Senior Tiny Living UK 2026: Accessibility, Planning, and "Granny Annex" Laws

Downsizing is often about staying close to family while keeping privacy, safety, and independence. In the UK, that typically means choosing between a mobile “caravan”‑type unit within the curtilage of a home, or a fixed garden annexe that may need planning consent and building regulations approval. Understanding the legal definitions, accessibility standards, and cost drivers makes decisions clearer for seniors and carers.

VAT on mobile annexes: when can it be 0%?

Talk of “0% VAT” is common, but the rules are narrow. Most mobile annexes supplied as caravans attract either the standard 20% VAT or, if they are “qualifying caravans” built to residential standards such as BS 3632, a reduced 5% rate may apply. Zero‑rating generally applies only in specific circumstances (for example, certain works for disabled people under VAT relief rules, or the construction of an entirely new qualifying dwelling). A mobile annexe with a bathroom and kitchen can still be a “caravan” for VAT, but zero‑rating is not automatic. Keep evidence of specifications, intended use, and any disability‑related adaptations, and seek written confirmation from your supplier or a VAT specialist before you rely on a particular rate.

The Caravan Act route for a garden annexe

The Caravan Sites and Control of Development Act 1960 and the Caravan Sites Act 1968 define single and twin‑unit caravans. To qualify, the unit must be capable of being moved by road (in one piece or in two sections that bolt together) and must not exceed roughly 20m long, 6.8m wide, and 3.05m high. If sited within the curtilage of a dwelling and used ancillary to the main house (not as a separate independent home), many councils accept that no planning permission is needed, as this is use of land rather than operational development. However, rules on residential use are strict: independent occupation normally needs planning permission. To reduce risk, many households apply for a Certificate of Lawfulness for Proposed Use (section 192) to confirm the siting and ancillary use in writing. Always check local policies and any Article 4 Directions in your area.

2026 accessibility: applying M4(2) in small footprints

Part M’s optional M4(2) “accessible and adaptable dwellings” standard influences many new housing permissions, and its principles translate well to compact living—even when formal building regulations do not apply to a mobile caravan. For seniors, key features include step‑free access with firm, level routes; clear door widths and turning circles; a ground‑floor bedroom; and a bathroom sized for future grab rails or a level‑access shower. Plan for 900mm+ corridors where possible, low thresholds, reinforced walls in bathrooms, reachable switches and sockets (450–1200mm), and provisions for hoists or carers’ circulation. Even modest tweaks—sliding doors, pocket storage, non‑slip flooring, contrasting edges—meaningfully improve safety and independence.

What is driving the UK small‑home boom in 2026?

Several forces converge. Families want multigenerational arrangements without moving far, while older adults prioritise manageable spaces with lower running costs. High house prices and mortgage pressures push interest toward compact, energy‑efficient accommodation. Councils are familiar with garden annex proposals and mobile units, making processes clearer than a decade ago. Prefabrication shortens build time and disruption at the main house. Sustainability goals, better insulation standards (for example BS 3632 park‑home specs), and interest in local services for care support all add momentum. Together, these trends make small, accessible homes a pragmatic route to age in place.

What do small homes cost in the UK today?

Budgets vary by route: mobile caravan‑type units often have predictable shell prices plus transport and siting, while fixed garden annexes add groundworks, utilities, and building control. Typical extras include delivery (£1,500–£5,000 depending on distance and access), foundations and services (£8,000–£25,000+), planning or lawful‑use applications (£200–£2,000+ including drawings), and professional fees. VAT treatment depends on specification and use; many caravan‑type units qualify for the 5% rate, while fixed annexes commonly attract 20% on materials and services unless a specific relief applies. The figures below reflect typical publicly advertised ranges and quotes from UK providers as of late 2024.

Prices, rates, or cost estimates mentioned in this article are based on the latest available information but may change over time. Independent research is advised before making financial decisions.

Planning and “granny annexe” laws in practice

For a fixed annexe used as a self‑contained home, expect to apply for full planning permission; councils often condition occupancy to a family member and prevent sale as a separate dwelling. Building regulations approval is normally required, and some authorities encourage M4(2) where relevant. For caravan‑type units used ancillary to the main dwelling, planning permission may not be required, but the unit must remain incidental/ancillary in practice—separate post, utility meters, and leasing arrangements can signal independent use. Many households also explore the Council Tax family annexe discount, available in defined circumstances for relatives living in an annexe. Early pre‑application discussions with the local planning authority and clear evidence of ancillary use reduce uncertainty.

In summary, seniors considering compact living have three levers to balance: the legal route (caravan versus fixed annexe), the accessibility standard aimed for (adopting M4(2) principles even when not mandatory), and the total cost envelope. With careful planning, documented compliance, and realistic allowances for site works and VAT, a small, well‑designed home in the garden can support independence while keeping family close.