Digital Crayon: Article 10 – Greening Your Existing School Facility
by David Epstein, January 21, 2013
posted by David Epstein, AIA, LEED AP
In our last article, we discussed the sustainability in a general way as viewed through the lens of the LEED Green Building Rating System. I am sure many of you are wondering: how do I green my existing facility. Here again, looking at LEED’s Existing Building: Operations + Maintenance (EBOM) program is instructive.
As you might imagine, greening an existing facility is much harder than building a new one to green standards. For starters, the new construction program is a single event while the existing program is an ongoing process. This process includes changing the way you purchase materials, food, furniture and even how you clean the building. In short, it requires institutional behavior changes, which is often harder to do. And the EBOM system requires recertification every five years.
Many of the other credits in the EBOM system are similar to the new construction program: storm water control, water and energy efficiency, etc. But rather than speak in generalities, let’s drill down into a few topics to see how it works. First up: energy efficiency.
Our approach to making a new or existing structure energy efficient can be summarized in three steps. Step 1: Make the building envelope well-insulated and air-tight. This helps reduce loads on your heating and/or air-conditioning equipment, allowing them to be sized smaller. Next, specify energy- efficient equipment with options like heat-recovery and free-cooling. Third, is to specify smart controls. These include occupancy and CO2 sensors, dimming and multi-level lighting. The idea is to only run the lights and HVAC when you have to. Educating the users of each space to assist with these goals helps too!
Now some of these measures may cost additional money up front. The key to successful implementation of green design is to look at the life-cycle cost analysis of the proposed system. This is done by computing the energy costs of the proposed system vs. a baseline system and determining the when the energy savings have paid for the incremental cost difference of the upgrade. It’s always helpful to have a criteria (ex: 10 years) beforehand – just make sure is it shorter than the life of the equipment being considered!
Just as we discussed with new buildings, sustainability addresses much more than energy consumption. For example, a key quality of sustainable design is good indoor air quality. In an existing building, this can be improved in several ways.
The primary way is to ensure there is adequate fresh air ventilation of the space. This can be done with passively with operable windows or mechanically with ventilation equipment. Beware that the split system air conditioners, so popular for retro-fits, only recirculate air and do not provide fresh air. Indoor environmental quality can also be improved by using low-VOC paints, furnishings and finishes. Cleaning practices, too, should be examined to avoid using toxic chemicals or dust creating practices. Green Guard Environmental Institute (www.greenguard.org) certifies cleaning and other products as environmentally friendly and is accepted by LEED.
In addition to considering the VOCs (Volatile Organic Compounds) content in each product, the type and percentage of recycled content, location of origin and renewable nature of each choice must be considered to lower your school’s environmental footprint. Changing your purchasing selection criteria is an important way you can green your school – with or without a construction project.