Technical information

We pride ourselves on a highly efficient ARC building with low embodied carbon.

The table below gives technical performance indicators to show how our ARC buildings compare to standard or traditionally constructed buildings, as well as requirements for Passivhaus.


Current UK regulations

L1A & L2A 2013 (2016 amendments)

Passivhaus requirements Green Unit ARC
Floor insulation

0.25W/m²K (dwellings)

0.25W/m²K (non-dwellings)

<0.15W/m²K 0.184W/m²K
Wall insulation

0.30W/m²K (dwellings)

0.35W/m²K (non-dwellings)

<0.15W/m²K 0.167W/m²K
Roof insulation

0.20W/m²K (dwellings)

0.25W/m²K (non-dwellings)

<0.15W/m²K 0.167W/m²K

2.0W/m²K (dwellings)

2.2W/m²K (non-dwellings)


Fakro P5 – 0.5W/m²K

Glazed end units – 1.2W/m²K

Glazed doors

2.0W/m²K (dwellings)

2.2W/m²K (non-dwellings)

<0.8W/m²K Nordan doors – 1.2W/m²K
Air quality Medium High, filtered with MVHR High, filtered with MVHR

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

Contact us

Speak to the team

01865 682707

[email protected]

  • Please give us as much information as possible, where available: the number of units required; approximate size/usage of the units required; the location of site(s); whether you have already explored planning permission for your project; and whether you will need to raise finance for the project.
  • Would you like to receive quarterly updates on Green Unit's design and construction developments via email?