The Caravan Sites and Control of Development Act 1960 isn't just for holiday parks. It's a powerful route for building granny annexes that can save you 20% on VAT and often avoid the need for planning permission. Here's how it works.
What Is the Caravan Act?
The Caravan Act defines what qualifies as a 'mobile home' or 'caravan' in UK law. A structure qualifies if it's designed to be movable and meets specific size requirements. This classification brings significant benefits for homeowners.
How Does It Apply to Granny Annexes?
A granny annexe can be built as a 'mobile home' under the Caravan Act if it meets these criteria:
- Designed to be movable in one or two sections
- Maximum dimensions: 20m long x 6.8m wide
- Used as residential accommodation ancillary to main dwelling
- Occupied by family members or dependents
- Sited within the curtilage of your property
The Zero VAT Benefit
This is huge. Buildings classified as caravans under the Act are zero-rated for VAT. What does this mean in practice?
- Standard building: £110,000 + £22,000 VAT = £132,000
- Caravan Act building: £110,000 + £0 VAT = £110,000
- You save: £22,000 (20% of the build cost)
- This saving applies to all labor and materials
Planning Permission Benefits
In many cases, Caravan Act structures don't require planning permission because:
- They're not considered 'permanent' structures
- They fall under permitted development for caravans
- They're ancillary to the main dwelling
- They can be removed if needed
Does 'Movable' Mean Lower Quality?
Absolutely not. This is the biggest misconception. A Caravan Act annexe is:
- Built to exactly the same standards as a permanent building
- Uses the same materials (brick, timber, insulation, windows)
- Has the same warranties and guarantees
- Feels identical to a traditional building when you're inside
- The 'movable' requirement is about design, not build quality
Can It Actually Be Moved?
Yes, though most never are. The requirement is that it's designed to be movable, not that you ever have to move it. In practice:
- Built in sections that can be separated
- Can be relocated within your property if needed
- Can be taken with you if you move house
- Can be sold or given to family members
- Most stay in place for decades, just like traditional buildings
What About Building Regulations?
Caravan Act structures are governed by British Standard BS 3632, which is specific to residential park homes. This standard covers:
- Structural integrity and safety
- Thermal insulation (often exceeds building regs)
- Electrical and plumbing standards
- Fire safety requirements
- Accessibility and space standards
Are There Any Downsides?
The Caravan Act route isn't right for everyone. Considerations include:
- Some mortgage providers prefer 'permanent' structures
- Resale value perception (though quality builds hold value)
- Size restrictions (max 20m x 6.8m)
- Must be ancillary to main dwelling, can't be sold separately
- Some very strict conservation areas may still require permission
Conclusion
For most families, the Caravan Act route is the smart choice. You save 20% on VAT immediately, often avoid planning delays, and get a building that's identical in quality and comfort to a traditional annexe. The 'mobile home' label is just legal classification, it doesn't mean lower quality or temporary structure. We build all our annexes to be Caravan Act compliant because it offers our customers the best value and fastest route to completion. Contact us to discuss whether this route is right for your project.