Sustainable technologies
In the design of the Plykit house we set out to create a simple kit of parts house that can be adaptable to the display of sustainable technologies.
It was important that the design methodology be translatable to the building of a house, and in this respect the house can be seen as a prototype modular home. Throughout the design process we always considered the use of the pavilion as a small home, farm shack, or artist retreat. The modular components of the house are equal divisions of the source materials, that being a 1200×2400 plywood sheet. This allows for each of the components to be relatively interchangeable, and also minimises offcut wastage.
Construction methodology
The principles of construction are:
- Prefabrication of components offsite
- Lightweight components able to be hand manoeuvred
- Assembly and disassembly by screw and nut
- Modular design to allow varied configurations
- Low embodied energy components
- Minimal wastage.
The house is comprised of a plywood box frame spine that serves to support the roof, and link the different areas and rooms of the house together along the spine. The width of spine is 600m which facilitates its use as cabinetry and benchtops for the kitchen, office and display area. The plywood boxes of the spine are bolted together with high tensile allen key bolts within a sandwich construction. The centre panel of the sandwich is sleeved into the floor structure, this is then bolted to the plywood boxes and then the roof brackets are slotted into the top of the sandwich. Therefore the whole building from roof to wall to floor is integrated into the one structural unit. The combined thickness of the sandwich panel is 60mm, which is an effective structural post but comprised of manageable components. The benefits of the plywood box spine serving both as a structural and joinery unit is to reduce the number of components required and ease in the transport and assembly.
Plywood information
The components are constructed generally from 25mm CD grade plywood. This material is lightweight and structurally stable, if it deforms under moisture or humidity it will return to its original dimensional shape. It is made from 25 cm diameter plantation logs in Australia. It can efficiently use thin layers of low grade timber within the panel, cross laminate them to improve their structural performance, and then have a finishing high grade veneer if appearance is required.
It is versatile as it can be used for wall cladding, interior shelving, interior benchtops, structural beams, lateral bracing and vertical loading. It is used as a structural and finishing material in the one component in the house and therefore is lightweight in its nature.
The plywood is CD grade which allows for greater variety of veneer and knotting on the surface veneer.
Painting the house
The timber in the live green house has been left unpainted as it was considered important for visitors to see the range of timbers used in the house. This includes Australian hoop pine veneer on the plywood panels, and a range of recycled Australian hardwood timbers such as spotted gum and blue gum. The characteristic markings of reused timber are apparent such as old nail holes and the typical wear and tear over the previous life of the timber. The timbers have been sealed with a citrus based oil. Painting the timber has been avoided as the texture and character of the timber is lost, the paint invariably loses its vibrancy and needs regular recoats to maintain its colourfastness, and the paint surface can compromise the future use of the timbers in their next reused iteration.