Architecturally beautiful, high performing eco homes, annexes and holiday lets

Green Unit’s beautiful, craftsman-built ARC homes are for people looking to reduce their carbon footprint and save money on heating bills, without compromising on beauty or comfort. These stunning carbon neutral buildings blend in with the natural environment outside, and offer inspiring, deceptively spacious, light-filled interiors.

Bespoke, cost-effective green buildings for almost any site

Do you want to design your own layout? Does your site make traditional building difficult? Are you looking to move quickly?

ARCs are built from prefabricated modules to create the perfect solution for your needs. You decide the size and layout of the rooms, choosing from the range of finish and window options. We can also supply hand-crafted built-in furniture and bespoke pieces. (See the ‘Options’ section, below). Later you can extend your ARC by adding extra sections.

ARCs require minimal foundations and can be erected almost anywhere in days. They can be built on existing concrete, hillsides, flat roofs and above-ground platforms – even on stilts. They comply with all building regulations, and the low-rise design and excellent energy performance make them attractive to planners.

Bespoke furniture

Create a beautiful, spacious feel with built-in beds, wardrobes, tables and sideboards, hand crafted in Oxfordshire by our in-house cabinetmakers.


  • Quick and inexpensive to erect – minimal foundations needed
  • Low running costs – high performance insulation means you’ll hardly ever need to use the heating
  • Bespoke modular sections let you create the perfect home for your needs
  • Easy to extend as you need more space – simply add new modules
  • Long lifetime – engineered to offer exceptionally robust building performance
  • Year-round comfort – warm in winter, cool in summer and healthy air all year round, with climate control, air heat exchanger, triple glazing and air-filtering system
  • Ventilation system offers pollen-free fresh air and helps avoid condensation
  • Planning-friendly – classified as a relocatable temporary structure
  • Large end windows for light-filled rooms-with-a-view
  • Soundproofed walls create privacy
  • Off-grid renewable energy system available as an upgrade


  Green Unit buildings Traditional buildings
Planning permission Classed as permanent or temporary where permanent planning consent is impossible Full planning consent usually required for permanent buildings
Foundation type Lightweight building on helical piles requires minimal ground preparation and disruption Soil removal, engineering and concrete pour usually costly, time consuming and disruptive
Speed of installation Pre-made, pre plumbed, buildings are quick to install with no cost escalation Lengthy preparation, first , second and finish fixing stages with cost escalation risk
Energy performance Highly insulated, climate controlled with air heat exchanger and triple glazing At risk of energy loss by air leakage and cold-bridging through walls and widows
Sustainability Timber construction, sheep’s wool and green roof produce negative carbon footprint Materials and production processes require heat energy, heavy transport, produce CO2
Design configuration and reconfiguration Modular design allows unique individual configuration and low-cost reconfiguration choices Bespoke design and reconfiguration time-consuming and costly
Cost Pre-manufacture fixes total building cost to between £1K and £2K per square metre Final costs of traditional buildings often rise to £2K - £3K per square metre

Configuration options

Length options

• 1 bedroom
• 2 bedroom
• 3 bedroom
• 4 bedroom

Entry door options

• French doors to side of building
• French doors to front of building
• French doors to rear of building
• Single door to rear of building
• Combination of end and side doors

Window options

• Front/rear feature window
• Roof window
• Wall window
• Mansard window (combined roof and wall windows)

Room options

• Kitchen
• Bathroom
• Additional bathroom
• Store room

Layout options

• Straight
• T-shaped
• Double barrelled
• H-shaped
• Complex of multiple buildings

Furniture options

• Built-in sideboards
• Built-in tables and benches
• Built-in box beds
• Wardrobes and storage systems

External finishes

• Lime render
• Red cedar cladding 
• Decking in a range of dimensions

Internal finishes

• Varnished or painted pine walls
• Fabric-covered dividing walls
• Flooring in rustic oak, white oak, dark walnut, tile, vinyl or carpet
• Solid panel door in oiled oak or limed oak
• Frosted or clear glass panelled door

Price Guide

Please email This email address is being protected from spambots. You need JavaScript enabled to view it. for current pricing guidelines.