Catastrophic weather events like wildfires are prompting more awareness of how climate change could affect operations in healthcare facilities and the staff and patients who inhabit these buildings. The pace of rising temperatures and heavy-rain events, however, has been slowly manifesting for some time, and newly released guidelines in B.C. offer a standard for approaching the planning and designing of capital projects from a resiliency perspective.
The Climate Resilience Guidelines for B.C. Health Facility Planning & Design culminates more than a year of multi-sector collaboration to develop practice-based guidance for B.C. Health Authorities. It arises from a series of reports and a provincial climate risk assessment, all with roots in the CleanBC plan, which was tabled in 2018 to meet legislated climate targets of reducing greenhouse gas (GHG) emissions.
Doug McLachlan, associate director of IBI Group, was on the task force that helped prepare this document, released in December 2020. “Prior to the guidelines, the process in deliverables may have varied depending from project to project,” he said. “There is now a framework established for how we can address climate change and look at going beyond LEED Gold or code minimum requirements on a project.”
He was speaking at a seminar in May, “Planning for Climate Resilience in Healthcare Facilities,” hosted by the Canadian Centre for Healthcare Facilities. As new request for proposal’s begin referencing these guidelines, the discussion covered how they align with key design stages and how climate resilience can be actualized in facility design.
Prioritizing Resilience From The Master Plan To Detailed Design
The guidelines include six overarching principles, from anticipating changes with climate hazards to considering co-benefits related to GHG mitigation and pandemic preparedness. There’s also a studied, yet flexible, climate risk and resilience assessment process with four steps to be reflected in every project design stage.
These steps are first actualized with an exposure screen, to incorporate hazards right into the budget at the master-planning stage. This informs what hazards the site is exposed to now and in the future. From there, a funneling process refines what is most vulnerable, prioritizes high-risk impacts like the quality of patient care, and confirms what design will move forward—making sure it aligns with other goals like COVID response. Ultimately, the design should comply with any resilience objectives that were flagged for reducing climate risks.
Since the guidelines are relatively new, no project has implemented all four steps yet. But there are many ways to realize them on the ground. Lisa Westerhoff, principal at Integral Group, shared her experience, speaking as a member of the project team that developed the guidelines.
For instance, when her team conducted a hazard output for a long-term care facility in B.C., they examined various climate data sources, the site itself, and the planning context to narrow down the scope of hazards and understand how expected changes in climate will affect them over time. “We then cross-checked that list with hazards required to be considered by LEED, so we could support the achievement of the resilient design pilot credit IPPC 98,” she said. “We were able to look at a broad range of hazards and make sure we achieved compliance with other goals as well.”
Designing For The Future Climate
“We need to be aware of the responsibilities of these key deliverables that will now be included on projects, such as climate risk assessment, perhaps additional concept designs early on and energy model options,” said McLachlan. He laid out some resilient design strategies for healthcare facilities.
From a site perspective, flooding can overwhelm local stormwater drainage capacity after an extreme rainfall—an event expected to increase in severity and frequency due to climate change.
“Many cities, such as Vancouver, had established minimum flood construction levels in flood-prone areas based on climate data,” he said. “As designers, we need to be aware because they are going to determine the ground floor elevations for access and egress out of the underground parking areas as well as determining location for equipment.”
Using the best available climate data for rainfall events will help plan a hospital for a lifespan of 50-plus years, he noted. The design should look at the 2100 Intensity Duration Frequency Curves and how those affect a site — exceeding a city’s requirements for its integrated stormwater management plan. This can also impact mitigation strategies like permeable pavement and green roofs. Reusing stormwater on-site for non-potable uses should be considered early on as some elements will affect the location of retention tanks.
Maintaining indoor thermal comfort
Prolonged periods of abnormally hot weather, higher humidity, with increased frequency and intensity figure into a long-term climate reality. “For patients and staff, it’s going to become increasingly more difficult if facilities are not designed for future climate conditions,” McLachlan stressed. The design of the cooling plant, mechanical rooms, shafts and HVAC systems are affected.
