Canberra care

Architectural Review, The, July, 1994 by Peter Wislocki

Canberra may not be the driest place on earth, but it certainly gets very hot. This new hospital by Lawrence Neild shows how solar screening can modulate the internal climate while allowing patients and staff to appreciate the beautiful landscape.

Can healing machines make great architecture? The architect's own account of the genesis of Woden Valley Hospital's new diagnostic and treatment (D & T) building emphasises the pragmatic constraints: a tight budget, a fast-track contract, low anticipated maintenance costs, the restrictions of an existing masterplan, and the need for flexibility to accommodate complex and evolving clinical techniques. Such a building must be inexpensive to build and cheap to operate, and space planning can optimise scarce human resources.

The hospital's earlier building, an inarticulate oatmeal-coloured tower surrounded by sprawling, low-rise accretions, typified the quality of public health care buildings in Australia and throughout the world. The construction of the D & T building, which lies between the existing hospital campus and the major approach road, provided an opportunity to give the institution a new face.

The difficulties inherent in reconciling the institutional nature of public health care with the intimate needs of individual patients and members of staff have been clearly illustrated in a number of seminal projects in recent years. Ahrens Burton and Koralek's St May's Hospital, on the Isle of Wight (AR February '91) adopts humane planning strategies, with intimately scaled courtyards and care taken to reinforce the sense of identity of wards as communities within a larger hierarchy. The building's vocabulary, however, reinforces the notion of an efficient healing machine -- a pristine, polished assembly of objects in a green landscape.

At Woden Valley, as at St Mary's, the quality of the building's skin not only determines the building's superficial character, as perceived by patients and visitors, but illustrates the underlying strategy of its designers. Lawrence Nield's approach to the selection of cladding materials, from a detailed appraisal of many options, has been pragmatic, recognising restrictions of buildability, thermal performance, durability and budget (somewhat lessened by the depressed state of the local construction industry).

The use of relatively lightweight polished pre-cast concrete panels also avoided extensive scaffolding during erection. The panels are eucalypt green in colour, harmonising with surrounding vegetation, and subtly contrasting with the adjacent oatmeal tower. More importantly, they have a perceptible mass -- a sense of solidity and depth, visible at key junctions and in window reveals, providing a backdrop for lighter steel elements fixed to the facades. The concrete panels cover the main part of the most exposed elevations, with pre-finished metal used elsewhere. The cladding illustrates Nield's interest in refining a straightforward design to make it more elegant.

The overall strategy is just as straightforward. A 7.2m structural grid runs through the building's four rectangular concrete floors. Within the regular line of enclosure, five external courtyards are eroded. Otherwise, the steel-framed stud partitioning is demountable for maximum flexibility. the detailed space planning evolved in consultation with some 70 representatives of the hospital's clinical and ancillary staff. Layouts recommended by official planning manuals were modified according to individual staff preferences. This policy has been most evident in changes that allow the easy supervision of patient care areas from centralised staff stations.

Canberra's climate, technically classified as temperate, has average summer temperatures of 27 deg C, with maxima well in excess of 40 deg C. Air conditioning is unavoidable for most public buildings -- particularly health-care facilities in which sick patients and diagnostic equipment alike require highly controlled conditions. Woden Valley's system employs air-cooled chillers, eliminating the danger posed by Legionella bacteria, which has occurred in water-cooled chillers.

Energy is conserved by using condenser heat as a primary source of energy for the hospital's hot water, supplemented by gas-fired boilers.

If the servicing strategy of the building is unremarkable, the designers' attitude to other environmental factors is more noteworthy. Throughout the building all patients, even the very sick, are offered glimpses of the world outside. Ambulant patients are able to enjoy a breath of fresh air (or, as Nield naughtily suggests, a cigarette) within the building's courtyards.

The importance attached to achieving visual connections with the outside world has influenced the detailed design of the solar control louvres. The building's main facade faces west, presenting considerable environmental control challenges. Fixed metal blades cover the principal openings on all but the permanently shaded southern facade (the sun shines from the north in Australia). The size and orientation of these devices has been determined by sun path projections, but the designers have allowed some direct sunlight to enter the building late in the day and enliven the interior. Should sunlight penetration be undesirable, occupants can also control lighting and heat gains through secondary, internal Venetian blinds.