The renovation of the ASHRAE Headquarters project maximized operational energy performance through simple design measures including: a reduction in the window-to-wall ratio (WWR), the addition of continuous exterior insulation, high performance glazing, and sunshades tuned to orientation and site conditions. (Photo/Jonathan Hillyer)

McLennan Design, in partnership with Houser Walker Architecture and in collaboration with Integral Group, have completed the renovation of a new headquarters building in Atlanta, Georgia for ASHRAE, the professional association of heating, ventilation, air conditioning, and refrigerating engineers. The design team was tasked with renovating to Net-Zero Energy performance levels a 69,000-square foot office building constructed in the 1970s. Because of the technical nature of the work performed by the client, the design called for the very best in thermal conditioning and energy-efficient enclosures. ASHRAE, founded in 1894, is a not-for-profit global society advancing human well-being through sustainable technology for the built environment. ASHRAE funds research projects, provides continuing education programs, and develops technical standards for the advancement of HVAC&R systems design and construction, and is comprised of over 56,000 members worldwide. The renovation hopes to serve as a benchmark for deep energy-efficiency retrofits and provide a healthy, biophilic, and productive work environment for ASHRAE’s employees and the volunteer committees that serve the industry.

Reuse of the steel bridge and canopy structure reduced the project’s embodied carbon, while providing a modern, protected entryway experience. (Photo/Jonathan Hillyer)

“We knew the Integral team and architects were going to have to be on their A-game, because we had a very educated client,” says Stanton Stafford, principal of Integral Group.

The task was to turn this energy-consuming, 1970s building into a net-zero energy, global headquarters fit for its client – ASHRAE, CIBSE’s transatlantic sister organization. In addition to net-zero energy consumption, ASHRAE wanted its new HQ to exceed the provisions of its own indoor air quality standards and to deliver a maximum demand-side energy use intensity (EUI) of 67.5kWh/m² per year (21.4kBtu/ft² per year), a figure consistent with the society’s Advanced Energy Design Guide for zero energy office buildings.

The building ASHRAE purchased was a typical out-of-town office, comprising two rectangular, three-story blocks to the east and west of a glazed, barrel-vault atrium linking the two. A cast-in-situ concrete frame supported the building above a large basement, which included plant space, and the exterior was clad in alternating horizontal rows of precast concrete and glazing.

The new ASHRAE headquarters is a prime example of adaptive reuse, giving new life to a mid-century building. Buildings such as this and many others found in sub-urban office parks are ubiquitous in nearly every climate zone. This project demonstrates what is possible in one of the most challenging climate zones, located in a part of the country where the construction labor market has little tolerance for any unusual construction techniques or technologies. If this sort of high-performing transformation is affordable and possible in the booming but traditional Atlanta construction market, it is possible anywhere. From the outset, the goal of the project was clear: to celebrate off-the-shelf, simple technologies and the role engineering can play to deploy that equipment in new and innovative ways.

The new atrium roof and skylights provide improved daylighting and eliminate the potential for overheating – a problem frequently encountered with the previous fully-glazed, barrel-vaulted roof. (Photo/Jonathan Hillyer)

The design team ensured the building is net-zero-ready, analyzing the solar potential of the roof area and designing the retrofit Energy Use Intensity to match. As PV panels prices drop, the building will be fully prepared to install a solar array within the available roof area and integrate on-site energy production into all the electric building operations. Interior loads were also reduced as much as possible to keep the size and cost of future PV system to a minimum. There are countless office parks across the country with 1970s-era buildings similar to the one acquired for this project – buildings with ‘solid bones’ that merely lack the modern technologies and systems able to accommodate resource conservation ethics.

These buildings are also beginning to leak and require major maintenance upgrades. The new ASHRAE HQ exemplifies how to reinvest (modestly) in a 40-year-old structure so that it can be a useful contemporary workspace for another 50 years. By maintaining the existing structural elements, this project dramatically reduces the embodied carbon typically inherent in new construction.

By investing in a new enclosure, the project will now perform as efficiently as new construction built to net-zero energy standards. What once were dark and depressing interior spaces have now been transformed with higher ceilings, daylight, and views for all staff.

By reusing the concrete structure and tilt-up wall panels, the ASHRAE Headquarters reduced embodied carbon substantially compared to new(steel frame) construction. Bringing people into the daylight was a key strategy during the programming phase, prioritizing the upper floors for regularly occupied workstations and placing the less-frequently occupied training spaces on the lower levels. (Photo/Jonathan Hillyer)


Founded in 1894, ASHRAE is a global leader in the advancement of human well-being through sustainable technology for the built environment. As an industry leader in research, standards writing, publishing, certification and continuing education, ASHRAE and its members are committed to shaping tomorrow’s built environment today through strategic partnerships with organizations in the HVAC&R community and across related industries. For more information and to stay up-to-date on ASHRAE, visit and connect on LinkedInFacebookTwitter and YouTube.