We all want to live and work in a strong community. Preserving and enriching our communities with sustainable design practices makes good sense for everyone. At HOLT we assist communities and community organizations avoid the degradation of our un-built environment, conserve natural resources, support the local economy, and plan future development to maximize livability.
What is sustainability?
Sustainability, from the Latin sustinere (to hold up), is, in its broadest sense, the capacity to endure. In 1987 the Brundtland Commission of the United Nations defined sustainable development as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs." Others have challenged this definition, asking how any development can be sustainable. Many see sustainability as a balance of three overlapping and often competing systems: environment, economy, and society.
At HOLT, we recognize that development is needed to support and advance societal goals, and we endeavor to achieve social, economic, and environmental sustainability in all that we do.
In December 2005 the American Institute of Architects issued its Sustainable Architectural Practice Position Statement:
The profession is confronting the fact that buildings are the largest single contributor to production of greenhouse gases and almost half of the total annual production. As architects, we understand the need to exercise leadership in our role in creating the built environment. Consequently, we believe we must alter our profession's actions and encourage our clients and the entire design and construction industry to join with us to change the course of the planet's future.
Accordingly, HOLT has joined the AIA 2030 Commitment toward realizing a goal of net zero carbon emissions in new buildings and renovations by the year 2030.
What is LEED?
The LEED Green Building Rating System is a voluntary, consensus-based national standard for developing high-performance, sustainable buildings. It provides a vehicle for quantifying and comparatively evaluating the degree to which any project achieves sustainability.
In the current version, LEED 3.0, there are a total of 110 possible points divided among seven categories: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, Innovation in Design, and Regional Priority. Within the categories there are prerequisites, which must be satisfied, as well as optional points from which to choose. There are four levels in the rating system, with the minimum points required for each indicated in brackets: Certified , Silver , Gold , and Platinum .
What is a LEED AP?
A LEED Accredited Professional is a trained individual who has passed a test administered by the U.S. Green Building Council. Many of the professional staff at HOLT are LEED APs.
What makes a building "Green"?
As noted above, there is a vast array of possible strategies for making a project sustainable, and many levels of sustainability. In general, we at HOLT strive for maximum attainment in energy conservation, resource management, and indoor environmental quality. Actual strategies depend on the type of project, the owner's priorities, and the particulars of the building and the site.
How much more does it cost to build "Green"?
This is a difficult question to answer, because it depends on the baseline standard against which the sustainable project is measured. In higher education, where the norms of construction are set at a fairly high level, the increment to achieve a moderate measure of sustainability can be quite small. Often the life-cycle costs can be capitalized to completely offset any increase at all, particularly when energy conservation is emphasized.
Besides the construction cost increment, there are additional design costs associated with "Green" buildings. Non-standard energy sources, like geothermal or solar, require specialized engineering in addition to the usual systems design. To optimize building envelope and operating systems, digital energy modeling is a necessary part of the design process. Commissioning is a pre- and post-construction engineering process that helps to insure that operational systems perform to their intended levels of efficiency.
If the project is registered to pursue actual certification, there are additional costs for the substantial amount of documentation required. The actual cost will vary with the size of the project, which points are pursued, and the level of certification sought. As a general rule, a range of 0.5 percent to 2.0 percent of construction cost could be anticipated.
Why should my project be "Green"?
The reasons for sustainable design are as varied as the projects themselves. In the broadest sense, the preponderance of scientific thinking supports the concern that an excess of carbon dioxide in the atmosphere is leading to destructive and accelerating climate change. With nearly half of those emissions coming from buildings, it is important for present and future generations that we strive toward carbon-neutral development.
On a smaller scale, energy costs are increasing at rates in excess of inflation, and designing for reduced energy consumption will pay dividends for the life of the building. In some parts of the country the cost of water is experiencing similar increases, and water conservation measures can have economic as well as environmental benefits.
Improved indoor environmental quality is a feature of sustainable design that everyone can enjoy. When indoor air is free of volatile organic compounds and toxins like formaldehyde, people using the building are happier and healthier. When spaces have windows and daylight, studies have shown that learning and productivity improve. And when spaces have localized control of temperature, humidity, and fresh air, inhabitants are more comfortable. All of these improvements make a project more valuable.
A LEED Certification plaque is not necessary for a building to be "Green," but it is a third-party validation that can itself have market value. As a college or university seeks to attract students from a cohort who increasingly are concerned about a sustainable future, campus projects with LEED Certification help to demonstrate the institution's commitment to sustainability.
What would be an example of a LEED certified building?
The HOLT portfolio contains numerous projects that have obtained, or are registered and striving for, LEED Certification. An interesting private development is the Gateway Commons apartment project, which attained LEED Silver Certification.
The developer did not initially envision a project designed for sustainability, but through discussions with and urging from HOLT, agreed to pursue LEED certification. As the project progressed, the owner became increasingly involved in the process of striving for even higher sustainability goals.
As a starting point, the downtown site was a Brownfield redevelopment. Remediation required before construction could begin included removal of abandoned underground fuel tanks, in-ground hydraulic lifts, associated piping, and contaminated soils.
A major component of the sustainable strategies was to optimize energy performance. Energy efficiency measures include a high-performance building envelope, lighting occupancy sensors, high-efficiency boilers, central energy recovery for the mechanical ventilation system, and variable-speed circulating pumps. EnergyStar appliances were used throughout the apartments. The building energy modeling demonstrated annual energy savings of nearly 36 percent compared to conventional construction.
Another aspect of the sustainable design strategy was indoor environmental quality. Low-emitting materials were used to eliminate or greatly reduce the presence of volatile organic compounds (VOCs), and no products containing added formaldehyde were permitted. As part of the indoor air quality management plan, building ductwork and air systems were carefully protected against dust and contamination during construction, and the building underwent a two-week, high-volume flush-out prior to occupancy.
With the apartments renting at luxury rates for the area, the owner heavily emphasized the LEED Silver certification in successfully promoting the project.