Bespoke Garden Rooms, Garden Offices and Annexes
Designed around your garden, manufactured in our Watford factory and installed by our own team. Pecasa serves homeowners across London, Hertfordshire and the rest of the UK.
120+Completed Projects
100+ Yearscombined construction experience
Made in Britain member
10-year IWA insurance-backed warrantyon qualifying projects
Pecasa Ltd is a garden room company based in Watford, Hertfordshire. Since 2017 we have completed more than 120 bespoke garden rooms, garden offices and garden annexes. We manufacture our own Structural Insulated Panels (SIPs) in Watford, and our core team manages every build. Our team brings more than 100 years of combined construction experience.
Every building is designed from scratch around your garden, your home and the way you will use the space. We do not sell flat-pack kits or off-the-shelf models. Buildings typically range from 4 m² to 90 m², and our most popular size is around 30 m².
Why homeowners choose Pecasa
Truly bespoke garden room design
Size, layout, roof form, glazing and finishes are designed for your garden and planning position.
SIP panels made in our own factory
Walls, floor and roof are built from SIPs. EPS70 insulation is standard, available from 75 mm to 250 mm, and PIR insulation is available as an upgrade, for genuine year-round comfort.
British-made Radix ground screw foundations
Radix ground screws are our standard foundation system, subject to ground conditions and site suitability.
A finished room, not a shell
Plasterboard walls with a tape-and-joint finish, 12 mm premium laminate flooring, lighting, electrics and Cortizo aluminium doors and windows come as standard.
Clear, VAT-inclusive prices
Prices start from £23,000 including VAT for a 3 m × 2.8 m garden room. Every Pecasa building is bespoke, and your final quotation reflects the design, specification and site requirements. You will also receive a free 3D design and a written, VAT-inclusive quotation, normally within seven days of your survey. Quotations remain valid for three months.
Long-term protection
A 10-year IWA insurance-backed warranty on qualifying projects, subject to registration and policy terms. We also usually offer a free aftercare visit around six months after handover.
Luxury garden rooms, specified properly
Luxury is in the details you live with every day. Choose from Millboard Board & Batten or Shadow Line, cedar, Shou Sugi Ban charred timber, Durasid Foresta and Ceta composite cladding. Add slim Cortizo aluminium French, bi-fold or sliding doors, with triple glazing if you want it. Upgrade with Samsung or Mitsubishi air conditioning controlled by Wi-Fi, acoustic insulation for a studio or office, a shower room or a kitchenette.
What We Build
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Garden rooms
Fully insulated spaces for relaxing, entertaining, hobbies or family use.
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Garden offices
Quiet, connected workspaces for working from home.
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Garden annexes
Create a bespoke garden annexe for family accommodation or guests, subject to the necessary planning and building regulation approvals.
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Garden rooms with a toilet or bathroom
For gyms, guest rooms, studios and home businesses.
How much does a garden room cost?
Prices start from £23,000 including VAT for a 3 m × 2.8 m garden room. Every Pecasa building is bespoke, and your final quotation reflects the design, specification and site requirements. Upgrades such as air conditioning, a shower room or decking are priced in your quotation. See the full price list and what is included.
Bespoke garden rooms in London
Much of our work is in London, from garden offices in Wimbledon to an annexe with a gym, kitchen and WC in Hendon. London gardens often have no side access, so where the route is suitable we carry components through the house. Every London project starts with a free survey that checks access, boundaries and relevant planning considerations.
Where we work
We are based at our factory in Watford, close to North London and Hertfordshire, and we serve customers throughout the UK. Projects in Europe can be arranged by agreement.
Our process
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Free survey
A member of our survey team visits, measures the garden, checks access and discusses how you will use the room. It usually takes 10–30 minutes.
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Manufacture
Once you confirm your order, we manufacture your SIP panels and prepare the building at our Watford factory.
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Installation
For garden rooms up to 16 m², we guarantee installation within two weeks (10 working days) of the start of work on site, subject to the agreed specification, site access and weather. Typical working days on site:
- 14–16 m² garden room: 8–10 working days
- Up to 30 m²: 10–12 working days
- Annexe: 14–16 working days
Larger rooms and annexes are scheduled individually, and your quotation confirms the installation period for your project.
