Straw bale passive house in Wels / Upper Austria

Written by Herbert Gruber

The bales are installed vertically between the transoms. The bales were installed in the horizontal wall before the second planking was installed. For narrower compartments, the bales were cut with a band saw.

Key data

Province:Upper AustriaCity:WelsCompletion:2005Type of Construction:infill constructionDesign/ArchitectureDI Rupert PuntigamCarpenter:Zimmerei SöllradlStraw Builder:DI Rupert PuntigamPossibility to visit:NoPress photos:No
Photocredit:DI Rupert Puntigam
Residential acreage:462m2Heating demand:16U-Value (Wall):0,12W/m2KU-Value (Roof):0,12W/m2KHeating/Ventilation System:Ventilation Compact unit, 2 units KWL by Paul with heat recovery and brine EHE. Heating Heat source: exhaust air, ground, biomass Heat generation: Heat pump, boiler in living room (water-bearing) Solar energy use: Therm. Collector supply air, heating surface water-bearingCategories:Infill Construction, Passive House, Projects Austria, Projects-Technique,
More about this Straw Bale House

The wall construction (from the outside to the inside):

  1. ground floor: Heraklith pre-assembled for plastering with underlying foil between straw and Heraklith (low sd-value – formwork sheet).
    Upper floor: MDF board 16mm clad with larch boarding
  2. transom with straw filling 38cm
  3. OSB 18mm as vapour barrier; 50mm Heraklith installed and plastered with pure slaked lime plaster by the owner
  4. New straw bale insulation method: Bales are installed vertically between transoms whose distances are matched to the dimensions of the straw bales. The installation was carried out with the wall lying down before the installation of the 2nd planking. For narrower compartments, the bales were cut with a band saw.

Der Wandaufbau (von außen nach innen):
1. Erdgeschoß: Heraklith vormontiert zum Verputzen mit darunterliegender Folie zwischen Stroh und Heraklith (niedriger sd-Wert – Schalungsbahn)
Obergeschoß: MDF-Platte 16mm mit Lärchenschalung verkleidet
2. Riegel mit Strohfüllung 38cm
3. OSB 18mm als Dampfsperre
4. Heraklith 50mm in Eigenregie montiert und mit reinem Löschkalkputz verputzt
Neue Strohballendämmweise: Ballen sind stehend zwischen Riegel, deren Abstände auf das Strohballenmaß abgestimmt sind eingebaut. Der Einbau erfolgte bei liegender Wand vor der Montage der 2ten Beplankung. Für schmälere Fächer wurden die Ballen mit einer Bandsäge zugeschnitten.

About the author

Herbert Gruber

Herbert is author of the book "Neues Bauen mit Stroh in Europa" (New Building with Straw in Europe), head of the austrian strawbale network ASBN and partner in the Leonardo-project "STEP" (Strawbale Training for European Professionals) and the Erasmus project "BuildStraw Pro" (a project to get formal national recognition of the training) and "Make your City Smart". As a collector he documents European straw bale buildings since 1999 on his website (database, german), in lectures, workshops and books.