 |
|
|
Today, sustainably designed buildings are in the focus of building planning. For this purpose internationally different rating systems were established to make sustainability measurable. The U.S. Green Building Council published a procedure to measure the sustainability of buildings, called LEED (Leadership in Energy and Environmental Design), which is accepted worldwide and very widespread.
A point system that is easy to follow helps to make the abstract term of sustainability measureable. This evaluation system defines standards to be kept in the fields of site scheme, water consumption, energy consumption, protection of the Earth's atmosphere, use of building material, and interior design. The sustainability of the project is documented by a certification. Depending on the achieved number of points, as to the measured quality of sustainability, it is distinguished between four quality classifications (Certified, Silver, Gold and Platinum).
An overview on LEED assessment is given in the following short English summary:
LEED 2009 - New Constructions and Major Renovations
35 points alone can be achieved by a realization of measures in the field of energy cost minimizing and protection of the Earth's atmosphere. A central part in verifying energy optimization is the so-called Energy Performance Check. The Energy Performance Check specifies the forecast of the energy costs to be expected for the entire building. To determine the energy costs to be expected, the whole building has to be represented including planned systems and process technology with all energy relevant parameters and considering energy rates. For this purpose the method of integrated building and system simulation has to be applied, using a simulation program that is validated according to ANSI/ASHRAE standard 140-2004.
Similar to the procedure of providing evidence for the "Energy Performance Certificate" in Germany, the Energy Performance Check according to LEED compares the planned building to a reference building, which represents the minimum standard of energetic realization. In case of the Energy Performance Check, the quality of the minimum standard for buildings and systems has to be modeled according to the requirements of ASHRAE standard 90.1-2007. The used simulation program has to meet the ANSI/ASHRAE standard 140-2004.
The prerequisites for a LEED certification have to be proven by the obligatory Minimum Performance Check. Thus, a building cannot be certified according to LEED, until it achieves energy costs that are at least 10% lower than those of the reference building (according to ASHRAE).
In a second step, up to 19 assessment points can be collected for LEED certification (credits) within the Optimized Performance Check. Further assessment points (so-called ID credits – a kind of joker) can be collected, in case energy optimizations fall below the benchmark criteria for energy costs (>48% for new buildings, >44% for already existing buildings).
In a third step, with the On-Site Renewable Energy Performance Check, up to 7 assessment points can be gained for LEED certification (credits). Further assessment points (so-called ID credits –a kind of joker) can be collected, in case renewable energy supplies save even more energy costs than specified in the benchmark criteria (>13%).
The consulting engineers b+e offer consulting service for the Energy Performance Check. According to the individual task, we use the appropriate simulation programs (EQUEST, IES, TRNSYS) to optimize energy costs.
