Sue Cartledge investigates environmentally sustainable design and fitout of healthcare facilities in the light of global climate change and peak oil.
The topic of environmentally sustainable design (ESD) will become increasingly important over the next decade and was looked at in some depth at a recent conference in Brisbane, Green Hospitals.
The healthcare sector must consider ESD when any new buildings are planned or older ones refurbished.
Two people who are deeply involved in ESD are engineer Anthony Marklund, an associate at Umow Lai & Associates in Melbourne, and architect Digby Hall, a faculty member of the Green Building Council of Australia (GBCA), who runs Genus Loci in Sydney.
Marklund has been involved in a large number of ESD healthcare projects, including aged care, acute and sub-acute mental health, regional hospitals, major urban tertiary hospitals and healthcare research facilities. He presented on design approaches and technologies to greening healthcare at the Brisbane conference.
Hall has also been involved with designing aged care and healthcare facilities . His role within the GBCA is delivering Green Star Accredited Professional training to the property industry.
For Marklund, the chief objective of a healthcare building is to provide a healing environment, “the concept of which is intrinsically linked to ESD.
“However this simple symmetry of function with sustainability is somewhat complicated by the functional requirements of healthcare buildings,” he says.
“Accepted design guidelines which conflict with many sustainability principles are progressively being challenged in the design industry. For example recent international research suggests that natural ventilation is better than High Efficiency Particulate Air (HEPA) Filtration for infection control purposes.
“In a way this is commonsense – people are happier when they have connection to the outside, and happier people heal faster! “
Hall says the building’s impact on its occupants and users is just as important as its impact on the environment through its construction and operation.
“Green buildings inherently deliver healthier environments for people, and obviously this is the highest priority in delivering healthcare buildings.”
There are a lot of individual aspects to ESD — energy savings, water recycling, waste minimisation, use of recycled or
sustainable materials, more efficient use of space — and no one factor is the most important.
Both Marklund and Hall say that by committing to ESD early in the development process, key sustainability aspects can be identified during the design process to achieve a holistic, balanced ESD approach.
In fact, Marklund says, the most effective engineering approaches resolve two or more ESD factors in one synergistic system.
“For example, waste-to-energy systems reduce waste and carbon emissions while generating energy, while grey water recycling systems save water and can increase energy efficiency and reduce carbon emissions when the recycled water is used for cooling water make-up in closed circuit coolers,” he says.
“The limits to achieving benefits spreading across sustainability principles are only constrained by the resourcefulness and will of the people involved in a project.”
The cost factor: is ESD more expensive?
There is no simple answer to this, but the consensus seems to be that over the life of the facility, ESD is relatively cost neutral, while providing the benefits of reduced waste, energy use and carbon emissions.
“For new buildings, focus on committing to ‘green’ on day one – a green building shouldn’t cost any more if it’s in the hands of a good design team,” Hall says.
“Most of the big wins with green buildings are through good design and common sense.”
“Aspects such as building location, orientation, floor plate depth, sun shading and insulation are all relatively cost neutral (if not cost saving in the long term), yet deliver compounding interest as far as building performance and comfort go. Recent experience is starting to demonstrate that solidly performing green buildings can be delivered within standard budgets.”
Marklund adds that many energy or water conserving, low environmental impact or high indoor environment quality building systems are within the same capital cost range as conventional systems.
“When combined with passive design, cost-effective systems such as mixed mode ventilation, water efficient fixtures or efficient lighting systems can substantially improve environmental performance compared to a conventional design. Such systems which combine two or more sustainability functions can also reduce overall cost of implementing sustainability.”
Passive design – a key to ESD
Whether or not additional funds are available to a new building project, Marklund says that it should be designed according to passive design principles along an integrated design process to achieve best cost-effectiveness.
Passive design includes orienting and shaping the building to control sunlight and heat in summer and allow it in winter, to optimise daylight and air for habitable spaces, to provide the right balance of air-tightness and envelope thermal performance, and to use naturally occurring effects to benefit the building environment.
These effects include use of thermal mass for indoor comfort regulation, diurnal ambient temperature variations for heat rejection, and the stack effect for natural ventilation, he says.
” ‘Integrated Design’ is an iterative design process which has feedback loops to optimise the design of the building form, followed by sub-elements and sub-systems, usually through building modelling and simulation techniques.
“In this way the engineering aspects affect the architecture, which is in stark contrast to the conventional ‘straight-line’ design process where the engineering is simply a response to the architecture.”
Refurbishing: look for long-term savings
Older facilities need not continue to have a large environmental footprint, and can incorporate ESD factors into a refurbishment program.
“For refurbishments, I would suggest a strategy of investing in initiatives that deliver long term savings,” Hall advises.
“Within any budget we should identify the initiatives that are going to deliver the largest environmental benefit whilst maintaining the comfort and amenity for the occupants.
“The first step would be to reduce the heat load on the building, through sun-shading and improved insulation. You should also take the opportunity to improve HVAC performance – focus on delivering good clean air with less energy.
“These aren’t necessarily exciting things to do, but in the past we have been amazingly poor at delivering common sense design. Even establishing appropriate landscaping around the buildings can improve the building’s performance and comfort.”
Other than these simple changes, he advises getting a tailored solution, as ‘green’ buildings require site-specific and building-specific responses.
Marklund agrees that large efficiency gains can be achieved by improving the facility’s thermal envelope performance. The most cost-effective way to do this, he says, is to improve roof insulation levels and facade air-tightness.
“Cost-effective engineering solutions should also be investigated, such as relamping or adding controls to light fittings, improving HVAC and hot water systems efficiencies by adjusting controls and setpoints or introducing an economy cycle.”
What about the actual materials used in fitout and refurbishing? Are there environmental considerations?
“Truly ‘green’ buildings should also take into account the ‘upstream’ and ‘downstream’ impacts of the materials they use,” Hall says.
“The choice of healthy indoor materials with low levels of VOCs (volatile organic compounds) and formaldehydes can also provide healthier environments.
“For example, the use of PVC (Poly Vinyl Chloride) is one such material that uses known toxins in its manufacture.”
Alternatives include HDPE (High Density Polyethylene) for piping and polyethylene or steel for conduits.
He agrees that flooring is a challenge in the healthcare environment, with its demands for durability and infection control. Alternatives to PVC can include linoleum, natural rubber, cork, or any composite floor coverings that do not include PVC.
Key points of ESD
– ‘Green’ buildings deliver healthier environments for people
– Passive design is a key to ESD
– ESD is relatively cost neutral, while providing the benefits of reduced waste, energy use and carbon emissions
– Large efficiency gains can be achieved by improving the facility’s thermal envelope performance
– ‘Green’ buildings should also take into account the ‘upstream’ and ‘downstream’ impacts of the materials used.