PHBdW: Passivhaus Bau der Woche 01

Brute Force has slowly been forming a list of projects that will form the basis for a weekly series highlighting modern passivhaus buildings. These buildings stand out amongst the superinsulated boxes that, for now, typify the genre. This series will highlight houses, but will also explore multifamily, commercial, educational and institutional facilities. Considered yourself warned…

For the inaugural PHBdW post, we wanted to focus on a project by an up and coming Swiss firm that has recently completed two projects that qualify for Minergie-P. Minergie (minimal energie) is a Swiss low-energy standard that seems to hold more promise than LEED, but isn’t quite as stringent as passivhaus. Minergie-P was introduced to align with passivhaus, except the Minergie area calculations are gross instead of net floor area. There are some additional differences, which can be explored here (PDF)

This last weekend at the 14th International Passivhaus Conference in Dresden, Halle 58 Architekten’s three family apartment complex in the outskirts of Bern took first prize for the 2010 passivhaus architekturpreis. This project blew away the competition.

The complex is three relatively open apartments built where garages for adjacent buildings formerly stood. Peter Schürch, principle of Halle 58,  built this for his family and two others, and a lot of emphasis was placed on making it as green as possible.  Locally sourced wood was selected as the primary construction material above grade.  Materials were selected based on embodied energy, durability and reduction of harmful chemicals. Wooden blinds offer protection from heat gain in the summer, especially needed due to the abnormally high percentage of glazing for a passivhaus.

Exterior walls are clad with prefabricated cement-wood panels. The structural members are a prefab system manufactured by Lignotrend that is basically a Modified Larsen Truss. The 30cm cavity is filled with cellulose, and an OSB air barrier separates an additional 3″ of rigid mineral wool to eliminate thermal bridges.

The green roof can be used as a terrace, and incorporates solar collectors which supply most of the domestic hot water. Area was carved out for future photovoltaic installation. To further enhance the usability of the building, Schürch provided space in the unheated entry and stairwell for a future elevator. We’re also really enamored with the generous terraces to the south, a rarity in several multifamily projects here in Seattle.

Walls: U-value=0.11 W/m²K (R-52)

Roof: U-value=0.11 W/m²K (R-52)

Floor (at unheated basement): U-value=0.10 W/m²K (R-57)

Windows: U-value=0.92 W/m²K (R-6)

Heating Demand: 13.3W/m²K/a (4.21kBTU/ft²/a) calculated, actual is lower

Ubergreen, open plan, lots of natural light and transparency… Suffice to say, we’re really impressed with this project and definitely see this raising the bar for multifamily passivhaus projects worldwide.

  • Architect: Halle 58 Architeken, Bern (CH)
  • Engineer: Tschopp + Kohler
  • Mechanical:  Riedo Clima
  • Location: Liebefeld (CH)
  • GFA: 739 sm (7,950 sf)
  • completed: 2006

Further Reading

  • Halle 58 has several publication links from their website.
  • Minergie writeup on the Liebefeld residences.
  • Detail mag with more details and diagrams (PDF)

One response to “PHBdW: Passivhaus Bau der Woche 01

  1. namhenderson