No place like dome
Domes have always had a bit of a 'nice idea - shame about the shape' response in UK architectural circles.
Ideally suited to underground buildings, given their structural form (the last time I saw one in polite company was at the Ideal Home exhibition in 1978), they have a certain hippiness associated with them, that has been hard to shake off. Perhaps that is why they are showing up in Australia, in a place called Sippy Down.
Denis Davis, a young designer in Queensland, is trying to reclaim the genre and has now built several sizeable structures for school buildings as well as the more usual dwelling houses. 'These are a feasible alternative to rectilinear buildings and very suited to rather hot climates, ' he says.
He has already built two buildings for the Montessori school, comprising 69 triangular glass-fibre panels, averaging about 17-21kg each.
Davis has also designed and built a number of luxury dome houses for private clients.
Well suited to prefabricated simplicity, the buildings comprise triangles of only two different patterns, although the apex skylight is a separate mould to take the large double-glazed 'acrylic bubbles'. By manufacturing a special triangular dual-glazed aluminium frame, designed from a boat glazing section, the skylight frame can accommodate a variety of thicknesses of highimpact acrylic. Thicknesses of 6mm or 10mm are even suitable for highcyclonic conditions.
Because of the way that stresses are distributed in the shell, in theory, half of the lowest ring of triangles could be removed. These non-load bearing openings can then be replaced by doors or windows, although by using translucent panels, dedicated window construction can be avoided. Linking domes together is a relatively simple process to provide modular extensions and corridors to other domes.
Steel soleplates and frames are bolted along the perimeter concrete footings. These are framed up to take low-level louvres as necessary. These have been provided for low-level passive ventilation, for instance, in the school buildings.
The triangular (or similar) panels are built up from this level. At junctions between panels, the joint is filled with butyl mastic and bolted together. It tends to be as easy as that.
Assembly is quick and efficient and the self-supporting structural form thus created provides a totally open plan. Davis' designs include freestanding mezzanine floors, partitioned rooms and spiral staircases.
For any given volume, the dome is the most efficient building form, paying dividends for energy efficiency as well as build costs. Because of its lightness, the geodesic dome can be fitted over basements or on top of conventional buildings.
Perhaps the Eden Project will help to legitimise dome architecture. Fifty years after Buckminster Fuller applied for a patent on a geodesic dome, maybe it is about time that we put away our kaftans and reconsidered the real value of the form.
The word on domes according to Denis Davis
I became interested in domes after reading Critical Path by Richard Buckminster Fuller.One of the many phrases that caught my attention was his Anticipatory Design Science. He believed our current building techniques would become less appropriate as we approached 2000 and beyond.
He proposed to revolutionise the building industry with the aid of the latest technology - using exotic lightweight materials. In the aircraft industry, weight and performance factors are critical, with design loadings at the ratio of 2:1. Design rates in the building industry are usually about 15:1. Quite clearly, the geodesic dome has the ability to house ever more people with the lightest weight-factors.
Put simply, when you load up a dome, it distributes the load over the whole structure.Because domes have many regular triangular, pentagonal and hexagonal panels they are much easier to massproduce. Having served apprenticeships as a sheetmetal-worker, boilermaker, aluminium welder and a boatbuilder, I felt that, as I found off-the-shelf products that could perform certain tasks, I could adapt these products to my dome structure and by doing so, make improvements to every one.
I have designed my buildings to be completely assembled by any builder, using standard tools and wood products. Almost all parts are simply bolted together and are prefabricated before arriving on site.
The building costs about AU$150,000 (about £50,000).
Contact Denis Davis by e-mail at armony@campac. net. au