|By E. Mitchell Swann, PE, LEED
Well, actually I’m from Philadelphia – the home of good cheesesteaks and good lawyers (good engineers too!). But for the sake of this article, I join a growing segment of design and construction industry experts who are figuratively from Missouri when it comes to building performance. Missouri is known as the “Show Me” state. This means that you can’t just ‘talk the talk’ about some grand scheme or claim, you’ve got to ‘walk the walk’ – you’ve got to show me and prove it. “Show me” is becoming the de jour response to claims of superior “performance” by green or high-performance buildings. Owners, operators, tenants and even the design/construction community are looking for hard data and reliable metrics to verify claims of superior energy performance, low resource use, good indoor environmental quality and occupant comfort and satisfaction. This is a good thing.
Rating Systems, Design Guidance and Performance Measurement/Verification
The leading engineering technical society for energy efficient building design and indoor environments is ASHRAE3 . To address the growing issues associated with the quantitative design challenges presented by green buildings, ASHRAE in conjunction with the US Green Building Council (US GBC) and IES, has developed Standard 189 – Standard for the Design of High Performance, Green Buildings. What Std. 189 does is take the analytical approach to energy efficient building design first presented in ASHRAE Std. 90.1 (Energy Standard for Buildings Except Low-Rise Residential Buildings) and applied it (generally) to the categories defined in the USGBC’s LEED Program. So where both LEED and Green Globes are largely “aspirational” in nature (they set a goal but offer no method to get there), Std. 189 attempts to offer the technical guidance necessary to achieve those “aspirations.” ASHRAE Std. 189 gives you a map to help you reach your goals.
• Basic – Annual, “whole building” data; the results are indicative but not specific; includes energy and water use
• Intermediate – Monthly data; by major system; the results are “diagnostic’ and include thermal comfort and IAQ along with energy and water use;
• Advanced – Weekly/Daily/Hourly data analysis; system and equipment operational data; included lighting/daylighting and acoustics/vibration conditions.
Selecting the appropriate benchmarks is also key. The benchmarks are what you will compare your performance too and will inform the improvement objectives that you set. Targets that are too low will leave “money on the table” in that your facility might be capable of significantly better performance but since the bar is set so low, the operations team isn’t challenged to improve beyond that. Too high a benchmark will lead to a frustrating outcome as you find it nearly impossible to meet the goals. It can also cause you to allocate capital for improvements inefficiently as you unknowingly attempt to ‘overshoot’ what is ‘reasonable’ for your building. Selecting good benchmarks can be challenging but there are several independent databases that have aggregated energy and water use for a wide number of buildings and system types for both North America and the European Union.
So we will need the proper tools to assess the impact of operations and maintenance on overall sustainability; to observe, advise and alert operations when critical control parameters are heading out of bounds and to properly manage the business relationships that keep capital projects rolling in a way that achieves the objectives without crushing the participants.
Performance measurement and verification is here to stay
So what will we get? At the end of the day, we get better buildings: better in terms of resources, reliability, occupant satisfaction and long-term realized value. To get there we will find projects being done in a more collaborative manner, and this collaboration will blur some of the edges that have defined design and construction and operation for many years. And that blurring may create a different framework in which to view a “good job” and a “bad job,” who was to take care of what and to what standard should they be held.
1 LEED = Leadership in Energy and Environmental Design. It is a green building rating system developed by The US Green Building Council.
2 Green Globes = a green building rating system managed by the Green Building Initiative.
3 ASHRAE = The American Society of Heating, Refrigeration and Air-Conditioning Engineers
4 CIBSE = Chartered Institute of Building Services Engineers (UK Technical association)