This week’s PHBdW features a passivhaus warehouse of sorts, by Architects Collective. The Obst-bau Leeb is located in Sankt Andrä am on Zicksee, along the easternmost Bundesland of Austria. It is an apple processing and storage facility with an attached sales and administration building, the latter being the passivhaus element of the project.
The clients were motivated to make the building as green as possible, utilizing recycled or re-used materials for interior lighting and casework, and lower-embodied energy materials to minimize the facility’s footprint. The building utilizes prefabricated wood panels that were installed in a few weeks. Total construction took less than six months.
The prefabricated panels are somewhat similar to SIPs, with OSB on the interior (presumably the air barrier), 16” TJIs with cellulose insulation and a fiberboard exterior. A rear ventilated OSB rain screen uses different stains to add a touch of frivolity to the hyper minimal facade. The roof is constructed of the same panels, and a suspended ceiling (thankfully, not ACT) allows for recessed lighting that doesn’t penetrate the air barrier. This is critical in achieving the passivhaus airtightness requirements.
The floor is a 4″ concrete slab over 10” of insulation. We still struggle with these amounts of foam insulation, but after completing the Passivhaus Consultant training and tooling around with PHPP, understand the reasoning behind it.
Ventilation is supplied through a Drexel und Weiss aerosmart mono, a highly efficient compact HRV with heat pump for space heating. Large operable screens finished with adverts provide shading from excessive solar gain in summer. We’re also really impressed with the large lift-slide doors – any thoughts as to who manufacturs a passivhaus certified hebe-schiebetuer?
- Walls: U-value=0.10 W/m²K (R-57)
- Roof: U-value=0.10 W/m²K (R-57)
- Floor (slab): U-value=0.11 W/m²K (R-51)
- Windows: U-value=0.75 W/m²K (R-7.5), SHGC (G-wert) =0.52
- Airtightness: 0.26 ACH50 (this is ridiculously tight)
- Heating Demand: 16.1W/m²K/a (5.10kBTU/ft²/a)
This small project is a success on many levels. It’s definitely inspiring to see a firm pushing the aesthetics and energy efficiency of a simple industrial facility. We are looking forward to architects and clients on this side pushing the highly efficient, well designed envelope as well.
- Architect: Architects Collective ZT, Wien (AT)
- panel fabricator: Weissenseer Holz-System-Bau
- Mechanical: Gangl Haustechnik
- Product Design: Gabarage Upcycling Design
- Location: St. Andrä am Zicksee (AT)
- GFA: 400 sm (4,305 sf)
- building costs: 1000€/m² ($130/ft²)
- completed: 2009