Commercial buildings’ forms depend upon the area of the site and the amount of working space required. If the client needs a large floor area but the site is small, then a multi-storey solution may be called for. A larger site may accommodate a single-storey building. In the Adelaide suburbs and Adelaide Hills, council development plans usually demand car-parking adequate for customers and employees be provided, and this may take up a lot of space. In multi-storey commercial buildings, carparking can be located in the building undercroft. Boundary setbacks – how many metres building walls may be from a site boundary – are set out in the Building Code of Australia, and council development plans. It’s permissible to build up to a side or rear boundary as long as the walls are of fire-proof construction, otherwise they may have to be up to 3 metres away.
Commercial Buildings in the Adelaide Hills usually have to fulfill three major categories:
The Function
Fit for purpose: the Adelaide Hills commercial building has to be right for its function. It must be accessible: it must be visible from the street and easily accessed off the street by the cars of customers and staff, and any trucks which are going to service it. The front of the building should have room for signage – on high, visible above the traffic and lower down too, so that it’s readable from closer in. The carpark should be designed so that it’s easy to use, preferably with entry and exit separated, and wide cross-overs. The front entrance should be visible and easily accessed from the carpark. It’s a requirement that parking for disabled is closest to the entrance. Steps into the building should be avoided. A single-storey commercial building is the cheapest per square metre of floor area, but often the site is too small for all functions to be at ground level. A mezzanine floor is one option, or a full multi-storey layout may be called for. If so, one or more lifts would be necessary. All staff and clients must be able to reach the upper floors without having to climb stairs. Escalators are an alternative option for access between floors; they are expensive and take up a lot of space, but are better than lifts for being able to move a lot of people. If your commercial building is to house an industrial process or is for bulk storage, then you might need a large area of column-free floor space and plenty of head room; these needs are achievable using steel portal frames.
Form
The most basic element of a commercial building is its floor. In South Australia, floors are usually concrete. In the Adelaide Hills sites are often sloping; this usually means that there’s some need to cut-and-fill the site to create a bench for the building. Retaining walls may be necessary to stabilise ground which has been cut, and the volume of fill, and concrete piers to support the walls or floors above unconsolidated fill. The building’s walls may be masonry – brick or concrete, or metal – corrugated ‘Colorbond’ steel sheeting or aluminium panel. The Building Code of Australia demand that walls on or close to site boundaries must be fire-resistant, so masonry may be necessary. Metal walls are OK if not closer than 3 metres to a boundary. For the same reason, windows are not permitted closer than 3 metres to a boundary. Windows are usually required for natural lighting and ventilation and display of merchandise; large expanses of glazing must comply with the Glazing Code, which sets out glass thicknesses. In the Adelaide Hills, the climate – cold in winter and hot in summer – means that buildings have to be detailed to conserve energy. This means that insulation is necessary for walls and roofs, and double-glazing may be necessary for windows. Windows’ orientations – north, south, etc,- factor into the energy rules. In some areas of the Adelaide Hills, bushfire resistant building is mandated; external walling and roofing may have to be ‘non-combustible’ and glazing may have to be ‘toughened’.
Construction
The costs of building commercial buildings in the Adelaide Hills are usually comparable with those in Adelaide generally, but may be affected by site works – cut and fill and retaining walls – , on-site wastewater treatment, energy conservation rules, and in some areas, bushfire-resistant construction. The Hills generally have local resources, of materials and skills, comparable with Adelaide generally, for most medium-scale commercial projects.