Healthy Buildings: Hempcrete and materials for a healthy home – Michael Leung, Balanced Earth Architects

Prioritising health when selecting materials and products is simply common sense, and the best thing about healthy materials – they are also brilliant for the environment.

In today’s episode we move on to our next sustainable design theme – healthy buildings.

We’ll investigate the design of a house on an off grid site located in Mullumbimby in the Subtropical northern New South Wales hinterland. I talk with architect, Michael Leung, the director of Balanced Earth Architects, who will share the inside story on his Sky Farm project.

Today we’ll learn about:

• The key design considerations, materials and products for a healthy home,
• We talk further about the process, costs and benefits of using hempcrete in custom architectural construction, and
• We’ll also cover a wealth of other insights and practical information drawn from Michael’s extensive experience as both an architect and a builder.

Australian Architects can claim formal CPD hours for these podcasts.

MORE INFORMATION

Find everything you need on the Renovation Collaborative website.

www.renovationcollaborative.com.au

• PODCASTKey points summary, timestamps and resource links
• FREERESOURCESTranscript edited into clear Q&A.
• CPDAustralian architects can find more information on CPD, and
• COURSESEleven easy to read courses demystifying the entire home design and construction process.

KEY POINTS SUMMARY

1. Healthy building is about interrogating the detail of materials. Often that's not presented on websites and you have to dig deeper into the Material Safety Data sheets.

After extensive research, Balanced Earth Architects now work with a simple palate of materials and the basics include: hempcrete, recycled timber and other materials from demolition, galvanised steel, timber windows, and natural finishes including clay and lime renders.

2. A hempcrete and lime rendered wall composition prevents mould growth. Hempcrete is vapour permeable, allowing moisture to travel from the inside to outside. In addition, lime render has an alkali surface preventing mould growth.

3. A hempcrete wall is set up as follows:

• It can be constructed on a timber framed or concrete floor.
• In timber framed construction, the joists or bearers may be doubled up to carry more load when the hemp is wet. Then a 10 or 20mm compressed FC board is fixed on top as a base for the hempcrete.
• To build the wall, a timber stud frame is setout 80mm in from the external wall line. The 90x45 stud sits centrally in the 250mm hempcrete wall, allowing 80mm of cover on both inside and outside.
• The entire house is constructed with standard timber stud frame construction. All timber can be untreated pine because the lime in the hempcrete protects the timber, and
• The services are clipped into the stud wall, and...