Thinking of adding more space to your home without sacrificing your garden? Loft conversions are a great option! They create usable rooms, improve energy efficiency through insulation, and can even boost your property value – especially Victorian loft conversions which create beautiful and functional spaces from unused roof areas.

This guide compares two popular and affordable loft conversion options: Dormer and Velux.

Dormer Loft Conversions

Dormer

These are popular and functional additions, commonly seen on period properties in London.

  • What they are: Box-shaped extensions built upwards from the roof at a 90-degree angle. You can choose from various styles like half dormers, full dormers, or even double dormers for an L-shaped conversion.
  • Key features: Can be positioned on the rear or side of the house, with flat, pitched, or hipped roofs. Gable-fronted dormers add a more intricate touch. Dormer windows provide excellent light and ventilation.
  • Benefits: Increased floor space and headroom, uniform functionality due to consistent head height, design versatility with various roof and dormer styles. In Victorian properties, dormers can extend the roof on the rear.
  • Things to consider:
    • Suitability: Terraced, semi-detached, and detached houses with pitched roofs.
    • Planning permission: While some dormers fall under permitted development rights, others might require planning permission. This is especially true for loft conversions on designated land or where dormers are very prominent. Even rear dormers not visible from the street might need approval.
    • Permitted development limitations: Additional roof space cannot exceed 40 cubic meters for terraced houses and 50 cubic meters for detached/semi-detached properties (including any previous loft conversions). Dormers cannot be higher than the existing roof, and materials should complement the house’s style. Balconies, verandas, and raised platforms are not permitted under permitted development rights.
    • Cost: £1,250 – £1,450 per square metre.

Velux Loft Conversions

The simplest and most cost-effective option for loft conversions.

  • What they are: Use Velux windows installed directly into the roof to create a habitable loft space. Unlike dormers, they don’t require major structural changes to the roof.
  • Key features: Large roof windows (centre pivot, top-hung, or cabrio balcony options) that bring in light and ventilation. Conservation roof windows mimic traditional styles for listed buildings while offering modern features.
  • Benefits: Affordable, minimal disruption and quick installation, improved energy efficiency due to loft insulation.
  • Things to consider:
    • Suitability: Homes with pitched roofs, ideally with a pitch between 15 and 90 degrees.
    • Head height: Velux conversions require at least 2.2 meters of headroom from floor joist to ridge beam. Lowering the floor (ceiling below) can create more headroom, but this involves structural changes. Consider the cost comparison with a dormer loft conversion before deciding.
    • Planning permission: Most Velux conversions don’t require planning permission as they don’t alter the roofline. However, it’s recommended to apply if you live in a conservation area or a listed building.
    • Planning guidelines: Roof windows cannot extend more than 150mm beyond the roof slope. No alterations can be higher than the highest part of the existing roof. Side-facing windows must be obscure-glazed and non-opening, or openable only at more than 1.7 meters above floor level.
    • Cost: £1,150 – £1,350 per square metre.

Consulting Professionals

For the best outcome, consider a bespoke design from a professional architect. This ensures the loft conversion is legal, structurally sound, and meets all building regulations. Planning experts and structural engineers can be invaluable for navigating planning applications and adhering to building codes.

High-quality Victorian Loft Conversions by GDB

Dormer and Velux are just two of the basic loft conversion options available in the UK. They are popular due to their simple designs, versatility, and affordability. However, when expertly crafted, these loft conversions can enhance the overall aesthetics and value of your home.

Good Design & Build is a design-centric company specialising in Dormer and Velux loft conversions for Victorian and 1930s properties in London. Our projects begin with bespoke designs crafted around your lifestyle by our resident architects. We handle all the paperwork, including planning permission, building control applications, and method statements.

Request a free, no-obligation quote today.

Author: Amol

Amol is an architectural designer and has worked on hundreds of residential projects in London since 2008.Having done his M.Arch from the Glasgow School of Arts he gained valuable experience in London working in the construction industry managing high-end residential projects, before founding Good Design and Build in 2015.You will meet him for initial consultation and work closely with him during all stages of your project