Airtightness work done result below.

The mean n50 for this building is 0.555ac/h:

The n50 is how the air permeability rate is expressed in air changes per hour (ac/h)

20/20 Installing large double glazed panel 3.0m high x 2.5m wide in ‘Reynaers’ CP150 thermally broken aluminium system.

Breathable 150mm spray foam insulation, around steel, between rafters & around steel thermal breaks.

Roof Insulation 120mm ‘Xtratherm’ foil backed PIR, with concealed eaves box gutter.

Ground floor with 150mm ‘Kingspan’ PIR foil backed insulation, with heat recovery ventilation ducts, and underfloor heating.

Upper level steel frame erected. Thermal breaks to outriggers for overhang to reduce summer heat load.

Upper level concrete floor slab with ‘Schok Isokorb’ thermal break at overhang.

Fibre glass wall ties to reduce thermal bridging, with 120mm ‘Kingspan’ PIR foil backed insulation & 50mm cavity.

Thermal blocks in deadworks, 4 courses to reduce thermal bridging, soon to be wrapped in radon barrier to further improve performance.

All dug out with big pile of dirt, for the future terrace.