Garden Annexe for Adult Children

A garden annexe can offer an adult child a self-contained living space — typically a bedroom, kitchen and bathroom area — while keeping them close to family. For many households this works out considerably cheaper than renting in the same area, and gives the adult child a clearer route to saving a deposit or settling into a first professional role.

For the host household, an annexe often feels less disruptive than a large house extension and is much quicker to put in place. It also gives both sides genuine independence in a way that is hard to achieve from a converted spare bedroom.

• A recent graduate moving back home while starting a first job
• An adult child saving for a deposit in a high-cost local market
• A returning family member after a relationship change or a move between cities
• A remote-working adult child who needs a dedicated, quiet, separate space
• A short- to medium-term arrangement while a longer-term plan settles

• Compact second-hand static caravans: typically from around £25,000 for the unit
• New mid-range static caravans: typically £35,000–£55,000
• Larger lodges or BS3632 residential-spec models: typically £60,000–£120,000+
• Add delivery, base / groundworks, services and any planning costs on top
• Many households plan a sensible contingency, particularly if access or services are tight

Figures are general industry ranges, not a quote. Final costs depend on the unit specification, your plot and local site conditions.

A static caravan in the garden is treated differently from a built extension. How the space is used in planning terms — incidental use connected with the main house, rather than a separate dwelling — matters. So does the local authority’s view of the specific site, any conservation area, AONB, Green Belt or listed-building considerations.

We don’t offer planning permission or legal advice. We can flag the practical questions a planning team will typically ask, and point you towards a planning consultant or your local authority where appropriate.

For the host household

• Privacy for both sides — how positioning and screening affect this
• Utility costs and how these will be shared
• The intended length of the arrangement and what happens afterwards
• Any impact on the main house’s council-tax or insurance position (check with the relevant authorities)

For the adult child

• Realistic budget for their own running costs
• Distance from work, public transport and social life
• Storage, parking and post arrangements
• Their own longer-term housing plan

• Walk the proposed location together — access, ground level, distance to services, privacy
• Get a realistic cost envelope including groundworks, services and contingency
• Check the planning context for the specific site with the local authority
• Confirm the chosen unit size can physically reach the plot — gate widths, hedges, overhead cables
• Use the free suitability check below to get a planning-aware steer before committing