Garden Room

The Atelier

From£17,995Installed
Perfect For
  • Creative Studio
  • Yoga Room
  • Office
  • Lounge
Engineering
  • SIP Construction
  • 216mm Wall System
  • Ground Screw Foundations
  • 10 Year Structural Warranty
The Atelier
Configurator

Design Your Atelier.

Choose your size, doors, cladding, interior and extras. The price updates instantly — no commitment until you're ready.

Start Designing
  • Building Size
  • External Cladding
  • Door Style
  • Window Layout
  • Interior Finish
  • Flooring
  • Heating
  • Lighting
  • Decking
  • Pergola Options
Why Arden & Oak

Built like a home. Not a shed.

Stronger Construction

SIP panels — engineered to outperform stick-frame sheds.

Warmer All Year

216 mm insulation envelope rivals new-build homes.

Lower Running Costs

Heat retention up to 7× better than typical garden rooms.

Ground Screw Foundations

No concrete. Faster install, kinder to the garden.

Faster Installation

2–5 days on site once your build is delivered.

10 Year Warranty

Structural guarantee on every Arden & Oak build.

Wall Construction

See what makes an Arden & Oak different.

Every layer serves a purpose — strength, insulation, ventilation and durability.

Side-by-side wall cross-section: Arden & Oak 216 mm SIP build versus a typical 105 mm competitor wall
Arden & Oak
216mm
  • Structural SIP construction
  • 90 mm PIR insulated core
  • Ventilated rainscreen cavity
  • Service void for electrics
  • Year-round use
Typical Garden Room
105mm
  • Basic timber stud
  • 50 mm rockwool insulation
  • No service void
  • Minimal thermal performance
  • Seasonal use only
Like-for-Like Comparison

Over twice the wall thickness of most garden rooms.

The numbers behind why an Arden & Oak feels — and performs — like a home.

Specification
Arden & Oak
Typical Competitor
Wall Thickness
216 mm SIP
70–95 mm stud
Insulation
Full PIR core
Glass wool batt
U-Value
0.18 W/m²K
0.35 – 0.45 W/m²K
Structure
Engineered SIP
Timber stud frame
Ventilated Wall Construction
Yes — rainscreen
Rarely
Service Void for Electrics
Yes — 25 mm void
No
Interior Finish
Birch ply / plaster
OSB or melamine
Installation Time
2 – 5 days
1 – 3 weeks
Expected Lifespan
30+ years
15 – 20 years
Year-Round Use
Yes, all seasons
Spring – autumn only
Quick Specification

The headline numbers.

Structure
  • 216 mm SIP wall panels
  • Insulated roof & floor cassette
  • Structural Insulated Panel system
Insulation
  • PIR core throughout
  • U-value: 0.18 W/m²K
  • Triple-layer thermal envelope
Interior
  • 9 mm birch ply standard
  • Optional plaster & paint
  • Engineered oak flooring available
Doors & Windows
  • uPVC windows & doors as standard
  • Choice of 4 colour finishes
  • Argon-filled double glazing
Electrics
  • Full first-fix wiring
  • Consumer unit & RCD
  • LED downlights & sockets
Heating
  • Wall-mounted panel heater
  • Optional air conditioning
  • Underfloor heating available
Thinking about budget?

More ways to fund a garden room than you might think.

Most customers are surprised by the number of ways a garden room can be funded — from savings and personal loans to home equity and business funding. There may be options that suit your circumstances.

Explore funding options
  • Savings
  • Home equity
  • Business funding
  • Personal loans
Customer Reviews

Built to last. Loved by owners.

4.9
Overall Rating
120+
Projects Delivered
98%
Would Recommend
10 yr
Structural Warranty
“Better insulated than our extension. Use it year-round as a working office and weekend bar.”
Sarah & James M. · Exeter, Devon
“Quality is night-and-day above the brochure-built sheds we looked at. Arden's team had it weather-tight in 3 days.”
Daniel R. · Bath, Somerset
“Genuinely premium feel inside. Walls feel solid, finish is impeccable. Worth every penny.”
Priya & Tom K. · Stroud, Glos.
Process

From first call to finished room.

01
Design & Consultation

Site assessment, lifestyle brief, model selection.

02
Detailed Proposal & Fixed Quote

Itemised pricing, structural drawings and timeline.

03
Manufacturing & Preparation

Panels machined in the UK; ground screws set on site.

04
Installation & Handover

2–5 days on site, full clean-up and warranty pack.

More Information

Everything else. On-demand.

Open any section to dive deeper — construction, energy efficiency, payment schedule, FAQs and more.

Structural Insulated Panels (SIPs) sandwich a high-density PIR core between two engineered timber skins. The result is a wall system that's stronger, straighter and dramatically better insulated than traditional stud frames. Every Arden & Oak panel is precision-cut in the UK and delivered ready to assemble.

From outside in: ventilated cedar / larch rainscreen → breather membrane → 18mm OSB → 142mm PIR core → 18mm OSB → service void → 9mm birch ply (or plastered finish). Total wall thickness 216mm. U-value 0.18 W/m²K — beating current Part L building regs for new homes.

Independent thermal modelling shows our envelope retains heat up to 7× longer than a 70mm stud frame shed. A 1.5kW panel heater is typically enough for a 15m² office in mid-winter. Annual running cost for a year-round home office: ~£140 at 2026 electricity rates.

Standard finish is 9mm A-grade birch ply with a clear matt lacquer. Upgrades include plastered & painted walls (any Farrow & Ball or Little Greene shade), oak veneer panels, slatted acoustic walls and integrated joinery.

Survey & ground assessment (week 1) → ground screw foundations laid in a single day → panels arrive flat-packed → typical 4×3m build installed and weather-tight in 3 days → second-fix electrics, glazing and finishing over a further 2–4 days. No mess, no concrete, no skip.

10% deposit on order. 40% on factory production start. 40% on delivery to site. Final 10% on completion and snag sign-off. We don't broker finance — most customers fund their build through savings, a personal loan, home equity or business funding. See our funding guide at /funding-your-garden-room for a plain-English breakdown of each route.

Used wholly for business? Limited companies can claim Capital Allowances on the contents and services (electrics, heating, glazing) — typically 35–55% of the build cost. VAT is reclaimable. The structure itself remains personal asset, so no Capital Gains issue on house sale.

Do I need planning permission? — Most builds fall under Permitted Development (under 2.5m eaves, no closer than 2m to a boundary at full height). Can it run plumbing? — Yes, with mains feed from the house. Lead time? — 6–8 weeks from deposit to install.

We install across England and Wales. Standard delivery covers everywhere within 250 miles of our Devon workshop; further north (above Manchester) carries a £450 logistics supplement. Scotland and Northern Ireland by quotation.

Ready to create your space?

Whether it’s a home office, gym, studio or retreat, we’ll help design the perfect garden room for your lifestyle.

  • SIP Construction
  • 216mm Wall System
  • Ground Screw Foundations
  • 10 Year Structural Warranty

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