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Aftercare
You receive care guidance for your chosen materials, and we usually offer a free aftercare visit around six months after handover.
Free 3D garden room designer
Design and price your garden room in around 5 minutes. Choose your style, size and specification to get an instant indicative price and 3D design, then save your designs to return to later.
You will also receive a free 3D design and a written, VAT-inclusive quotation, normally within seven days of your survey.
Garden annexes
Add independent living space with a bespoke garden annexe, ideal for multi-generational living or guest accommodation, subject to the necessary planning and building regulation approvals.
Perfect for:
- Family accommodation
- Guest suites
- Independent living spaces
The Pecasa Build Standard
Every Pecasa building is engineered for durability, efficiency and long-term performance.
Our premium build includes:
- Structural Insulated Panels (SIPs) construction
- Ground screw foundation system
- High-performance EPDM roofing
- Plasterboard walls with a tape-and-joint finish
- Integrated lighting and electrics
- 12 mm premium laminate flooring
- Modern doors and glazing
Result: a garden building that performs like a true extension of your home.
Need help designing your garden room?
Contact us to book your free design consultation.
Meet the team
Patrick Halili, Director. Patrick has 28 years of experience in construction and leads Pecasa’s surveys, design and builds. He studied technical engineering for three years before beginning his career in construction.
Pecasa directly employs eight people, including carpenters, an electrical engineer, a logistics and site manager, an interior finishing specialist and an office manager. Our core team manages the build, with qualified specialists used where required.
Patrick
Surveyor & Garden Room Expert
Patrick is Pecasa’s professional surveyor and garden room specialist. He has extensive experience in surveying, design, and construction of premium garden rooms, ensuring each project is tailored to the highest standards.
Mihail
Carpenter & Wood Expert
Mihail is Pecasa’s master craftsman with extensive expertise in carpentry and woodwork. He brings precision and skill to every garden room build, ensuring each structure is crafted with the highest standards of quality and workmanship.
Tudor
Carpenter
With years of experience in carpentry and construction, Tudor is an important part of the Pecasa team. His craftsmanship, attention to detail, and dedication to quality help ensure every garden room is built to the highest standard.
Tany
Electrical Engineer
With extensive experience in electrical installations, Tany ensures every Pecasa garden room is fitted with safe, efficient, and high-quality electrical systems. His expertise helps deliver reliable lighting, power, and heating solutions that make each space fully functional all year round.
Frequently Asked Questions
For garden rooms up to 16 m², we guarantee installation within two weeks (10 working days) of the start of work on site, subject to the agreed specification, site access and weather. Typical working days on site: • 14–16 m² garden room: 8–10 working days, • Up to 30 m²: 10–12 working days, • Annexe: 14–16 working days, Larger rooms and annexes are scheduled individually, and your quotation confirms the installation period for your project.
In England, many garden rooms used for purposes incidental to the house, such as an office, gym or studio, fall within permitted development and do not need planning permission, provided they meet the relevant size, height and location limits. For example, a building within 2 m of a boundary must be no more than 2.5 m high under England’s guidance. Planning rules differ elsewhere in the UK. Flats, listed buildings, conservation areas and self-contained annexes have different rules. We give guidance at your free survey and can recommend an external planning consultant where an application is needed.
Yes. SIP walls, floor and roof, Cortizo aluminium glazing and an EPDM roof create a well-insulated building. Air conditioning or heating can be added and is specified in your quotation.
SIP construction, Radix ground screw foundations, an EPDM roof, Cortizo aluminium doors and windows, external cladding, plasterboard walls with a tape-and-joint finish, 12 mm premium laminate flooring, and lighting and electrics designed to your requirements. Site clearance, electrical supply connections to the building, water and drainage connections, skips and parking permits are priced separately.
Prices start from £23,000 including VAT for a 3 m × 2.8 m garden room. Every Pecasa building is bespoke, and your final quotation reflects the design, specification and site requirements.
We are based in Watford and serve customers across London, Hertfordshire and the rest of the UK. Projects in Europe can be arranged by agreement.
Qualifying projects receive a 10-year IWA insurance-backed warranty, subject to registration and the policy terms. Manufacturer warranties apply separately to products such as doors, windows and air-conditioning units.