Green Prisons?

The environments we create for managing the occupants in detention and correctional facilities play an important role in the penal and rehabilitation processes.

While safety, security, and efficiency are obviously primary concerns, good design in these facilities should focus on creating healthy spaces and minimizing operating and maintenance costs. An energy-efficient, sustainably designed building can support a progressive approach to inmate rehabilitation and reduce electricity, fuel and water expenses for the operator of the facility.


In formulating a sustainable design strategy, an understanding of the challenges specific to detention and correctional facilities is critical.

Funding for sustainable strategies is virtually always a significant project issue. The budgeting and procurement processes are typically characterized by a design-bid-build or design-build delivery method — with a fixed maximum allowable construction cost — and do not earmark monies specifically for sustainable design features or LEED certification. In this context, integrated design solutions that shift costs of higher-value measures within the overall fixed construction budget are most effective — but only if functional requirements and challenges of the facility are clearly understood and sustainable design and other value-added goals are clearly identified as early as possible in the design process.

Quantifiable goals should be used whenever possible to target an anticipated level of achievement and to motivate the project team, and they should be integrated with LEED and other benchmarks, such as energy code performance, where appropriate.

Site: Correctional facilities often must be located in rural areas, where consuming green space for the project site and expending valuable resources to extend and build the necessary infrastructure is almost a given.

Ameliorating the loss of green space by creating a wildlife habitat on-site is not easy due to the requirement for clear, open areas that do not provide potential hiding places for escapees or others. In addition, parking lots must be quite large relative to other building types to accommodate parking for two shifts at once because of shift-change procedures.

For security purposes, high lighting levels are mandated at all times, which leads to high-energy use and the potential for “light trespass” on wildlife and neighbors.

Water: Due to the occupancy characteristics and residential use, water consumption at detention and correctional facilities is high. Kitchens, laundries and shower facilities require large volumes of hot water, and special construction requirements for plumbing fixtures in inmate areas limit the ability to specify equipment based on efficiency alone.

Energy: With buildings occupied 24 hours a day, seven days a week, correctional facilities are energy-intensive. Because most cells have toilet fixtures, by code they must be treated like toilet rooms, which means that a tremendous amount of air must be exhausted instead of recalculated, thereby increasing energy use by increasing the amount of heating or cooling of outside air above what would be required to condition recalculated air.

Opportunities to reduce lighting energy consumption through daylighting measures are frequently limited due to conflicts with security and privacy requirements.

Materials: Choices of materials for detention and correctional facilities are limited due to strict maintenance and security requirements, providing fewer opportunities to select greener recycled or rapidly renewable materials.


Just as an understanding of the challenges presented by the design of correctional facilities is key in successfully incorporating sustainable design features into projects, it is also important to be aware of the unique opportunities to include such features with moderate to no cost premiums or loss of functionality.

Site: If possible, consider brownfield sites such as abandoned landfills or industrial facilities that may be reclaimed for prisons in rural areas. In addition to reducing the loss of green space, using such sites may qualify the developing authority for financial or in-kind assistance from federal or state agencies.

For detention facilities in urban areas, siting the facility near public transit will significantly reduce the environmental impact from motor-vehicle use and offers the advantage of public-transit access to the facility by visitors and employees, which may reduce the number of required parking spaces.

Visitor parking requirements may be further reduced by furnishing facilities for video visitation, which allows the convenience of a visit through private live video and audio connections.

Water: While code-required stormwater detention systems are quite common, the extensive roof area of a low-rise correctional facility is well suited for collecting stormwater, which would otherwise need to be diverted. Instead, water is piped to a retention structure used for storing the water for building and/or site use.

Consider new water-saving technologies such as a PC-based water management system that allows security to shut off individual or group plumbing fixtures in a cell or cells, group showers, or individual showers rather than shutting down the entire domestic water system. Using treated recovered water (e.g., rainwater and air handler condensate) for toilet flushing or specifying self-contained gray-water penal fixtures that reserve individual lavatory wastewater for toilet flushing will also result in water savings.

Energy: Design a tight, energy-efficient building envelope that will generate savings in operational expenses and consider high-mass construction such as precast concrete to take advantage of thermal inertia to regulate the internal temperature.

In many applications, integrating a radiant heating or cooling system within the walls or floor will also cut energy use and cost, particularly in large open-plan spaces, and eliminate exposed mechanical devices within inmate areas. For air side systems subject to the extensive fresh-air requirements mentioned earlier, use heat-exchange technology such as enthalpy wheels or heat pipes to recover the energy from the exhaust air to help temper air delivered to other spaces.

The use of combined heat and power systems can be particularly beneficial for facilities with high demand for hot water, such as those with kitchens and laundry rooms.

Providing daylight and views in cells, dayrooms, and public areas where appropriate will not only create a calmer and more pleasant environment for residents and staff but also will permit lighting systems to be dimmed or turned off in response to daylight levels, saving energy and increasing lamp replacement intervals.

Materials: Maximize recycled content in materials traditionally used in correctional and detention facilities, such as steel or concrete.

When possible, source materials locally. This will both contribute to the local economy and reduce the use of fossil fuels in transport. Using efficient pre-engineered and preassembled housing components in precast or steel is a strategy to reduce construction materials and waste.

The Sustainable Future

Counties and states are becoming more aware of the substantial operating costs and environmental impact from high energy and water use. Several governing authorities have also begun requiring that projects meet LEED standards on buildings of a certain size, suggesting that correctional facilities of the future will be required to meet sustainable design standards.

Sara Graham is a sustainable design specialist in the St. Louis office of HOK, where she promotes the use of sustainable design practices in HOK projects worldwide. She is an editor of the revised edition of the HOK Guidebook to Sustainable Design and has written extensively on the subject of sustainable design. Stuart Lewis is an associate in the Atlanta office of HOK. Stuart is past chair of the AIA Atlanta Committee on the Environment and speaks nationally on green-building issues.

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