A Place to Call Home

Pushing the Sustainable Design Envelope on Military Barracks

The 13th Combat Aviation Brigade barracks complex at Fort Carson aspires to set a new standard in sustainability and functional design for the military barracks building type.

 

By J.J. Tang, AIA, M.SAME 

 


 

From day one, the design-build team for the $94.9 million 13th Combat Aviation Brigade (CAB) barracks campus at Fort Carson, Colo., has worked to achieve two key objectives: maximize building energy efficiency with a goal to adapt to Net Zero energy use; and create a lively and livable military residential community.

In order to accomplish these two overarching design objectives, the team of Mortenson/HDR broke down this massive 370,156-ft² barracks program into a series of residential, community-setting complexes, with required amenities to be thoughtfully integrated into the overall campus master plan.

Then each building was positioned with the best possible orientation to harvest nature’s abundant free energy.

13th CAB project, Fort Carson

13th Combat Aviation Brigade barracks campus under construction against the backdrop of the Rocky Mountains. All living units are northsouth facing with a 15° tilt towards the northeast. Energy models predict that by orientating the building towards north-south, it can harvest solar energy 25 percent more than an east-west facing building. PHOTO BY HARRY WEDDINGTON, USACE OMAHA DISTRICT


 

CAMPUS MASTER PLAN

As part of the design planning, the team studied various building configurations, orientations and site layouts, finally settling on a master plan comprised of three similar residential complexes.

Each complex will consist of a pair of four-story north-and south-facing barracks wings arranged in an offset H-shaped configuration and connected by a one-story link at the ground level. This design offers many benefits that other configurations might not have been able to achieve. 

  • All living units are north-south facing with a 15° tilt towards the northeast—the ideal orientation from a passive solar design perspective. Energy models predict that by orientating the building towards north-south, it can harvest solar energy 25 percent more than an east-west facing building.
  • The offset H-shaped barracks configura­tion offers three distinct spatial arrange­ments to form a livable residential community. One is a formal landscaped entrance courtyard in the pedestrian drop-off area, formed by the front of the offset H-shaped building wings. A circular, brick-paved plaza in the center of the entrance courtyard features an abstract graphic depicting a helicopter rotary wing, honoring the service of the 13th Combat Aviation Brigade. A sports courtyard also is formed by the back side of the offset H-shaped barracks wings. Two informal landscaped zones planted with native plants between each complex turn emergency access roads into pleas­ant jogging trails.
  • A highly articulated, glass-enclosed and vaulted ceiling entrance lobby node is designed for each barracks complex. This entrance lobby offers soldiers a place to relax and interact with others without causing any impact on living units. In the front and rear lobby full-height glass walls offer a visual connection between the front entrance plaza and the sports courtyard to form a cohesive complex. Soldiers who congregate in the sports courtyard and the lobby also are able to enjoy the view of the mountains to the west via highly transparent, full-height lobby glass façades.

These different spatial arrangements within the campus encourage social inter­action among soldiers and provide a variety of spaces for small or large social gatherings and activities. 

The building exteriors project a tradi­tional residential character and uses materi­als like brick scaled to human proportions. The colors chosen are similar to the warm tones one would expect to see in any high-quality residential neighborhood in America. The various spaces encouraging social interaction coupled with main-street residential aesthetics will make the campus truly a lively and livable community.

  


All living units are north-south facing with a 15° tilt towards the northeast—the ideal orientation from a passive solar design perspective. 


 

HOLISTIC APPROACH

The design-build team is taking a holistic approach to implementing sustainability, committing to achieve LEED Gold campus certification—not just certification for one building or complex.

The team examined the full breadth of sustainable features available to barracks building types and implemented those with a reasonable financial payback. The result is a design that leverages technology and harnesses the site’s natural surroundings and aligns with Fort Carson’s role as an integrated Net Zero pilot installation for the U.S. Army.

 

MATERIAL SELECTION

Sustainability begins with building mate­rial selections. The R-19 + R-30ci exterior walls consist of insulated structural precast bearing walls clad with thin brick veneer inserts. These insulated precast panels are from a local manufacture meeting PCI quality standards and include recycled content to provide a durable, secure and sustainable exterior. All four-story exterior wall panels of one complex were erected in a matter of weeks. Concrete floors were poured and windows were installed to provide a weather-protective interior work environment to ensure that interior construction could begin.

