Garden Office, Room & Studio Specialists · London

A Garden Office You Use Every Day

Permanent, fully insulated garden offices, rooms and studios — built to be worked in all year, not a summer house that sits empty by October. Proper foundations, an insulated envelope, heating, power, data and a full interior fit-out, designed and built by one team under one fixed-price contract, usually within permitted development.

A Single Fixed-Price Contract
Designed and built in-house
Foundations & baseIncluded
Insulated envelopeIncluded
Heating & coolingIncluded
Power, lighting & dataIncluded
Interior fit-outIncluded
Aftercare warranty10 years
103+
Completed Projects
RIBA
Architect Partners
Insulated
Year-Round Build
Permitted
Development Often
NICEIC
Certified Electrics
Heat
Pump
Heating & Cooling
£10M
Fully Insured
RICS
Chartered Surveyors
£25k£120k
Compact Office to
Large Studio
48
Build Programme
Weeks
All Year
Insulated & Heated
100%
Fixed-Price
No Hidden Cost-Plus

A Proper Room at the End of the Garden

Working from home has made the garden office one of the most wanted additions to a London home — and one of the most uneven in quality. At one end are flat-pack cabins dressed up as offices: single-skin walls, token insulation, a roof that bakes in summer and a floor that is cold by November. At the other is a properly engineered, fully insulated building that you can work in comfortably every day of the year, that holds its value, and that looks like it belongs in the garden. This page is for the latter.

A garden office, garden room or garden studio from us is a permanent building, not a product wheeled in on a trailer. It has real foundations, an insulated floor, wall and roof envelope, double or triple glazing, heating and cooling, full power and data, and an interior finished to the standard of a room in the house. Whether you need a quiet office for video calls, a studio for creative work, a gym, a treatment room or a flexible space that does several jobs, we design and build it around the use you actually have in mind.

Because we are a design-and-build contractor, the whole thing comes from one team under one fixed-price contract — the groundworks, the structure, the services run from the house, and the fit-out. There is no separating “the cabin supplier” from “the electrician” from “the groundworker”; we are responsible for all of it, including getting power and (where you want it) water cleanly across the garden and connected.

Most garden offices can be built under Permitted Development, which keeps the process simple, though the rules on height, position and use matter and are easy to fall foul of. We check your specific garden, advise on the most likely route, and manage any planning application if one is needed. Where you actually need self-contained accommodation for family rather than an office, that is a granny annexe, which we also build — we will tell you honestly which your plans require.

We build garden offices and studios across NW3, NW8, NW11, N6 and SW London — in long terraced gardens, behind semis and in larger plots — each engineered for the ground it sits on and finished to match how it will be used.

Six Ways to Use a Garden Building

The structure is the same high standard; the fit-out and services are designed around what you will actually do in it.

Work From Home

Home Office

A quiet, well-lit, well-connected room for focused work and video calls — separate from the house, with no commute and no spare bedroom sacrificed. The most-requested use, and the one we optimise for acoustics and daylight.

Key needsData, light, quiet
Typical size8–14m²
Creative Space

Garden Studio

A light-filled studio for art, music, design or making — with the glazing, power and (for music) acoustic treatment the work needs. Larger glazing and considered north or roof light for consistent daylight.

Key needsDaylight, power
Typical size12–20m²
Health & Fitness

Garden Gym

A reinforced floor for equipment, robust ventilation, mirrors, and the power and cooling a workout space needs. A dedicated gym that keeps the kit out of a bedroom and is ready whenever you are.

Key needsFloor, ventilation
Typical size14–24m²
Office + Facilities

Studio With Shower / WC

An office or studio with its own WC, shower and kitchenette — so you do not need to traipse back to the house, and the building works as a true self-sufficient space for long days or guests.

Key needsDrainage, water
Typical size16–24m²
Wellbeing

Treatment / Therapy Room

A calm, private room for treatments, consultations or therapy — with appropriate access, a WC, gentle lighting and the discretion a separate garden building provides. Popular with practitioners working from home.

Key needsAccess, WC, privacy
Typical size12–18m²
Flexible

Multi-Use Garden Room

A room that does several jobs — office by day, guest space, playroom or hobby room — with the layout, storage and services to switch between them. The all-rounder for families who want flexible extra space.

