Side return extensions are one of the most transformative home improvements for Victorian and Edwardian terraced houses in London. This guide covers everything you need to know about reclaiming this “dead space” to create a stunning, full-width kitchen.
What Is a Side Return?
A side return is the narrow passage between your house and your neighbor’s property, typically 1-1.5 metres wide. In Victorian and Edwardian terraces, this space runs the full depth of the property but is often unused except for bins and bike storage.
Why Side Returns Exist
These passages were originally designed for:
- Natural ventilation before cavity walls
- Access to the garden without walking through the house
- Coal delivery access to rear coal sheds
- Light to side-facing windows
Costs of Side Return Extensions
Typical Size & Budget
Most side return extensions are 10-15 square metres. In London, expect to pay:
- Budget build: £25,000-£35,000 (£1,800-£2,200/m²)
- Mid-range: £35,000-£50,000 (£2,200-£3,000/m²)
- Premium: £50,000-£70,000+ (£3,000-£4,500/m²)
What Affects Costs?
- Structural complexity: Removing load-bearing walls requires steel beams (£3,000-£6,000)
- Glazing choices: Crittal-style vs. standard aluminium (£2,000-£8,000 difference)
- Roof type: Flat roof with lantern vs. pitched (£3,000-£6,000 difference)
- Kitchen quality: Can add £15,000-£40,000 to total project
Planning Permission
Do You Need It?
Not in most cases! Side return extensions under Permitted Development can proceed without planning if:
- Single storey only
- Maximum 4m high
- Not within 2m of boundary if over 3m high
- Materials match existing house
- Not in conservation area (see below)
Conservation Areas
If your property is in a conservation area, you WILL need planning permission for side extensions. Article 4 Directions remove Permitted Development rights. Check your council’s planning portal to confirm.
Design Considerations
Glazing Options
1. Crittal-Style Windows
Industrial-look steel frames, hugely popular. Pros: Stunning aesthetics, maximum light, slimline frames. Cons: £4,000-£10,000 vs. £2,000-£4,000 for aluminium.
2. Sliding Doors
Rather than bi-folds, consider large sliding panels. Often cheaper (£2,500-£5,000) and fewer moving parts to maintain.
3. Fixed Glazing + Windows
Most cost-effective. Fixed glass panels with smaller opening windows for ventilation (£1,500-£3,000).
Roof Options
Flat Roof with Rooflight: Modern, clean lines. Add a skylight or roof lantern for extra light. Cost: £4,000-£10,000.
Pitched Roof: Traditional look, better for period properties in conservation areas. Cost: £6,000-£12,000.
Return on Investment
Side return extensions typically add 12-18% to property value in desirable London areas. For a £550,000 property:
- 15% increase = £82,500 added value
- Typical spend = £40,000-£50,000
- Net gain = £30,000-£40,000
Common Mistakes to Avoid
- Insufficient insulation: Building regs require high U-values. Don’t skimp.
- Poor drainage planning: Ensure rain water soaks away properly.
- Ignoring Party Wall Act: You must notify neighbors 2 months before work starts.
- Cheap glazing: Budget frames look dated within 5 years.
Ready to Start Your Project?
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