A02 Full Size
Interim Submission Teagan Lewis 55844 Tutorial 10 The assignment entails designing a roof for the Murcutt Guest Studio, of any chosen design, given it is not the same as the existing one. Structural Concepts I chose to work with a combination of a gambrel roof and a flat roof. The gambrel design covers the bulk of the structure, the studio, while flat roofs extend over the extension and decking. I did so as the main structural concepts I wanted to address were making economical efficiency with materials and structures, such as trusses, while also being able to evenly distribute loads, resist acting forces and also address a modern day push for greener design. The flat roofs were chosen over the extension and the decking to allow for a green roof application. The green roofs require structural elements such as a structural slab, a waterproof membrane, thermal insulation and drainage. The gambrel roof incorporates structural concepts including beams, such as hanging beams and strutting beams, ceiling joists, struts and under purlins, as well as eaves and drains (Wilkie, 2003).
Concepts explored included pitch, span, ride, crown, ridge, hip and valley.
Materials The roof I have designed incorporates quite a few different materials. The gambrel roof structure design used timber framing with galvanised corrugate steel roofing with a timber fascia board. Ive chosen these materials, as they are economical and easily accessible. The galvanised corrugated steel is waterproof and provides water protection for the timber to prevent rotting and decay. Timber is also relatively strong in both compression and tension; in collaboration with the steel they are likely to better resist lateral forces. The materials for the flat roofs are a little more complex, though shape is relatively simple. The roof requires a reinforced concrete slab, with a waterproof membrane, of high strength thermoplastic, thermal ventilation, drainage and a layer of clay below the soil for the plans to be able to spread their roots to and retain water. The waterproof membrane will prevent water compromising the steel framework of the concrete slab and allow water retention in the clays and soils so the vegetation can thrive in the man-made environment.
Construction A form model was constructed for my design. Included are original sketch ideas and drawings as well as photos of the finished form model. The form model was constructed for white pasteboard and connected with scotch tape. It is to provide an idea of the form of my design. It was difficult at times to work with the materials as scotch tape and pasteboard could not provide a completely rigid structure, sealed completely. I began with forming the walls of the structure and a base plate for the roof, which included the flat roofs and eaves and gutters.
Aesthetic Design In terms of aesthetics the setting surrounding the studio inspired me. An abundance of natural vegetation in harmony with the timber framework evoked a sense of nature. My design has essentially worked nature into the roof design, while bringing together history and modern technology. On first seeing the timber studio and envisioning a green roof I pictured an Old Norwegian house, as pictured to the right. Of course timber slabs were not ideal due to rotting but modern technology has allowed us to widen our material range to things such as concrete slabs. The green roof will also add some personality to the structure and encourage biodiversity, which will surely add some aesthetic value. Normal roofs are very bland and boring to look at but the colours and variation in vegetation will provide quite a view, as well as shading and cooling (Sydney City Council, 2013). The gambrel roof with a high pitch and glass window will allow for natural light to enter the building and make the space seem bigger.
Source: http://www.homedit.com/norway-green-roofs/ Source: http://www.cityofsydney.nsw.gov.au/__data/assets/pdf_file/0006/109383/Green-roof-resource-manual-full-version.pdf
Function A flat, green roof serves many functions. Providing natural soundproofing, thermal heating and cooling, increases biodiversity, reduces stormwater runoff, and reduces the heat island effect (Sydney City Council, 2013). Green roofs also allow for the production of food, extending the life span of the roof membrane and reduce the risk of fire (Sydney City Council, 2013). The gambrel roof serves a function of allowing for natural cooling, as the heat will rise to the steep of the roof. The laminated glass windows in the roof will also allow for natural sunlight.
References Wilkie, G 2003, Building your own home: a comprehensive guide for owner-builders, New Holland Publishers (Australia) Pty Ltd, Chatswood, NSW. Sydney City Council 2013, Green Roof Resource Manual, viewed 29th of August 2013