Built in modules.
Finished like a house.

The design build-up

Walls

U 0,140 W/m²K

Roof

U 0,135 W/m²K

Floor

U 0,145 W/m²K

Insulation

graphite EPS, λ 0,030

Windows

triple glazing, Uw ≈ 0,8

Module height

3,45 m

How the band is worked out

1. Average of the three opaque elements: (0,140 + 0,135 + 0,145) ÷ 3 = 0,140 W/m²K. That is the figure on the ladder, and it falls in the top band, ≤ 0,15.
2. The worst single element is the floor, 0,145 W/m²K. On its own it still sits inside that band, so the class does not depend on which element you look at.
3. Check the wall against its own materials: U 0,140 means R = 1 ÷ 0,140 = 7,14 m²K/W. The 200 mm graphite EPS core alone gives 0,200 ÷ 0,030 = 6,67 m²K/W; the two OSB 12 skins, the linings and the surface films make up the remaining 0,47.
4. Spread across the envelope: 0,145 − 0,135 = 0,010 W/m²K between the best and the worst element. There is no cold side to the house.
5. The glazing is the one place heat leaves faster: at Uw ≈ 0,8 it loses 0,8 ÷ 0,140 = 5,7 times what a square metre of wall loses. That is why it is triple and not double.

Read this as design values, not as a certificate. Everything above is calculated from the design build-up — not an issued energy performance certificate. Nobody has measured this house. The bands are our own reading scale for the average U-value of the opaque envelope, with each range printed beside it; they are not a legal energy class. A certificate is issued for one building on one plot by an authorised auditor, who weighs orientation, shading, services and the way the house is actually lived in. When your TUNDRA stands, that is who signs it.

We have not printed a comparison against a legal minimum U-value, because we only publish a normative figure we can cite exactly. The comparison above is the house measured against itself.