GREY BASE HOSPITAL
Designed for Strength in a Seismic Zone
Earthquakes are a known risk in the town of Greymouth on New Zealand’s South Island, so when it came to replacing the town’s hospital with an up-to-date integrated healthcare centre, seismic-resilience was a prime design consideration.
The existing hospital – called Grey Base – was built in the 1950s on a natural ground escarpment, close to the estuary of the Grey River. Designing seismic-resilient foundations for a new building on this site posed a challenge, yet the location was convenient for serving rural communities on the West Coast, and the site was large enough to accommodate expansion.
With South Island’s largest tertiary hospital at Christchurch over 230km away, New Zealand’s Ministry for Health wanted a new hospital for the people of Greymouth that could provide 24-hour emergency services, critical care, acute and planned surgical and medical services, a maternity unit, and outpatient care, together with an integrated family health centre to support primary care provision. This multipurpose building must offer full functionality after an earthquake, and be designed for delivery on a tight budget.
We worked with architects CCM and Jacobs, to devise solutions to the unique challenges this project presented.
The building’s essential requirement was that it must be able to withstand extreme weather conditions and earthquakes. Ideally, the whole building would be designed to survive the severity of a ‘1-in-500 years’ earthquake – a risk classified under New Zealand’s building codes at Importance Level 4 (IL4). But as it was clear that this level of resilience for all parts of the building would be expensive to achieve on a hillside and riverside site, the project team created 3D models to test the proposed foundation structures under earthquake conditions in an effort to discover more cost-effective options.
The solution they devised involved designing the multi-storey main hospital building to Importance Level 3 (IL3), with seismic loads 130% of a standard building, and designing the attached single-storey family health centre wing to IL4, with seismic loads 180% of a standard building. This would mean that the family centre could be used for triage in the event of a very major earthquake, with patients transferred to Christchurch Hospital for critical care, if necessary.
Sufficiently robust to meet the hospital’s needs, this solution was selected. It reduced the overall costs of the scheme by over NZ$6M, leaving the Ministry for Health with more funds to channel into frontline clinical services.
As Grey Base is at least a three-hour road journey from Christchurch, the operating theatres in the new hospital are being equipped with technology that will enable specialist consultants to monitor procedures remotely and offer assistance when required. This capability will be particularly useful when the hospital is difficult to access.
Many of the clinical areas are designed for multiple functions to allow boundary spaces to be used for neighbouring departments as needed. The family centre will share resources and staff with the main hospital, too. The consulting spaces are designed to be flexible so that they can be used for general practitioner services, as well as hospital consultations.
The project will provide Greymouth with a new hospital that will offer 56 inpatient beds, three operating theatres, outpatient services, an accident and emergency department, services that include medical imaging, pathology, pharmacy, maternity, paediatrics, oncology and dialysis, a dental suite, and comprehensive family health services. Its design and buildings services will support the latest technological advances within a safe, modern and secure environment.