Gale & Snowden Architects have recently finished a 2 year building performance evaluation monitoring exercise at our Passivhaus scheme Knights Place. With funding from the Technology Strategy Board (TSB) we were fortunate enough to carry out, in quite some detail, extensive monitoring of the Passivhaus social housing scheme that we designed almost 5 years ago. This in-depth study has taught us a lot, and we can now confidently say from this level of feedback what does and does not work with a Passivhaus design.
The monitoring comprised two distinct elements: hard monitoring which records the facts in an objective manner with the use of sensors and equipment, and soft monitoring which involves quality checks of installations and discussions and interviews with tenants and the design team.

Hard Monitoring

  • Main metering and sub metering – heating, lighting, DHW, cooking, ventilation and appliances.
  • Solar thermal system performance monitoring.
  • Performance monitoring of MVHR systems – air flow tests & energy consumption assessment. In addition to the mandatory TSB tests, measurements of temperature and humidity in all four air streams of the ductwork were taken, as well as an additional measurement after the heater battery in the supply air. This provided details of heat exchanger efficiencies at different operating temperatures.
  • Internal comfort monitoring – temperature and humidity monitoring in kitchens, living rooms and main bedrooms. CO2 monitoring in living rooms and main bedrooms.
  • External temperature and relative humidity monitoring.
  • Air permeability and tracer gas tests in accordance with ATTMA: two tests over two winters.
  • Summer time temperature and comfort monitoring to determine comfort conditions during hot periods, and to see how well the mass and super insulated approach performs. This study is beyond the TSB mandatory requirement.
  • In-situ U-value thermal resistance monitoring of wall construction details using heat flux sensor method and data logger.
  • Infrared thermography survey of the three flats and key thermal elements.

Soft Monitoring

  • Design and construction audit.
  • Design team review of SAP/PHPP and design details & commissioning data for services.
  • Installation check of services & fittings by the team.
  • Building user survey (BUS) questionnaire to all eighteen flats.
  • Interviews and walkthroughs with occupants to determine controls issues, modes of operation, different lifestyle habits, ease of use, fine tuning of energy systems, user guide.
  • Energy audits using DomEARM methodology (domestic energy and reporting method).

The full report can be viewed here.