Why Garden Annexes Make Sense in London

Three London-specific drivers behind the rise of garden annexes:

1. The cost of care

Residential care in London now costs £1,200–£1,800 per week. A purpose-built garden annexe to keep an elderly parent close — independent but supported — typically costs less than two years of care fees and lasts decades.

2. The cost of renting

Average one-bedroom rent in London is now £1,800+ per month. Many families now host adult children at home while they save for a deposit. A garden annexe gives both sides the independence they want.

3. The cost of moving

Stamp duty, estate agent fees, removal costs and the difference between a 3-bed and a 4-bed home in London regularly exceeds £80,000–£150,000. A garden annexe usually delivers more usable space for less.

London-Specific Planning Considerations

Planning rules vary between London boroughs and individual sites. Key considerations:

• Permitted Development — Many garden annexes used as ancillary family accommodation fall within Permitted Development, particularly outside conservation areas and Article 4 zones.
• Conservation areas — Boroughs like Camden, Westminster, Islington and parts of Hackney have strict conservation rules. Annexes are still buildable but may need full planning.
• Listed buildings — Listed status means full planning consent is required and design must be sympathetic. We have experience with listed-building applications across London.
• Article 4 directions — Some London boroughs have removed certain PD rights. We check this in the survey.
• Independent dwelling vs ancillary use — Annexes used as separate independent dwellings (e.g. for rental) face stricter planning than annexes used by family members.

We handle planning consultation as part of every London annexe project. The cost of any required planning application is included in our quotation.

Garden Annexe Configurations

Studio Annexe (5x4m / 20 sqm)

Open-plan living/sleeping with a small kitchenette and separate bathroom. Ideal for a single elderly parent or a young adult child. Most affordable configuration.

One-Bedroom Annexe (6x4m / 24 sqm)

Separate bedroom, open-plan living/kitchen, bathroom. Comfortable long-term accommodation for one person or a couple. Most popular configuration.

Two-Bedroom Annexe (7x5m / 35 sqm)

Two separate bedrooms, living room, kitchen, bathroom. For couples with a guest room, or two unrelated occupants (e.g. two adult children). Typically requires planning consent.

Accessibility-Designed Annexe

Any of the above, designed with mobility considerations: level threshold, wider doorways (900mm+), walk-in shower with grab rails, lower kitchen worktops, slip-resistant flooring, emergency call connection to main house.