The pathway to community-positive health care design

LEED Fellow Colin Rohlfing shares HDR case studies in health facilities that are also environmentally friendly.

Health care organizations serve the people of their communities for both critical care and preventive health, striving to meet the Hippocratic Oath to foster wellness and do no harm. However, they face certain challenges that, if not properly managed, can work against these goals. The environmental pollution that these facilities often generate can lead to both acute and chronic health issues, and emissions from on-site utility plants and backup generators can impact air quality in the surrounding community.

Another challenge is the medical and pharmaceutical waste generated, known as the pending "endocrine crisis." If improperly managed, medical waste can seep into nearby waterways due to improper disposal or the inability of waste treatment plants to filter out such substances. Prolonged exposure to certain medications in drinking water can disrupt endocrine systems, leading to long-term health issues, such as fertility problems, infant mortality and developmental issues.

The health risks to the community can be far-reaching. This begs the question: How can health care organizations apply more holistic design approaches to achieve positive community benefits?

The following design approaches and associated case studies have helped HDR clients understand nested ecological and social systems to strike a balance between patient care, operational efficiency, and ecological and community health.

The community impact of energy and carbon

Hospitals are inherently energy-intensive due to:

• Continuous, 24/7 operations
• 100% outside air systems
• Advanced filtration that increases HVAC static pressure
• Pandemic resiliency requirements with patient room conversion to energy-intensive ICUs
• Specialized medical equipment
• The sheer size of most facilities

These conditions are intended to minimize infections and improve patient care, but they seem to be working against the desire for positive community impacts. In order to address these realities, HDR executes the following steps to get our projects below 100 kBtu/SF/year and toward regenerative impacts.

Steps for a carbon-positive hospital. Graphic credit: Duncan Griffin, HDR.

These steps take a "fabric first," or envelope first, approach to design that dispels the myth that the envelope for a high internal load-driven building does not have a significant impact on energy use. By limiting the peak solar load to 2-3 watts per square foot, we can specify low-energy radiant or displacement systems while downsizing all aspects of the HVAC systems. This includes terminals, ducts, air handling units and chillers. These efficient systems would not be possible without detailed modeling of reduced peak solar loads.

It is important to note that another myth can be dispelled with this approach. An all-glazed solution for a patient room that only consists of a 20-foot depth for occupied space does not provide appropriate levels of daylight. The only results in an increase of glare, visual and thermal discomfort, and a condition where healing views are blocked due to shades being down for a majority of the time.

"The most critical part of making hospitals more sustainable is improving the patient care journey," says Duncan Griffin, LEED AP BD+C, director of sustainability, health at HDR. "A better building envelope can lead to a reduction in the velocity of air needed, creating a setting for better patient comfort. Fundamentally, if patients are not recovering due to poor thermal, visual and acoustic comfort, the building is not doing its job."

Maximum peak solar load for low-energy systems. Graphic credit: Duncan Griffin, HDR.

Humber River Hospital (HRH) is an example of this approach in action:

Humber River Hospital | Ontario, Canada

Serving more than 850,000 people, the 1.8 million-square-foot, LEED Gold hospital is the largest acute care center in the Toronto area. Humber River's "lean, green and digital" vision inspired an unprecedented energy target; according to HDR data, its energy, water and greenhouse gas emissions are respectively 50%, 88% and 51% lower when compared to a similar hospital benchmark.

The team at the hospital, "HRH," understands and deeply cares for the community that it serves. In early design stages, it was identified that HRH provides care to a significantly higher proportions of elderly, minority and disadvantaged populations. These groups have higher disease prevalence rates for diabetes, asthma, high blood pressure, COPD and addiction compared to other demographics.

It is important for designers and the health industry to start to quantify the negative impacts our buildings are having on these population. According to research by the Canadian government, 6,600 premature deaths are caused by pollution annually in Ontario, and health care emissions are responsible for 4.6% of Canada's total emissions. An estimated 264 premature deaths are caused by health care facility emissions in Ontario. HRH leadership was committed to not contributing further to these community health issues through their design and operations.

With this in mind, the hospital implemented as many of the following carbon reduction strategies as possible:

Manage peak solar loads and optimize daylight:

• 28% weighted window-to-wall ratio
• Electrochromic glazing
• Peak solar load below 3 W/SF
• 50% vegetated roof and reflective roof

Zone air handlers and controls:

• Ventilation set-backs for patient rooms and operating rooms
• Low-velocity ducts
• Zoning to reduce reheat loads

Use heat recovery/exchange:

• Heat recovery chiller
• Enthalpy wheels
• Stack economizer
• Dedicated chilled water loop for equipment loads

Humber River Hospital © 2025 HDR, Inc., all rights reserved.

