Straw bale: a personal journey
Straw bale: a personal journey
If the concept of a straw bale home conjures up images of a hobbit home in your mind, then this story may just change your perceptions. Builder Ken Longshaw has built a striking, comfortable family home from straw bale. Looking from the outside, you would never know this contemporary style home has walls made from rice husks and that’s exactly what Ken and his family intended.
From the warmth and quiet of his lounge room in the Southern Highlands, builder Ken Longshaw recalls the long hours of sitting in Sydney traffic day after day as time that could have been better spent with his family.
Almost two years ago, Ken and his young family made the decision to leave the hustle and intensity of city life far behind, making a tree change to the quiet village of Bundanoon – a new town, new home and new life.
Bundanoon was chosen for its beautiful location, and the fact that Ken and his wife Emily, loved the feel of the village and the local school. An open-minded community with an appreciation of green building sealed the deal, with Ken assured that there would be a keen interest in his eco friendly building business, ES Build, established 14 years ago.
Ken’s industry knowledge and research into building options meant the decision to build a straw bale home was a no-brainer. “We explored many options including mud brick but we knew the most important element of building a comfortable home here would be insulation and the thermal properties of straw bale are out of this world – nothing beats it,” he said.
“Also it is quite quick to build and lends itself to self-expression, an interpretation that can be personalised for each project and that appealed to us.”
The Longshaws wanted to build for the long-term, considering space needs now and with flexibility for change as the children grew up.
“I am appalled at the syndrome of project homes here in Australia where we build homes for 20-30 years livability or less. In Europe they design for 500 years. Ours is a short-term philosophy and it has implications for so many things – from energy consumption to space issues,” explained Ken.
“When I was working in construction in Europe, I saw a home being built from oak and at the same time they were planting oak trees so in 150 years they could replace some of the timber. That foresight is missing in Australia and those things inspired us when we planned our own home.”
Ken believes that when a home is planned for the long-term, the cost of living in the building over time becomes more important than the cost of the building itself. For example, if a family only plans to live in a place for five years, air conditioning may not be considered a large expense. Thirty years on, putting more thought into ventilation and insulation at the outset could have negated a significantly higher expense.
A home design was purchased from architect Peter Lees, an advocate of living in roof spaces to promote a sense of comfort and safety. The plan was then adapted for the block and family’s needs. Key features are two large water tanks under the living room, giving the home its thermal mass, and double-glazed windows to provide added insulation.
BUILDING BY HAND
The hands-on nature of straw bale building appealed to Ken. As a professional builder, he approached the project with a “get it right the first time” attitude and chose a post and beam structure for its sturdiness and longevity.
“Traditionally, straw bale homes are built with the roof sitting on top of the bales which makes them load bearing. I didn’t want to be coming back in two years to patch cracks from movement so went for a structurally sound post and beam construction where the straw bales fill the gaps between the posts rather than form part of the frame.”
Once the foundations were laid, water tanks installed and posts and beams in place, Ken called on friends and family to help with the rest - everything from tying and trimming bales to rendering. This practical support along with using straw bale for insulation and sourcing clay from the site resulted in significant cost savings compared with a standard building.
The entire family was involved with finishing the walls. The first layer of clay from the site was sprayed on then rubbed in by hand to seal the straw.
“It was tremendous fun. Our boys have had such a blast here. They already want to build homes of their own!”
The hands-on process also meant they were able to shape their building in a way that suited the preferred style.
“Many straw bale homes have round, continuous surfaces, hence the perception of straw bale homes being like hobbit homes. We decided we wanted sharp corners and could easily achieve that. With the interior clay walls, you can do amazing sculptural work if that’s what you desire. All the effects can be achieved without compromising the insulation or quality of the build.”
Lime render was used for the final exterior coat of the building with a combination of clay and lime on the inside to promote healthy indoor air. Clayset with carnauba wax was chosen for the lounge room walls, bringing texture and ambience.
“The flexibility, the colours you can achieve, that organic personal expression and the vibrance that you get out of a natural product like Clayset as opposed to paint, was ideal for our home.” said Ken.
ONE YEAR ON
Almost a year since the family moved into their new home, they are thrilled with the benefits that straw bale construction has brought.
“Not everyone was as convinced about the advantages of straw bale as I was,” Ken says as the sun blazes into his lounge room on a chilly four-degree day. “Now, everyone is ecstatic we did it. Our energy bill just came in – just over 10KW. That’s less than the average usage for a household of one person and we have five people here during the week and seven on weekends.”
The family is currently installing a 4kW power system and could easily go “off the grid” if desired.
Ken is also amazed at the indoor air quality, which he attributes to the fact the entire walling system of the home is vapour permeable – from the clay and lime interior walls, through the straw bales and exterior render to the outside.
“The walls breathe. Moisture generated inside through the use of the kettle, stove and bathroom is expressed outside. This natural transpiration of moisture keeps the house healthier and cooler on a humid day. Using clay on the interior walls also helps to suck in moisture and alleviate mould.”
Ken is still finishing the interior of the home, which will feature more Clayset walls, and a Marrakesh bathroom. We will be sure to share some images once the project is completed.
Looking back on those long days in city traffic, Ken is satisfied with his family’s choice. “It’s a beautiful home that costs next to nothing to heat and run. That translates to more time at home and more family time for us,” he said.