A Sustainable Future
’consume less - consume more wisely’ Day Bukh Architects
Essential for all sustainable homes is their receptiveness to the local environment. A passive solar house that uses the best orientation, and breezes will always use less energy than one that does not.
Achieving the best possible passive design has been a major theme of the design.
Another important theme has been to design a house that looks like a home, and not a house that has technical equipment attached to improve its sustainability. Ie. a sustainable house does not need to look sustainable, it just needs to be sustainable.
The Solution
Study of the local Tamworth environment resulted in the following solutions :
Thermal Mass, Stack Effect, Cooling Ponds, Shading Devices
To combat the very high diurnal temperature difference, in most cases above 18 degrees between night and day for all seasons. Large thermal mass is used to increase the time lag between heat loss and heat gain to stabilize the internal environment. This involves the use of load bearing masonry walls and roof (pre-cast concrete panels). The north facing living areas have a concrete floor. The exterior walls and roof to be lightweight cladding ranging from rendered insulation (type shown in illustrations), Compressed Fibre Cement, Bituminous Membrane, or Timber Cladding. The exterior lightweight framing houses service pipes and ducts, with penetrations into the house where necessary, ie. no chasing into the structural walls.
This form of construction provides thermal mass inside the house and enables the external walls to be well insulated. The internal walls and floor absorb the winter sun, releasing the stored heat in the evening after sunset, keeping the house warm, thus reducing heating costs.
In summer shading devices over the windows and doors block out direct sun, whilst the external insulation blocks heat transfer through to the interior, thereby keeping the house cool during the day in summer.
At night the house is cooled by opening the windows and drawing cool air through the house. Ponds placed to the south and north east further cool the breezes before entering the house.
The operable skylight and lower windows use the ’Stack / Chimney Effect’ to allow for natural cross ventilation regardless of the presence of external breezes.
The covered courtyard to the south stores cool air throughout the day to be used to flush the hot air out of the house in the evening. This is known as ’purging’.
The compact house, in terms of surface area helps reduce heat gain in summer and heat loss in winter.
Active Systems
The active systems incorporated into the design are :
solar hot water heater (glass tubes) placed above the skylights
solar cells / panels on the northen facade to generate electricity
rainwater tank under the bedroom terrace, the pond above provides a good insulator and thereby reduces evaporation
a gray water treatment pond located next to the rainwater tank
AAA rating taps and shower heads, and dual cistern toilets to reduce water use.
Energy saving appliances Compact Flourescents and LED lights to reduce energy consumption
Garden
Natural Australian grasses such as Kangaroo Grass
Productive garden
Possible black water recycling pond