The community impact of water

Hospitals require vast amounts of water for patient care, sanitation and medical procedures. The primary concern is reducing water consumption without compromising hygiene standards.

Roughly 80% of water use in a health care environment consists of process water loads associated with mechanical systems, medical equipment such as sterilizers and reverse osmosis (RO) reject. Just focusing on water-efficient fixtures will not achieve the significant reduction that is required for positive impacts.

HRH implemented a reuse system for cooling tower makeup and irrigation, incorporated a process water reuse loop, and specified ultra-efficient sterilizers to reduce overall water usage by roughly 88% from a typical hospital.

These reductions were able to reduce the impact on the local wastewater treatment facility, but more important, the stormwater captured for this reuse improves the Humber River water quality and reduces the potential for flooding downstream-an event that has had catastrophic impacts on the nearby community in the past.

This focus on the importance of water and its relationship to community impacts can also be seen at the Almossa Rehabilitation Hospital in Saudi Arabia, the region's first LEED Platinum hospital.

Almoosa Rehabilitation Hospital | Al-Ahsa, Saudi Arabia

The Almoosa Rehabilitation Hospital is a 610,000-square-foot, 300-bed facility in the eastern province of Saudi Arabia. The building embodies the essence of an oasis-like landform, fostering a deep connection with nature and enhancing the healing process.

A sophisticated water reclamation system reclaims both condensate from the HVAC infrastructure and greywater to support a biophilic water feature and appropriate levels of vegetation.

The project also adheres to a "fabric first" approach by minimizing peak solar loads, which is especially important given the climatic realities. The undulating shading device that shields the facility from the harsh elements evokes the ceaseless movement of sand dunes. Expressing the human instinct to care for our most vulnerable, the sinuous screen is designed to parametrically change from façade to façade to compensate for the solar heat gain of its specific location and function.

Almoosa Rehabilitation Hospital. Photo courtesy of HDR © 2024 Gerry O'Leary.

Using LEED as a framework for success

One of the leading frameworks for achieving performance in health care is the LEED rating system, which provides unique requirements for hospitals.

The LEED for Building Design and Construction: Healthcare guidance addresses the unique challenges and needs of health care facilities and can help move toward community-positive impacts. Guidance around infection control, occupant health and well-being, and medical waste management focuses on creating healthy environments for both patients and staff, addressing factors such as lighting, acoustics and air quality through enhanced ventilation and filtration, which can all contribute to better recovery outcomes and enhanced staff productivity. Requirements for medical waste management encourages hospitals to adopt practices for handling hazardous and nonhazardous waste, including on-site treatment, recycling and waste-to-energy solutions, reducing landfill reliance and contamination of nearby soil and waterways.

To date, nearly 4,000 health care projects are either registered or certified using LEED. This is a testament to the impact that the LEED rating system is having on this unique building typology.

What the future holds

While these projects are at the "bleeding edge" of performance for buildings of this typology, they are not yet having a net positive or regenerative impact on their respective communities. More needs to be done to achieve net positive targets for carbon, water, waste and associated human health. Through the adoption of advanced technologies (bio-digesters, solar hydrogen, wastewater heat recovery) and a focus on emerging KPIs such as equity and embodied carbon, we can all continue to push the needle toward true regenerative design.

The following projects are currently in design or have broken ground:

Prince Edward County Memorial Hospital | Picton, Ontario

The Prince Edward County Memorial Hospital in Ontario aims to become the first mass timber hospital in North America designed to be net zero carbon-ready. Geothermal energy exchange, building integrated photovoltaics, a high-performance building envelope, indigenous landscaping, composite wood cladding and green roofs, among other sustainable measures, prepare the building for future electrification and net zero carbon status.

Prince Edward County Memorial Hospital energy strategies. © 2025 HDR, Inc., all rights reserved.

UCSF Health Helen Diller Hospital | San Francisco

The University of California San Francisco Helen Diller Hospital hosts a completely Red List-free design that prioritizes equity through the incorporation of an elevated public park. The park serves as a resilient heat-stress haven for the nearby community, many of whom do not have access to proper air conditioning.

UCSF Helen Diller Hospital. Image courtesy of HDR Inc.

Projects like these are proof that these technologies and focus areas are in development today and are not limited to some distant future. With the typical hospital design process lasting 5-8 years, we must be pushing these ideas today.

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