Key needsFlexible layout
Typical size14–24m²

What a Garden Office Actually Includes

A year-round garden building is a proper construction project. Every element below is delivered and warranted under one fixed-price agreement.

Groundworks & Foundations

Site clearance and an engineered foundation matched to your ground — insulated concrete raft, ground screws or mini-piles — assessed against soil, drainage and any nearby trees, so the building never settles, cracks or twists.

Structure & Frame

A robust timber or steel frame engineered to last decades, not seasons — with a breathable, weatherproof build-up and a roof designed for proper drainage and (where you want it) a green or sedum finish.

Full Insulated Envelope

Insulation in the floor, walls and roof to meet or exceed Building Regulations, with an airtight, draught-free construction — the single biggest factor in whether the room is usable in winter and cool in summer.

Glazing & Doors

Double or triple-glazed windows and sliding or bi-fold doors, positioned for light, view and privacy, with solar control where the building faces the sun — bringing the garden in without overheating the room.

Cladding & Roof

External cladding in timber, composite or render to suit your garden and any planning context, with a durable, well-detailed roof — the finish that decides whether the building looks designed or like a kit.

Power, Lighting & Data

A dedicated armoured supply from the house, NICEIC-certified circuits, LED lighting, ample sockets with USB, and hard-wired data or a Wi-Fi access point — a reliable connection that holds up on video calls.

Heating & Cooling

An air-source heat pump that both heats and cools efficiently, or controlled electric panel heating — so the room is warm within minutes on a cold morning and comfortable on the hottest afternoon.

Plumbing (Optional)

Where you want a WC, shower or kitchenette, the drainage connection, water supply and fittings — planned early, because drainage across a garden is far easier designed in than added later.

Interior Fit-Out

Plastered or panelled walls, quality flooring, built-in joinery and storage, and decoration to the standard of a room in the house — not bare ply and a strip light.

Landscaping & Path

The path, terrace or steps connecting the building to the house, and making-good of the garden around it — so the office is integrated into the garden, not marooned across a muddy lawn.

Planning & Approvals

We check whether your build is Permitted Development and, where it is not, prepare and manage the planning application — plus a Lawful Development Certificate where it confirms the build is lawful for the future.

Snagging & Aftercare

A two-stage snag, commissioning of the heating and electrics, a 12-month defects period, a 10-year workmanship warranty and a six-month service visit.

What Makes a Garden Office Worth Building

The difference between a year-round room and an expensive shed comes down to six things — all decided before the first board goes up.

i.

Real Foundations

An engineered base matched to the ground and trees, so the building does not settle or twist. The invisible part that, skimped, causes doors to jam and frames to crack within a couple of winters.

ii.

A Full Insulated Envelope

Insulation in floor, walls and roof with an airtight build-up — the reason a proper garden office is comfortable in January, where a single-skin cabin is unusable for half the year.

iii.

Glazing That Controls Heat

Double or triple glazing positioned and specified for light without overheating — a south-facing glass box bakes in summer unless the glazing and shading are designed properly.

iv.

Heating and Cooling

A heat pump or good electric heating with proper controls, so the room reaches temperature fast and runs efficiently — comfort you will use, not a heater you fight with.

v.

A Reliable Connection

A dedicated power supply and hard-wired or strong wireless data — because a garden office is only useful if the laptop charges and the video call holds.

vi.

A Finish Worth Sitting In

An interior finished to the standard of the house — plaster, good flooring, built-in storage — so it feels like a room you want to spend the day in, not a workshop.

Eight Stages, From Brief to Handover

A garden building is a contained project, but it rewards the same disciplined process as any of our work.

0
Stage 0 · Brief

Free Consultation

We discuss what you want the building to do, where it should sit, and your budget — at your home so we can see the garden. No charge, no obligation.

Week 0 · Free
1
Stage 1 · Survey

Garden & Ground Survey

A survey of the garden, ground conditions, drainage, trees and access, plus the route for power and any water — the basis for the foundation design and a firm price.

Within 1–2 weeks
2
Stage 2 · Design

Design & 3D View

The size, layout, glazing and external finish developed and presented with a 3D view, refined with you, and checked against Permitted Development limits.

