Can I rent out a garden annex?

This depends on your planning permission conditions. Some approvals restrict use to 'ancillary' accommodation for family only, while others permit independent letting. We recommend discussing your intentions with your installer at the feasibility stage.

How much does a garden annex cost?

Garden annexes typically start from £65,000 and range to £120,000+ depending on size, specification, and finishing level. While this is more than a standard garden room, it's significantly less than a traditional extension or buying additional property.

Can I rent out a garden annex?

This depends on your planning permission conditions. Some approvals restrict use to 'ancillary' accommodation for family only, while others permit independent letting. We recommend discussing your intentions with your installer at the feasibility stage.

How much does a garden annex cost?

Garden annexes typically start from £65,000 and range to £120,000+ depending on size, specification, and finishing level. While this is more than a standard garden room, it's significantly less than a traditional extension or buying additional property.

North Harrow · Middlesex

Garden Annexe in North Harrow

Serving the London Borough of Harrow planning area · North Harrow (Metropolitan line)

Self-contained living spaces perfect for guests, family, or rental income. Built to our 2026 Part L standard — adding £28,000–£68,000 to your North Harrow property. From £65,000.

0.15 W/m²K

U-value

£28,000–£68,000

Value uplift

25–40 days

Build time

£103

LDC fee

Trusted by homeowners in North Harrow

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Matched to North Harrow installers who know London Borough of Harrow planning requirements.

Garden Annexe in North Harrow, Middlesex

North Harrow is a predominantly residential area of largely 1930s semi-detached houses, sitting between Harrow town centre and Pinner to the north. It offers good tube connections, well-established family amenities, and the kind of regular, manageable rear gardens that are among the most practical for garden room installation. The uniformity of North Harrow's 1930s housing stock is an advantage for garden room planning: standardised plot depths of 50–70 feet, consistent boundary positions, and brick construction make site surveys quick and installations predictable. This translates to competitive pricing and reliable build timelines.

Why North Harrow Homeowners Choose This Build

Keep family close while maintaining independence and privacy

Cost-effective alternative to care homes or house extensions

Increase your property value significantly

Faster construction compared to traditional building extensions

Potential rental income stream (subject to planning)

2026 Technical Specification

Wall construction150mm SIPs panels

U-value (wall)0.15 W/m²K

GlazingA-rated argon-filled

Acoustic reduction40dB+ standard

Data infrastructureCAT6A (10Gbps ready)

ElectricsPart P compliant

FoundationsGround screws (no concrete)

Build time25–40 days

FSC-certified timber · Ground screw foundations · Just One Tree partner

Planning in North Harrow — London Borough of Harrow

North Harrow has no significant conservation area coverage across its main residential streets. Standard Permitted Development rules apply in the London Borough of Harrow. A Lawful Development Certificate (£103) is recommended for all builds to protect your investment at resale.

£103

LDC fee

2.5m

Max height (boundary)

50%

Max garden coverage

London Borough of Harrow Portal Full PD Guide 2026

How We Work in North Harrow

Feasibility Assessment

Check planning viability, site suitability, and building control requirements for habitable space.

Planning Application

Full management of the planning permission process, including design and submit documentation.

Building Control

Ensuring all regulations for habitable space are met, including fire safety and accessibility.

Complete Construction

Full build including all utilities, plumbing, electrics, and interior finishes.

See Completed Projects Near North Harrow

Real builds with specs, materials, and planning routes documented.

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Garden Annexe FAQs — North Harrow

Yes. Garden annexes intended for sleeping or living accommodation almost always require planning permission. Our partner installers manage the full application process on your behalf and can advise on the likelihood of approval in your specific borough.

“The team connected me with a fantastic installer who built my garden office in under 10 days. It's warm, quiet, and I love working from it every day.”

Sarah J.

Wimbledon, SW London · Garden Office

“Quick, professional, and totally transparent. I compared three quotes and picked the best one. My music studio is perfectly soundproofed.”

David M.

Highgate, North London · Music Studio