Technical Information
Dimensions of Green Unit ARC I and ARC II modular buildings
- Internal floor width 4.0m
- Internal height 2.4m at highest point
- Internal width 4.8m at widest point
- External footprint width 4.4m
- External width at widest point 5.4m
- External overall height 3.2m
- External height with floor at ground level 2.7m (foundation base 0.6m 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 0.6m below ground level)
Find out more about our offsite construction build process, and watch a timelapse of our ARC II for The Vindolanda Trust.
Materials used in design and build of ARC I and ARC II
- Spruce and birch plywood structure
- Wood fibre insulation
- Breathable cloth (external membrane)
- Airtight, vapour control (internal membrane)
- Triple glazed units
- High-performance airtight windows
- High-performance airtight exterior doors
- Internal cladding - painted 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
- Water and root-proof roofing membrane
Technical specification of the Green Unit ARC
|
Current UK regulations |
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 |
|
Ceiling 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 |
|
Air moisture content |
30% – 60% |
35% – 55% |
Below 40% |
45% – 50% |
|
Comfort temperature |
Not specified |
17⁰ – 20⁰ |
22⁰ |
17⁰ – 19⁰ |
|
Annual energy use per annum |
Not specified |
15kWh/m² |
200 kWh/m² |
15kWh/m² |
|
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 |