2–4 weeks
3
Stage 3 · Approvals

Permitted Development / Planning

A Lawful Development Certificate where the build is Permitted Development, or a full planning application where it is not — prepared and managed by us.

0–10 weeks (route-dependent)
4
Stage 4 · Foundations

Groundworks & Base

Site clearance, drainage and services trenching, and the engineered foundation laid and cured — the platform everything else depends on.

1–2 weeks
5
Stage 5 · Build

Structure, Envelope & Fit-Out

Frame, insulation, cladding, roof, glazing and doors, then first fix, plaster, second fix, heating, flooring and decoration. Weekly updates throughout.

4–8 weeks on site
6
Stage 6 · Handover

Commissioning & Handover

Heating and electrics commissioned, the path and landscaping completed, a joint snagging walk and handover of your finished building.

Completion
7
Stage 7 · Aftercare

Defects Period & Warranty

A 12-month defects period, a six-month service visit and a 10-year workmanship warranty.

12 months + 10-year warranty

Four Tiers, Honestly Drawn

What a garden office costs depends on size, glazing, services and finish. Here is how our four tiers differ.

Element
HeritageStandard
ConsideredHigh-End
ConnoisseurPremium
AtelierSuper-Prime
Foundations
Ground screws / slab
Insulated raft
Engineered raft / piles
Full engineered substructure
Insulation
Part L compliant
Enhanced, low cold-bridge
High-performance envelope
Near-Passivhaus, airtightness test
Glazing
Double-glazed
Larger double, solar control
Triple, sliding doors
Minimal-frame / bi-fold, frameless
Cladding
Treated timber
Composite or cedar
Charred timber / render
Bespoke, mixed materials
Heating / cooling
Electric panel heaters
Air-source heat pump
Heat pump + controls
Full climate control + MVHR
Interior
Painted plaster, vinyl floor
Plaster, engineered oak
Joinery, premium floor
Bespoke fit-out, feature finishes
Indicative cost
£25k–£40k
£40k–£60k
£60k–£90k
£90k–£120k+

Where Your Budget Actually Goes

For a representative high-end garden studio at around £55,000, here is the honest breakdown of where every pound is spent.

Structure & envelope
28%
Foundations & groundworks
14%
Glazing & doors
12%
Cladding & roof
10%
Electrics, data & heating
13%
Interior fit-out & flooring
10%
Landscaping & connection
6%
Design & management
5%
Contingency (held by client)
2%

The Engineering Behind the Building

A year-round garden building is built to the same principles as a house. Here is what is designed and installed.

Foundations & Structure

  • Base: Insulated reinforced raft, ground screws or mini-piles, designed to the ground conditions and tree proximity
  • Frame: Engineered timber or light-steel frame, designed for wind load and longevity
  • Roof: Warm flat or mono-pitch roof with single-ply or GRP membrane, designed for drainage; green roof optional
  • Drainage: Surface-water and (where applicable) foul drainage designed and connected correctly

Envelope & Performance

  • Insulation: Floor, wall and roof insulation to meet or exceed Building Regulations Part L
  • Airtightness: A sealed, draught-free build-up with a vapour control layer to prevent condensation
  • Glazing: Low-E double or argon triple glazing; solar-control glass on exposed elevations
  • Ventilation: Trickle or mechanical ventilation to keep air fresh and control humidity

Services

  • Power: SWA armoured cable from the house consumer unit or a dedicated sub-board, NICEIC-certified
  • Lighting: LED circuits, dimmable, with ample sockets and USB
  • Data: Hard-wired Cat6 or a wired-back Wi-Fi access point for a reliable connection
  • Heating: Air-source heat pump (heating and cooling) or controlled electric panel heating

Compliance

  • Permitted Development: Designed within outbuilding height, position and coverage limits where applicable
  • Building Regulations: Required where the building exceeds size thresholds, contains sleeping accommodation, or is close to a boundary
  • Electrical: Part P self-certified, with an electrical installation certificate
  • Lawful Development Certificate: Obtained to confirm the build is lawful, useful for future resale
A garden office is judged on a wet Tuesday in January. If it is warm in five minutes, the connection holds and the room is one you want to sit in, it was built properly. If not, it was a shed with ambition.
— Hampstead Renovations · Studio Statement

Planning & Permitted Development for Garden Buildings

Most garden offices can be built without a full planning application — but the rules are specific, and getting them wrong is costly.

