Dan Thiede live-blogs this session at the Minnesota Green Communities third annual statewide GREEN BY DESIGN Conference. View all conference presentations here.
Presenters: Rick Carter and David Williams, LHB, Inc.
View the presentation from this session
LHB began researching and documenting actual performance data from projects in early 2007. Evaluation starts with energy use, greenhouse gas emissions, water use, and stormwater management. This session presents results from approximately 20 evaluated projects.
There are four main categories of Healthy House Guidlines that can be measured to determine building performace: (1) Site and stormwater management; (2) Energy efficiency and daylighting; (3) Resource efficiency; (4) Occupant health
Currently LHB mainly measures energy efficiency & daylighting, but are beginning to measure water use and stormwater rate, volume & quality, with plans to measure resource efficiency and occupant health in the future.
Rick and David identified a number of inititiatives from 1997 to 2007 that have contributed to bringing Sustainable Design to the forefront:
- AIA Top Ten Awards (of which LHB has won two: PEEC and Northland College)
- LEED
- Minnesota Sustainable Building Guidelines
- Minnesota Green Communities
- ENERGY STAR
- MN GreenStar Homes and Remodeling
Energy Use Metric
It is a challenging undertaking: condensing all of the energy types that are used and the units in which their use is recorded and condensing them into one metric—or one common language.
The metric LHB uses is kBtu/sqft/yr, or alternatively:
Energy Use Intensity=(E1+E2+E3)/Area.
The 2030 Challenge (visit Web site) is an undertaking to incrementally reduce the amount of fossil fuels consumed by buildings, starting with 50% today, by 10 percent every five years until 2030, arriving at net zero or better by that year. This means that by 2030 buildings will at the least produce as much energy as they consume. To make this a little easier, at any time 20% of reductions can be purchased. Here is what the reductions look like broken down:
- 50% today
- 60% 2010
- 70% 2015
- 80% 2020
- 90% 2025
- 100% 2030
These 2030 reduction goals, alongside average building performance by building type, is what LHB measures its projects against, and most of their projects meet—and even exceed—the 2030 goals. They have currently gone back and measured building performance in their buildings 15 years back and have numbers for their current buildings (totaling 75 measured projects), and have projected numbers for their projects in the planning stages. Here is a breakdown of their numbers for a few recent projects, in kBtu/sqft/yr (average for building type; 2030 goal; projected; actual performance):
- Quality Bicycle Products: 85; 52; 47; 42
- Two Harbors High School: 82; 52; 56; 56
- Al Loehr Veteran Apartments: 49; 30; 30; 25
- PEEC: 85; 52; none; 17.2
- St. Joan of Arc Church: 108; 65; none; 42
- New San Marco: 49; 30; 109; 25.11
Measuring Water & Stormwater… and Beyond
Water Use: Minnesota has not yet adopted any standards or limits for personal water use, but states on the west coast and in the southwest United States have had to do this already. A basic metric to go with is 30 gallons/person/day, and it is easy to measure the amount of water used by a building, divided by the number of people using the building.
Stormwater: When it comes to stormwater, rate, volume, and quality are the three main things that can be measured. It ends up that the most important one to measure for its impact is rate. Rate is measured in cubic feet/second, and can be measured where water leaves a site—thought it is not often measured yet. The Ramsey/Washington County Watershed offices are one building that collects detailed data on the rate, volume, and quality of the stormwater leaving their site—so it can be done.
Future Metrics:
- Waste
- Human health
- Materials
