9 Chislehurst

Working with Holloway & Holloway Architects, the brief called for a bold, cubic new-build home that would hold its own architecturally while respecting the constraints of the site, and that would perform to full Passivhaus standard throughout airtight, low-energy, and built to thermal tolerances far tighter than standard new-build practice.

Performanceat a glance

●       Porotherm construction

●       Airsource heat pump (ASHP)

●       MVHR with cooling

●       Photovoltaic roof

●       Fabric U-values below 0.11 W/m²K (windows 0.8 W/m²K or below)

●       Airtightness achieved: 0.6 — the same benchmark Passivhaus certification itself requires

Every stage, from foundations to fit-out, was engineered as one system rather than aspecification checklist. The fabric itself was reworked to get there:

•     Thermalite → Porotherm block construction

•     Timber first floor → suspended concrete floor

•     Thermal bridges reviewed and eliminated

•     Marmox Thermo blocks at key structural junctions

•     Rigorous focus on airtightness throughout

The envelope combines Millboard cladding,Velfac windows and Schüco/Aluprof glazing into a single high-performance skin.

MARCH Design - Inside, our own joinery team took on the kitchen from design through to build together with the full-height sliding wall doors that let the ground floor open up or close down at will. All this without breaking the architects' clean lines. Bathrooms were finished to the same standard, working alongside great product manufactures suchs as Lusso Stone,Grohe, Duravit and Merlyn Showering.

•     0.6 air-tightness

•     EPC score of 111 — deep into the A band

•     EPC's own assessment shows no furtherimprovement available

The result performs like a certified Passivhaus home, without the certificate: proof that real performance and paperwork aren't the same thing. Another example of what March delivers when “good enough” isn't good enough.

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