A garden office is usually treated as an outbuilding, and outbuildings often fall under Permitted Development — meaning no full planning application is needed — provided they meet the conditions: single-storey, incidental to the enjoyment of the house, within height limits (generally 2.5m where within 2m of a boundary, otherwise up to 3m for a flat roof or 4m for a dual-pitched roof), and not covering more than 50% of the garden. We design within these limits where you want to keep it simple.

Permission is usually required in a Conservation Area or for a Listed building, where Permitted Development is restricted; if you exceed the size or height limits; or — importantly — if the building is to be used as self-contained living accommodation rather than a workspace incidental to the house. That last point is the one people most often get wrong: a garden office is an office; a place for family to live is a granny annexe, which needs planning permission and is assessed differently.

We check your specific garden, advise on the route, and obtain a Lawful Development Certificate where the build is Permitted Development — which is well worth having to prove the building is lawful when you come to sell — or prepare and manage a full planning application where one is needed. For an early budget, use the cost calculator, and see our garden rooms & outbuildings page for the wider range.

A Garden Studio, Week by Week

A representative programme for an insulated garden studio with a shower. Yours will differ by size and access, but this is what a properly run build looks like.

Week
Phase
Activity on Site
Pre
Design & Approvals
Design signed off, Lawful Development Certificate or planning obtained, materials ordered.
01
Groundworks
Site clearance, drainage and services trenching across the garden, foundation laid.
02
Structure
Frame erected, roof structure and membrane installed, building made weathertight.
03
Envelope
Insulation, cladding, windows and doors installed; external finish completed.
04
First Fix
Electrical and any plumbing first fix, heating, plasterboarding and skim.
05
Second Fix & Fit-Out
Lighting, sockets, heating commissioned, shower fitted, flooring laid, joinery installed.
06
Decoration & Landscaping
Decoration, the path and terrace, garden made good around the building.
06
Snag & Handover
Snag list resolved, commissioning, clean, certification and handover.

What Sets Our Garden Buildings Apart

There is a wide gulf between a flat-pack cabin and a building you work in for years. Here is what ours gives you.

i

Built Like a House

Real foundations, a full insulated envelope and proper services — a permanent building, not a product on a base.

ii

One Team, Whole Job

Groundworks, structure, services from the house and fit-out under one fixed-price contract — no separate cabin supplier and electrician to coordinate.

iii

Year-Round Comfort

Designed for January and July alike — insulation, glazing and heat-pump heating and cooling that make it genuinely usable every day.

iv

Planning Handled

We confirm Permitted Development, obtain a Lawful Development Certificate, or manage a full application — so the build is lawful and future-proof.

v

Directly-Employed Trades

Our core trades are PAYE staff — continuity of standard, not a rotating crew.

vi

£10M Insurance

Professional indemnity and public liability at £10M, well above industry standard.

vii

Reliable Connection

A dedicated supply and wired data — designed for working, not just lighting a room.

viii

10-Year Warranty

An insurance-backed workmanship warranty protecting the building long after completion.

Explore Related Garden & Space Projects

A garden office is one way to add space. Start here, or speak to us about the alternatives.

Garden Building Proof

Comparable projects and finishing standards across our work. Browse the case-study hub and the wider portfolio, and for advice on the right space-gain for your home, contact us.

Detailed Answers to the Questions That Matter

What is a garden office, and can I use it all year round?

A garden office is a permanent, insulated, fully serviced building in your garden, built to be used comfortably every day of the year — not a glorified shed. Ours are constructed with proper foundations, insulated walls, floor and roof to current standards, double or triple glazing, heating and cooling, power, lighting and data. That is the difference between a garden office you actually work in through January and a summer house that sits empty for half the year.

How much does a garden office cost in London in 2026?

As a guide for prime London: a compact insulated garden office of around 10–12m² typically runs £25,000–£40,000; a larger 15–20m² studio with a shower or kitchenette £45,000–£70,000; and a substantial garden building with multiple rooms and high-end fit-out £75,000–£120,000+. The variables are size, foundations, glazing, services and finish. Use the cost calculator for an early band, then we firm it up at survey.

