Garden Annexes
Design & Build
London

London Garden Granny Annexes & Garden Rooms Design & Build

Celtic Mini

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London Garden Granny Annexes & Garden Rooms Design & Build

Celtic

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London Garden Granny Annexes & Garden Rooms Design & Build

Celtic Plus

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Residential-Grade Garden Annexes Design & Build Across Greater London

Celtio designs and delivers modular garden annexes, granny annexes and insulated garden rooms across Greater London. Built using advanced CLT timber construction and precision off-site manufacturing, our structures are engineered for year-round comfort, energy efficiency and long-term durability. Designed within Caravan Act dimensional limits where applicable, our garden annexes provide compliant, self-contained living space suited to residential properties in outer London boroughs.

10 Year Warranty

BS 3632:2023 Compliant

Predictable Scope

Energy Efficient

Minimal Site Disruption

London Garden Granny Annexes & Garden Rooms Design & Build
London Garden Granny Annexes & Garden Rooms Design & Build
London Garden Granny Annexes & Garden Rooms Design & Build
London Garden Granny Annexes & Garden Rooms Design & Build
London Garden Granny Annexes & Garden Rooms Design & Build
London Garden Granny Annexes & Garden Rooms Design & Build

High-Performance Garden Rooms and Granny Annexes Installation in London

Demand for garden annexes in London continues to grow as homeowners seek multigenerational living solutions, independent accommodation and flexible work-from-home space. Rising property prices and limited space make modular garden annexes an efficient way to create additional living areas without relocating. Our garden annexes in London are designed to maximise usable space while remaining compliant with Caravan Act dimensional limits where applicable.

Our modular granny annexes for London are fully insulated, self-contained and built to residential performance standards, offering durable alternatives to lightweight garden buildings. Each unit integrates high-spec wall, roof and floor assemblies, reduced thermal bridging and controlled airtightness to ensure consistent internal comfort throughout the year. This delivers energy-efficient, year-round living suited to permanent occupation rather than seasonal use.

Using Cross-Laminated Timber panels, our modular garden rooms provide structural stability and long-term reliability within compact residential plots. Off-site manufacturing ensures precise build quality and faster on-site installation, minimising disruption in established neighbourhoods. From one-bedroom granny annexes to larger self-contained garden lodges, our CLT modular systems are engineered for compliance, sustainability and long-term property value enhancement across Greater London.

We cover the following areas in Greater London

  • We supply modular garden annexes and insulated garden rooms in Richmond upon Thames, supporting independent living within established residential neighbourhoods.

  • We deliver granny annexes and garden rooms in Barnet, designed for compliant installation and year-round use.

  • We install residential-grade garden annexes in Bromley, engineered using advanced CLT construction for durability and thermal efficiency.

  • We provide modular granny annex solutions in Croydon, tailored to suburban plots and local planning considerations.

  • We supply fully insulated garden rooms in Harrow, built for structural stability and long-term performance.

  • We deliver self-contained garden annexes in Kingston upon Thames, supporting multigenerational living and property value growth.

  • We install modular garden buildings in Enfield, designed within Caravan Act limits where applicable.

  • We provide energy-efficient granny annexes and garden rooms in Hillingdon, engineered for sustainable residential use.

Speak to us

Get in touch

If you would like to discuss your project, request specifications, or explore suitable configurations, our team is ready to assist. Get in touch to arrange a consultation and take the next step toward modular living built around your requirements.