balance between cost, space, light, and long-term value.

Conclusion: Making the Right Choice Early

Choosing between Velux, dormer, and hip-to-gable loft conversions is one of the most important decisions in the project. Each option offers different benefits in terms of cost, space, light, and planning requirements.

With careful planning and expert guidance, your loft conversion can be tailored perfectly to your home — creating a bright, comfortable, and valuable new living space that transforms both your lifestyle and your property.

Comparison Table for Loft Conversion Types

Feature / Consideration	Velux (Rooflight) Conversion	Dormer Conversion	Hip-to-Gable Conversion
Definition	Roof windows added to slope	Roof extended outward to create vertical walls	Hipped roof side extended to form a gable wall, often with dormer
Usable Space	Limited	Moderate	Maximum
Cost	Lowest	Medium	Highest
Construction Complexity	Low	Medium	High
Planning Permission	Usually not required	Rear often PD, front usually required	Often PD, check location/plot
Roof Type Suitability	Pitched roofs	Most pitched roofs	Hipped roofs only
Light	Excellent for south-facing	Good natural light	Excellent when combined with dormer
Best For	Single bedroom or study	Bedrooms, bathrooms, family spaces	Large bedrooms, master suites, max space
Time to Complete	Shortest	Medium	Longest
Aesthetic Impact	Minimal external change	Moderate change	Major external alteration

Buyer’s Guide Version

Choosing the Right Loft Conversion: A Quick Guide

When planning a loft conversion, consider these key factors:

1. Budget

   • Velux conversions are cost-effective with minimal structural changes.

   • Dormers give extra space at moderate cost.

   • Hip-to-gable conversions offer maximum space but are more expensive.

2. Space Requirements

   • Velux: limited floor space, ideal for small bedrooms or offices.

   • Dormer: creates full-height rooms, good for bathrooms and bedrooms.

   • Hip-to-gable: maximises space, perfect for master bedrooms or multiple rooms.

3. Planning Permission

   • Velux conversions: usually permitted development.

   • Dormer: rear often PD; front usually needs planning permission.

   • Hip-to-gable: often PD, but check with local authority.

4. Roof Orientation

   • South-facing roofs: brighter, warmer, consider blinds or heat-reducing glass.

   • North-facing roofs: softer, consistent light, ideal for bedrooms or offices.

5. Intended Use

   • Single bedroom/study: Velux

   • Family bedroom/bathroom: Dormer

   • Master suite or multi-room conversion: Hip-to-gable

Professional advice early ensures the right balance of cost, space, light, and long-term value.

3. FAQs Specific to Loft Conversion Types

1. What is the difference between a Velux and a dormer loft conversion?

Velux conversions use roof windows in the existing slope, keeping the roofline unchanged. Dormer conversions extend part of the roof outward, creating more headroom and usable space.

2. Can I do a loft conversion on a hipped roof?

Yes — a hipped roof is ideal for a hip-to-gable conversion, which extends the sloping side into a vertical gable, often combined with a dormer to maximise space.

3. How much extra space does a dormer give compared to a Velux?

Dormers can increase usable floor space by 50–70% over a Velux conversion, depending on roof size, head height, and shape.

4. Which loft conversion is most cost-effective?

Velux conversions are the most budget-friendly, followed by dormers. Hip-to-gable offers the most space but is the most expensive option.

5. Do I need planning permission for a loft conversion?

• Velux: usually no planning required

• Dormer: rear dormers often PD; front dormers usually require permission

• Hip-to-gable: often PD, but check with your local authority

6. Can I add a bathroom to any loft conversion?

Dormer and hip-to-gable conversions are best for bathrooms due to floor space and layout. Velux conversions are usually limited to bedrooms or offices.

7. Will the type of roof affect my options?

Yes. Velux and dormer conversions work on most pitched roofs. Hip-to-gable only works with hipped roofs.

8. How long does each type take to complete?

• Velux: ~3–6 weeks

• Dormer: ~6–10 weeks

• Hip-to-gable (with dormer): ~10–14 weeks

9. Which conversion provides the most natural light?

Velux conversions allow direct sunlight and are ideal for south-facing roofs. Dormers and hip-to-gable combined with windows provide excellent light while increasing usable space.

10. Are there any restrictions for corner plots or conservation areas?

Yes. For hip-to-gable and front dormers, planning permission may be required on corner plots or in conservation areas.

11. Can I combine types for more flexibility?

Absolutely. A hip-to-gable conversion is often combined with a rear dormer to maximise space, light, and layout flexibility.

12. How do I choose the best option for my home?

Consider your budget, roof type, space requirements, planning rules, and intended use. Professional advice ensures the most cost-effective and practical solution for your needs.