6 Stewart Road, Harpenden — Passivhaus New Dwelling
Passivhaus new-build of 370 sqm over ground and two upper storeys, built from Porotherm engineered clay masonry for fast, dry, lightweight construction without steels. Thermal bridging and airtightness were detailed to the Passivhaus limit of 0.6 ach @ 50Pa, with MVHR and air-conditioning throughout.
- Location
- Harpenden, Hertfordshire
- Floor area
- 370 sqm
- Storeys
- 3
- Standard
- Passivhaus
- Airtightness
- 0.6 ach @ 50Pa
- Systems
- UFH, MVHR, split AC
A new three-storey, 370 sqm Passivhaus dwelling at 6 Stewart Road in Harpenden, built over ground and two upper storeys. The design follows Passivhaus principles, using Porotherm engineered clay masonry for fast, dry, lightweight construction without steels. Extra care was taken with the thermal-bridging and airtightness details to achieve 0.6 ach @ 50Pa — the Passivhaus airtightness limit — and products were selected to meet their published U-values.
The drawing set
Issued between 2022 and 2023, the package covers ground and first-floor plans, elevations, three section sheets and twenty-six junction details — garage and entrance doors, sliding doors, windows, roof-lights, cathedral and flat-roof abutments and the foundation detail with air brick. A compiled 32-page as-built set closed the project out.
Services
The house has mechanical ventilation and air-conditioning, with underfloor heating and plumbing on each floor.
SOFTWARE / WORKFLOW
- Autodesk Revit
- AutoCAD