What is a Hip to Gable Loft Conversion?

A hip to gable conversion involves extending the sloping side (hipped) roof of a property to create a vertical gable end. This enlarges the loft space, making it suitable for a full-sized room (like a bedroom with en suite or even two smaller rooms).

Often combined with a rear dormer for even more space and light.

Best Suited For

• Semi-detached houses
• End-of-terrace houses
• Detached houses with multiple hipped sides (you can do a double hip to gable)

Key Benefits

• Maximizes headroom and usable space
• Makes a cramped loft functional (perfect for master bedrooms or office)
• Blends well with existing house structure
• Boosts property value

Things to Consider

• Not typically suitable for mid-terrace homes
• More structural work than a dormer = higher cost
• May affect symmetry if attached to another house (important in conservation areas)

Planning Permission

Often falls under Permitted Development, but check local authority rules.

Planning permission needed if:

• You live in a conservation area or AONB
• The extension exceeds 40m³ (terraced) or 50m³ (semi/detached)

Building Regulations

Always required:

• Structural strength of the new floor
• Fire safety (fire doors, escape windows, etc.)
• Stairs, insulation, soundproofing, etc.

Estimated Cost (UK 2025)

£40,000–£65,000 (hip to gable only)

With a rear dormer: £55,000–£80,000+

Popular Uses

• Large master bedroom with en suite
• Home office and guest room combo
• Kids’ bedrooms with play/study areas