Technical Information

• Internal floor width 4.0m
• Internal height 2.4m at highest point
• Internal width 4.8m at widest point
• External footprint width 4.5m
• External width at widest point 5.4m
• External overall height 3.2m
• External height with floor at ground level 2.7m (foundation base 0.5m below ground level) 

ARC II 

• Internal floor width 6.4m
• Internal height 2.4m at highest point
• Internal width 7.2m at widest point
• External footprint width 6.6m
• External width at widest point 7.8m
• External overall height 3.2m
• External height with floor at ground level 2.7m (foundation base 0.5m below ground level) 

Find out more about our offsite construction build process, and watch a timelapse of our ARC II for The Vindolanda Trust. 

• Spruce and birch plywood structure
• Wood fibre insulation
• Breathable external membrane
• Airtight, vapour control (internal membrane) with fully taped joints
• Triple glazed units
• High-performance airtight triple glazed windows (vented or unvented, as required)
• High-performance airtight triple glazed exterior doors (vented or unvented, as required)
• Internal cladding - painted solid timber (other options available, to be determined during design consultation) 
• External cladding - thermally modified, sustainable UK poplar (other options available, to be determined during design consultation) 
• Water-based acrylic paints and lacquers
• Solvent-free adhesives
• Powder-coated aluminium cladding and window flashings
• Painted timber end fascia boards
• Water and root-proof roofing membrane
• Sedum green roof

Technical specification of the Green Unit ARC 

	Current UK regulations (for non-dwellings)	Passivhaus requirements	Standard building	Green Unit
Floor insulation	0.25W/m²K	<0.15W/m²K	0.22W/m²K	0.18W/m²K
Wall insulation	0.35W/m²K	0.15W/m²K	0.3W/m²K	0.16W/m²K
Roof insulation	0.25W/m²K	0.12W/m²K	0.24W/m²K	0.16W/m²K
Airtightness	10m³/hr/m²	0.6m³/hr/m²	10+ m³/hr/m²	2m³/hr/m²
Air changes per hour	10ach	0.6ach	7ach	variable to 10ach
Air quality	Medium	High, filtered	Medium	High, filtered
Embodied energy	Not measured	Minimum possible	129 – 239 kW/m²	81 kW/m²
Recyclability	No requirement	Encouraged	Low recyclability	Fully recyclable
Testing procedure	SAP	Physical test	SAP	Physical test

 

- See further information including information about U Values in Building Regulations Part L2A (non dwellings) on the Planning Portal (external link).

- See further information about Passivhaus requirements (external link).