All exterior windows on the south façades have 3-ft deep, L-shaped alumi­num sunshades to mitigate Colorado’s harsh summer heat gain. Together with a high-quality Class A, R50 standing seam metal roof and high performance windows, these exterior enclosure materials provide the benefit of a durable and high energy performance envelope.

Due to the repetitive nature of each living unit bathroom layout, the team explored many options to provide better quality products and expedite construction. The team selected the pre-manufactured “bath­room pod” approach. The 498-living unit bathroom pods were pre-assembled and finished in a climate-controlled factory. The pods then were transported to the construc­tion site and installed in the opening on the floor slabs. The result is higher quality finish in all bathrooms and faster construction.

 

INTERIOR BUILDING SYSTEMS

A unique HVAC design—a radiant floor heating and cooling system—is being utilized to minimize energy consumption and maximize human comfort. This system is the most energy efficient for a barracks building type and the energy savings is in the range of 30 percent compared to conventional systems. Closed looped pipes with chilled or hot water circulating inside are embedded into the concrete slabs to heat the slab during the summer and cool the slab during the winter.

Much of the energy savings also is attrib­uted to the lower amount of energy required to pump water, as opposed to distributing air with fans. While a floor-radiant system alone is extremely effective for heating, to be effective for cooling, it must be supple­mented with an additional cooling source from the ceiling since the cool air flows downwards to the floor. To address this, a chilled beam system is designed within the overall HVAC system and incorporated into the gypsum wall board ceiling.

13th CAB Fort Carson project

 

Rendering of a completed barracks complex—a landscaped front entrance plaza and rear sports courtyard are connected via a glazed one-story entrance lobby. Various spaces are designed to encourage social interaction and make the campus a lively and livable residential community. HDR IMAGE


Another practical issue facing the design-build team, which could have a profound negative impact on the energy savings, is the issue of how to handle operable windows in all living units. For residential buildings, it is logical to have windows that can open and close. However, the traditional HVAC system design assumes that all windows are sealed. If windows were opened, all condi­tioned air would escape outside. Designers, contractors and facility owners traditionally have rarely considered the energy loss in this case, even thought it could very well be substantial. The solution the 13th CAB design-build team is implementing is to wire an automatic control sensor to each operable window of every living unit. When a window is opened, the automatic control sensor shuts down the HVAC system in that room until the window is closed again.

This approach has true sustainable value, since about six months of the year the weather in central Colorado is mild enough that air conditioning is not necessary and the windows can be opened.

 

HARNESSING RENEWABLE ENERGY

A consolidated energy plant for the chill­ers and boilers will support the entire 13th CAB barracks. A sustainable, consolidated energy plant maximizes the energy effi­ciency for the entire campus and simplifies future maintenance and operational needs, lowering the overall lifecycle cost.

Once the design-build team implemented all possible sustainable design strategies and cut the energy usage for the campus to the lowest possible point while maintaining human comfort, the next consideration was renewable energy. One of the proj­ect’s sustainability goals is to provide 30 percent of domestic hot water consumption through solar hot water panels. The team first designed for panels to be placed on the roof of each mechanical room. But it soon realized that more would be needed to meet the 30 percent goal. The placement of additional panels was studied in an effort to incorporate them seamlessly into the overall architectural design of the entrance plaza. There were three options: include solar panels and their support structure as an entrance plaza sculpture and shelter cover; build a covered walkway between the mechanical room and the main entrance; or build a shade structure for parking.

After detailed sun angle studies, the first two options were eliminated since the four-story south-facing barracks wing prevents direct sunlight on these solar panels for much of the morning. The third option was selected. Solar hot water panels were designed and incorporated into three parking shade structures adjacent to the mechanical rooms.

The team also incorporated solar photo­voltaic arrays to offset 24.8 percent of the annual energy consumption of a baseline building. These arrays were originally designed and placed adjacent to each of the barracks complexes. However, because of maintenance and safety concerns, as well as issues with sunlight reflecting out of the panels directly into some living units, they were relocated to the Fort Carson photovol­taic farm, which is not far from the site and is directly connected to the electrical grid.

 

SUSTAINABLE SHOWCASE

The 13th CAB Barracks campus is truly a sustainable showcase for the Department of Defense barracks building type.

The facilities push the envelope of sustainable design and construction and will provide 1,000 soldiers with a place to call home. The campus is currently under construction and expected to be completed in early 2015.

 


 

J.J. Tang, AIA, M.SAME, is Principal, Federal Programs, HDR Inc.; 773-867-7219, or This email address is being protected from spambots. You need JavaScript enabled to view it..