Bohdan Dorniak & Co. Pty. Ltd. » Hahndorf Strawbale House

Hahndorf Strawbale House

23/05/2019

Construction Phase 1: Site Excavation and Pouring the Slab
The building slab, constructed in November 2018, was engineered to be raised above the ground using waffle pod footings. Infrastructure for the strawbale wall construction was also installed in the slab through tubes on the slab edge which tie downs feed through to support the strawbale walls. Waterproofing and plumbing services, including a set down to the bathroom was also constructed during this phase.

Following construction of the slab, the timber frame was constructed in February 2019. This included the timber trusses of the roof form, internal stud timber walls, as well as the structural timber of the external strawbale walls.

(above) This image is looking out to the central courtyard of the house.

Construction Phase 3: Roof construction
Before strawbale construction begins, the roof is installed to protect the strawbale from weather conditions. Roof installation includes the fitting of gutters, flashing, roof capping, and the connection of plumbing (downpipes etc). This took place in late March.

(above) Birds eye view of the roof form taking shape!

Construction Phase 4: Strawbale
At the beginning of April, construction of the strawbale walls began. The first part of construction involves the construction of strawbale up stands on which the bales will sit (above).

Following this, strawbales are fit into place as per the design, which considers the dimensions of each bale for walls, and opening sizes etc. They are then tied down and compressed with straps which feed through the black tubes installed in the concrete slab. Strawbale walls are braced, compressed and compacted during this phase in preparation for the first coat of render.

Strawbale walls take three coats of render (approx 40mm thick). The process of rendering requires a tailored skill set and employs specialized techniques to ensure a prime finish, and sufficient strength/durability.

PROJECT DETAILS

Location: Hahndorf
Construction timeline: Nov 2018 – September 2019

ARCHITECTURAL BRIEF

Hanhdorf Strawbale House was conceptualized in early 2017. It is an example of an energy efficient design harnessing the strengths of strawbale as a sustainable construction material in a contemporary architectural design. The footprint and form of the house is defined by and responds to the context of the site through consideration of existing structures, plantings, as well as the natural slope of the site, privacy, and desired views. The most critical considerations of the design were made with regard to its sustainability and energy efficiency. This includes consideration of orientation, building materials, and solar loads, which were tailored to existing local climatic conditions such as rain, wind, temperatures, etc.

The design integrates a central outdoor courtyard that acts as an anchor point between two wings of the house. The North-West wing includes an open plan dining/living space and study nook, whilst the South-East wing includes bedrooms and a central bathroom. Strawbale construction is used as the external walls of the bedroom wing, providing thermal comfort by optimizing its thermal insulation properties. In the living/dining space, a stone fireplace was integrated on the (W) wall which is also strawbale.