U values compared W/(m²K)
| Element |
UK Building Regs for new elements |
Passiv Haus |
| Wall | 0.28 | 0.15 |
| Pitched roof insulation at ceiling | 0.16 | 0.15 |
| Pitched roof - insulation at rafter level | 0.18 | 0.15 |
| Floors | 0.22 | 0.15 |
| Windows | 0.80 | |
| Element | Threshold U Value | Improved U value |
| Wall - Cavity insulation | 0.70 | 0.55 |
| Wall - External or internal insulation | 0.70 | 0.30 |
| Floor | 0.70 | 0.25 |
| Pitched roof - insulation at ceiling level | 0.35 | 0.16 |
| Pitched roof - insulation between rafters | 0.35 | 0.18 |
| Flat roof | 0.35 | 0.18 |
