Don't forget that LEED (following ASHRAE) uses energy cost and not straight energy when it compares your design to a base case. That's important because you might choose to use a system that burns natural gas instead of electricity and come out with a lower cost, even though the on-site energy usage in kBtus or kWhs is higher. Generally you have to specify the same fuel in your design case and in the base case, however, so you can't simply switch fuels to show a cost savings .
Design team members, including the architect and mechanical engineer at a minimum, need to work together to identify a percentage improvement goal for project energy use over the ASHRAE 90.1-2004-compliant baseline model. The percentage should be at least 14% (or 7% for existing buildings) to meet the prerequisite.
Contract an energy modeling team for the project. These services may be provided by the mechanical engineering firm on the design team or by an outside consultant. Software used for detailed energy use analysis and submitted for final LEED certification must be accepted by the regulatory authority with jurisdiction, and must comply with paragraph G2.2 of ASHRAE Standard 90.1-2004. Refer to Resources for a list of Department of Energy approved energy-analysis software that may be used for LEED projects.
Review case studies of similar energy-efficient buildings in the same climate to provide helpful hints for selecting energy-efficiency measures. For example, a building in a heating-dominated climate can often benefit from natural ventilation and free cooling during shoulder seasons. (See Resources for leading industry journals showcasing success stories around the country and internationally.)
Involving facilities staff in the design process can further inform key design decisions, helping ensure successful operation and low maintenance costs.
Load reduction requires coordinated efforts by all design members including the architect, lighting designer, interior designer, information-technology manager, and owner.
Use envelope design and passive strategies to reduce the heating and cooling loads prior to detailed design of HVAC systems. Passive strategies can reduce heating and cooling loads, giving the engineer more options, including smaller or innovative systems.
Select those strategies that are most suitable for your project type and location. For example, evaporative cooling is very effective in a hot, dry climate but is not likely to be a good idea in the cooler, damper Northeast or Northwest. The list is a good summary of the best ways to reduce energy intensity, though some strategies may be more effective in offices and museums, while others are more helpful in hospitals and hotels.
If you are installing a renewable energysystem that provides at least 5% of your electricity, you already implemented one of the three strategies from the Core Performance Guide.