“As a principal on recent projects, we’ve looked at infrastructure that would be impractical to retrofit in the future, such as chilled water piping, to make sure that it is sized for 2080 peak cooling conditions, and there is space in the mechanical room for chillers and pumps to be added in the future as well.”
Daylighting and views
Since deep floor plates can create internal heat gains and little natural light, avoid them where possible and incorporate interior courtyards and multi-storey atriums to bring natural light as deep into the space as possible. Doing so will help avoid using artificial light and mechanically removing the resulting heat gain. Studies also point to a correlation between natural light access, quicker recovery, and staff wellbeing.
Building a better envelope
“By building a more efficient building envelope we can reduce the electrical load and therefore GHG emissions,” he said. “This is one of those co-benefits or synergies on the project.” He highlighted the benefits of improving the thermal performance of the windows with triple glazing, such as reducing peak heating loads, GHGs and annual energy use, and better visual and thermal comfort for occupants.
Anticipating Climate Stressors
Robert Bradley, director of energy and environmental sustainability, at Vancouver Coastal Health, and another project team member, deciphered between climate shock (extreme events like a heatwave) and climate stressors (prolonged events like a drought or increasing temperatures).
In response to specific stressors like air quality and extreme heat, Gordon McDonald, principal and director of engineering for Integral Group, and another project team member, touted more passive design solutions, rather than cutting-edge technologies. As he said, “I do believe for a building to be resilient, it needs to be simple.”
To build resilience to warmer summers and longer periods of hot weather, emphasize passive design solutions, such as building orientation, exterior shading, and maximizing window-to-wall glazing ratios, McDonald said. Orientating a building from east-west, rather than north-south removes problematic solar control on the west facade, which leads to large cooling loads.
Solar shades above windows are efficient for high sun angles, while planting deciduous trees provides shade in summer and allows sun penetration in the winter. Glazing can also control solar heat gain with photovoltaic glass that limits the amount of heat coming into a building.
While reducing cooling loads, buildings must remain resilient in 2050 and even 2080 when temperatures are no longer at their current levels. As McDonald said, there are weather files now available that designers can refer to when calculating how many chillers will be needed in the future. To avoid replacing broken equipment, the idea is to install them at a later date, while making sure there is ample space in a mechanical room, enough electrical capacity, and that chilled water piping is sized for the future to avoid costly and disruptive retrofits throughout the facility.
Design solutions to protect against forest fires and airborne viruses include vestibules on all main entrances and tighter envelopes to hinder air infiltration, thus reducing outdoor contaminates. There should also be space allocated for the installation of future filters, intake louvers on different facades, and increased humidity levels of 40 to 60 per cent, as viruses spread more easily in lower humidity ranges. The minimum CSA range stands at 30 per cent
Minimizing the energy associated with buildings comes down to passive design methods like massing, orientation and solar shading, and building better envelopes, roofs and windows, which also reduce carbon emissions. “On the west coast, we’ve seen Passive House get some traction recently, not necessarily in healthcare, but residential, institutional and commercial,” said McDonald. “What this is doing is driving down those energy targets, so we’re using less energy inside the building.”
Since healthcare facilities move a lot of air throughout the building, a portion of which is outdoor air, the idea is to ensure the energy associated with heating and cooling is minimized. This translates to heat recovery ventilation, energy recovery ventilation, thermal wheels, or active heat recovery, which involves taking energy from the air, sending it through heat pump technology, and using that to preheat domestic hot water or heat or cool a building.
In B.C., where electricity is hydrogenated, McDonald is seeing a trend where more buildings are choosing heat pump-driven technologies to achieve low emissions. “The move is to green the grid,” he said. “And if we could move to a more electric building solution that would make us more resilient in the long term.”