Do I need planning permission for a garden office?

Many garden offices fall under Permitted Development for outbuildings, provided they are single-storey, used for purposes incidental to the house, sit within height limits (generally 2.5m to the eaves near a boundary, 4m overall for a dual-pitched roof) and do not cover more than 50% of the garden. Planning permission is usually needed in a Conservation Area, for a Listed property, if you exceed the limits, or if the building is to be used as self-contained living accommodation. We check your exact site and manage any application.

How long does it take to build a garden office?

Once designed and approved, a garden office is typically 4–8 weeks on site depending on size, foundations and fit-out — faster than most house works because it is a contained, off-the-critical-path build. Add 2–4 weeks of design beforehand, and a planning period only if Permitted Development does not apply. We give you a week-by-week programme before starting.

What foundations does a garden office need?

It depends on the ground and the size. Options range from a reinforced concrete slab or insulated raft, to ground screws (fast, low-disturbance and ideal for tricky access or tree-root areas), to mini-piles where the ground is poor. We assess the ground, drainage and any nearby trees at survey and specify foundations that will not move — the part that, done wrong, causes a garden building to crack and twist within a few years.

Can a garden office have a bathroom, kitchenette or be used as a gym?

Yes to all. We routinely add a WC and shower (which requires a drainage connection and is worth planning early), a kitchenette or tea point, and the reinforced floor, ventilation and power a home gym needs. A garden building can be an office, a studio, a gym, a treatment room or a guest space — we design the structure, services and ventilation around the use you have in mind.

How is a garden office insulated and heated for winter?

With a full insulated envelope — insulation in the floor, walls and roof to meet or exceed Building Regulations — double or triple glazing, and an airtight, draught-free construction. For heating and cooling we usually fit an air-source heat pump (air-conditioning unit) that both heats and cools efficiently, or electric panel heaters with good controls. Properly built and insulated, a garden office is warm in minutes and comfortable in any season.

Do you provide power, lighting, data and internet?

Yes — a dedicated armoured power supply run from the house consumer unit (or a new sub-board), full NICEIC-certified circuits, LED lighting, ample sockets with USB, and hard-wired data or a Wi-Fi access point so your connection is reliable for video calls. We plan the electrics around how you will use the room, including provision for a heat pump, charging and AV.

Can I use a garden office as a separate home or rent it out?

A garden office built under Permitted Development must be incidental to the main house — an office, studio or gym — not a separate, self-contained dwelling, and it cannot normally be let or sold separately. If you want self-contained accommodation for family, that is a granny annexe, which has its own planning route; see our granny annexe page. We will advise honestly on which your plans require so the building is lawful.

Does a garden office add value to my home?

A well-built, insulated, year-round garden office is increasingly sought-after in the London market — it adds genuinely usable space and answers the demand for working from home without sacrificing a bedroom. As with any improvement, quality is what holds value: a properly engineered, fully serviced garden building reads as an asset to a surveyor and a buyer, whereas a cheap uninsulated cabin does not. We build the former.
Client References

What Our Clients Say

★★★★★

“I would like to thank Ross and his team for their consistent commitment to quality and their unerring reliability. They delivered our property to specification and on time, proving to be an extremely effective, experienced, and proactive contractor.”

James Ward — Investment Director, Belgravia
★★★★★

“We have worked with Ross and his company many times. They are extremely professional and hardworking individuals who can work under any circumstances. There was no variation to the works.”

Cirus Rehman — Finance Director, Grosvenor Street, Mayfair

Read our reviews on Google ↗

Begin Your Garden Office

Book a no-obligation consultation at our Finchley Road design studio or in your home. The first meeting is free, lasts 60–90 minutes, and concludes with an honest indication of feasibility, programme and budget band. No salespeople. No pressure.

Call us020 8054 8756
Email uscontact@hampsteadrenovations.co.uk
Visit our studio250 Finchley Road, London NW3

Free Garden Office Consultation

Site visit · feasibility assessment · outline cost estimate · programme indication. No obligation. Saturday appointments available.

Enquire before 2pm — same-day call-back (Mon–Fri).

Sister CompanyHampstead Chartered Surveyors & Building Consultancy RICS-regulated surveying — independent advice250 Finchley Road, NW3