Bush Retreat Uses Steel To Overcome Site Challenges

Architect Michael Marshman has designed a striking bush retreat for a challenging isolated site on the NSW far south coast.

The difficult site brought up several issues to be considered during the design, including being within bushfire and termite zones and having little suitable access for heavy loads of building materials.

Michael turned to steel for a solution to all of these issues. "The building site is on a timbered property without any services, adjoining a national park and forestry land," he said. "The owners wanted a local architect to design a two bedroom retreat which could be used as a base for hiking and exploring the bush, but beyond that a lot of the design process was about what they needed in that location rather than what they wanted."

As a result, roofing and walling made from ZINCALUME® steel was chosen for the house as it is bushfire and termite proof and lightweight enough to be transported easily to the site. By using steel, Michael could also ensure that the house would 'touch the earth lightly', leaving as minimal a footprint as possible on the land.

The choice of a steel post and beam frame also meant that builder Robert van der Platt of Trinder Alpine Constructions could fabricate components offsite, break them down for shipping to site then reassemble them.

As soon as the frame was in place, the roof went on and was temporarily plumbed to a large tank on top of the house so that water was available on site for the remaining building operations. The cleverness of the roof design lies in its butterfly shape with 18 degree pitches which allow rain to drain to valleys which feed just two large rainheads, without the need for the guttering.

The roof, made from ZINCALUME® steel in the profile LYSAGHT KLIP-LOK 700 HI-STRENGTH®, is more often seen on large commercial or industrial sites where its conceal fix clip system is highly regarded for its ability to provide large areas unbroken by rows of fixing screws.

"We selected KLIP-LOK 700 HI-STRENGTH® profile because of the rain carrying capacity of its wide flat pans," Michael said. "The wide flat pans between the ribs give a good initial leaf wash, which is important when you are harvesting so much rainwater."

External cladding made from ZINCALUME® steel in the profile LYSAGHT MINI ORB® was used together with flat sheets of ZINCALUME® steel fixed over fibre cement sheeting for contrast. This was chosen for its non-combustible properties and striking aesthetic which really comes to life through the use of two contrasting profiles.

Design features:

• Roofing and walling made from ZINCALUME® steel and a steel framing was chosen as they are bushfire and termite proof and touch the earth lightly.
• A steel post and beam frame meant components could be fabricated offsite, easily transported and reassembled on the site.
• The roof is designed in a butterfly shape with 18 degree pitches which allow rain to drain to valleys which feed just two large rainheads, without the need for the guttering.
• A large rainwater tank was placed on top of the house so that water was available on site for the remaining building operations
• External cladding made from ZINCALUME® steel in two different profiles was fixed over fibre cement sheeting to create an aesthetic contrast.