Static Caravan vs House Extension Cost UK

A traditional extension adds enclosed living space to the existing house, while a static caravan or lodge sits separately in the garden as additional accommodation connected with the main home. The two options behave very differently on cost, time, disruption and long-term flexibility.

There is no single “cheaper” answer. The honest comparison depends on specification, groundworks, services, planning context and how long the space is intended to be used. Treat the ranges on this page as indicative starting points — not quotes.

Static caravan as a garden annex

• Compact second-hand static caravans typically start from around £25,000 for the unit itself
• New mid-range static caravans typically sit in the £35,000–£55,000 range
• Larger lodges or BS3632 residential-spec models can move into the £60,000–£120,000+ range
• Add delivery, siting, base / groundworks, services connection and any planning costs on top
• Many families plan a sensible contingency for unexpected groundworks or access work

Traditional house extension

• A single-storey rear extension in the UK is commonly quoted in the £2,000–£3,500+ per m² range, depending on region and specification
• A modest 20m² single-storey extension can therefore land roughly in the £40,000–£70,000+ range, before fit-out
• Two-storey extensions, complex roofs or kitchen/bathroom fit-outs push costs up further
• Architect, structural engineer, building control and planning fees are additional
• Disruption to the main house and a longer build period are also part of the real cost

These figures are general market ranges drawn from typical UK industry guidance and are not a quote for your specific site.

Static caravans and lodges can often be specified, delivered and sited within a few weeks once the site is ready and planning is settled. Traditional extensions, by contrast, often involve design, planning, building regulations, structural work and fit-out, with a build phase commonly running for several months.

Both timelines depend heavily on planning, access, weather and contractor availability. A static caravan being on a plot quickly doesn’t mean planning questions have gone away — those still need to be considered.

Planning context is one of the biggest differences. A house extension is typically governed by permitted development rules or a full planning application. A static caravan in a garden is treated differently in planning terms, and how it is used — incidental use connected with the main house vs. a separate dwelling — matters a great deal.

We do not provide planning permission or legal advice. We can flag the practical questions a planning team is likely to ask, and point you towards a planning consultant or your local authority where appropriate.

• Width and height of the route from the road to the siting position
• Ground conditions and the type of base required (concrete pad, gravel raft, piled base)
• Distance to mains water, drainage and electricity — long service runs add cost
• Whether the unit is delivered as a single section or split (twin-unit lodges)
• Any tree, hedge, fence or boundary work required to allow delivery
• Disposal of waste material and reinstatement of any temporary access

• A realistic budget envelope including groundworks, services and contingency — not just the unit price
• How the space is intended to be used (occasional visits vs. long-term resident)
• How long it needs to last — a short-term arrangement is a different decision to a permanent one
• Local planning context (conservation area, AONB, listed building, Green Belt)
• Access route and whether the chosen unit size can physically reach the plot

A free suitability check is a quick way to get a planning-aware, site-specific steer before committing.