A guide to garden rooms.
A considered overview of planning, design and construction — everything you need to know before starting your project.
Planning & Regulations
Most projects fall under permitted development — but every site has its quiet rules. We guide you through them so the building feels effortless from the first sketch.
In most cases, no. Garden rooms typically fall under permitted development if they sit beneath the height limits, take less than half the garden, and are used as ancillary living space. Where your site is more sensitive, we apply on your behalf.
Yes — though permitted development rights are often restricted in these settings. Our team will advise on the best approach for your site and, where required, prepare and submit a sympathetic application.
Within two metres of a boundary, height is limited to 2.5m at the eaves. Beyond two metres, taller forms become possible. We design around your boundary lines so the room sits quietly within the rules.
Outbuildings used as primary sleeping accommodation usually require formal planning permission and Building Regulations sign-off. We guide you through this during your consultation, and design accordingly if a true annexe is the brief.
Design & Architecture
Every commission begins with a conversation about how the room should sit in the garden — its proportion, its materials, and the way it ages.
Our collection is a starting point, not a catalogue. Footprint, proportion, glazing, cladding and interior finish are all considered against your site, your home and the way you intend to use the room.
Western red cedar, thermally-modified ash, charred timber, oak and Accoya — alongside a quieter range of composite slatted finishes for low-maintenance schemes. Every option is shown as physical samples before specification is signed off.
Yes. uPVC double-glazed doors and windows are standard and discreetly detailed. Slimline aluminium is available as a considered upgrade. Configurations follow the architecture of your home.
We take cues from your home — its materials, rhythm and palette — and translate them into the garden room without imitation. The result feels related, not duplicated.
Build & Installation
On-site weeks are short. Most of the craft happens beforehand, in our workshop, so your garden remains undisturbed for as little time as possible.
Our installation service includes the foundations, building structure, external cladding, roof system, doors, windows, insulation, internal finish and flooring as specified in your quotation. External utility connections — including final electrical connection, water supplies, drainage and internet services — are typically arranged separately by local contractors due to the site-specific nature of these works.
Typical builds complete in 5–10 working days on site, once foundations are set. Larger or more complex commissions extend gently. You receive a full programme before the team arrives.
Most projects use ground-screw foundations — quiet, fast, and kind to root systems. Where the site asks for it, we design a poured concrete base or a steel-framed deck.
Yes. Foundations, levelling and any required preparation works are handled in-house. Where heavy access works are needed, we coordinate them as part of the same programme.
Generally, no. Water and drainage connections are highly site-specific and are usually best completed by a local qualified plumber or groundworks contractor familiar with your local regulations and underground services. For this reason, we do not typically include water or drainage connections within our standard installation package. We can however design the building to accommodate future connections and provide guidance on any requirements during the planning stage — often the most practical and cost-effective approach for our clients.
Ideally a clear path of around 800mm. Many of our projects sit behind narrow side returns — our build method is designed around tight access. Our team will survey your site before quoting.
Performance & Insulation
Year-round usability is the brief. Wall, floor and roof build-ups are specified to perform quietly through a British winter and to remain cool in summer.
Yes. Our standard build is comfortable to occupy in deep winter using a low-output electric heater or panel radiator. Many clients find no additional heating is required during the working day.
Walls, floor and roof are insulated to current new-build standards. Cold bridging is detailed out at junctions, and a continuous vapour control layer keeps the building dry through seasons.
A composite of rigid PIR and mineral wool — chosen for thermal performance, acoustic damping and longevity. Lower-embodied-carbon options are available on request.
Typical U-values: walls 0.18 W/m²K · roof 0.15 W/m²K · floor 0.18 W/m²K. Glazing is 1.2 W/m²K as standard, with a slimline aluminium upgrade taking it lower.
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Begin your project →Electrics & Options
First-fix is included in every commission. Beyond that, you choose how the building is wired — quietly, like the rest of the room.
Yes. First-fix wiring, internal sockets, switches, downlights, an external feature light and a dedicated consumer unit are all included. The internal wiring is left ready for a qualified electrician to make the final connection to your home.
In most cases, no. We prepare the building for electrical connection and can install internal wiring and accessories where specified, but the final connection to your home's electrical supply is typically carried out by a local qualified electrician. For projects within approximately 50 miles of our Devon workshop, we may be able to assist with the connection directly. Beyond this distance, it is usually more cost-effective to use a trusted local electrician — and we are happy to liaise with them and provide any information they require.
Yes — wall-mounted electric panel heaters, infrared panels, or a discreet heat-pump unit can all be specified. We recommend the right approach based on your usage and footprint.
Most clients reach the building with a mesh node or a Cat6 trench-laid back to the house. We coordinate the route and conduit during groundworks so the cable runs are invisible.
Yes. Skylights, deep eaves, integrated planters, hidden gutters, garden-side overhangs and pergola extensions are all part of the design vocabulary. We discuss them at concept stage.
Pricing & Process
We are direct about cost. Quotations include the things that quietly make a building good, rather than holding them back as upgrades.
Typical projects sit between £28,000 and £75,000 fully fitted. Outdoor-series compact units begin at £15,000. Final figures depend on size, glazing, cladding, access and chosen interior finish.
Foundations, weatherproof shell, insulation, glazing, cladding, internal finish, first-fix electrics, lighting, delivery and installation. Soft furnishing and final electrical connection are excluded.
Yes — every project begins with a design consultation, either at our studio or at your home. Concept sketches and an indicative cost band follow within ten working days.
A staged payment programme keeps things calm: deposit on order, balance on workshop completion, final payment on site handover. The full schedule is shared with your quotation.
If your garden room is used for business purposes, you may be able to claim tax relief on certain costs associated with running your workspace. Common examples include office furniture, computers and equipment, heating and electricity, broadband and communications, insurance costs and, in some cases, part of the building cost itself. The amount you can claim depends on whether you are self-employed, operate through a limited company, and whether the building is used exclusively for business purposes. Because every situation is different, Arden & Oak always recommends seeking advice from a qualified accountant before relying on any tax benefits.
Many limited company owners choose to purchase a garden office through their business. Depending on how the building is used, there may be opportunities to offset certain costs against business income. As tax rules vary and personal use can affect eligibility, professional accounting advice should always be obtained before purchase.
Aftercare & Longevity
A well-built room asks little of you. We design for a long, quiet life — and we stay in touch long after handover.
Built well and maintained sensibly, our garden rooms have a design life of 50 years or more. Cladding will weather; the building beneath will not.
Annually, gutters cleared and cladding inspected. Every two to three years, an oil refresh on natural timber finishes if you wish to preserve their original tone.
Yes. A 10-year structural warranty as standard, alongside manufacturer warranties on glazing, cladding and electrical components.
Considered, well-detailed garden rooms reliably add value — typically 1.5 to 2× their build cost when sympathetic to the home. We design with that quiet uplift in mind.
Ready to start planning your garden room?
Book a design consultation and begin shaping a space designed around your home, lifestyle and garden.