Wednesday, February 20, 2008

Measuring the Forest and the Trees. Or, How Green is Our Valley?

As you no doubt know by now, it's important to us that this project have as little impact on the environment as it can and yet still be within the realm of achievement for the average family - who may not be as eco-geeky as we are but are interested in doing as much as they can. It's pretty easy to make claims about environmental stewardship and responsibility and quite another to carry them out. How do we measure our success? How do we quantify our energy efficiency and environmental performance?

First, this is important to us so we spend a great deal of time researching materials and systems and choosing the ones that are both environmentally preferable and economically viable. We don't do the things we can't afford - but this doesn't mean taking the least expensive option on the table. Rather, we look at the environmental and economic balanced value of our choices. We're willing to pay more for high performance windows, insulation and equipment because we know that it will reduce our long term maintenance and energy costs. The savings we garner from lower utility bills will pay for those very slight upfront costs many times over during the life of the home. In order to determine this we need to look at the lifecycle of the material or system, its performance and cost. We've hired the Neighborhood Energy Connection ( to do an energy model. This helps determine what our expected energy load and performance will be - based on our design and materials and systems selection. We can play around with variables during the design and determine the approach with the best return for our investment, and the least environmental impact. At the end of construction - we'll test and commission the systems to make sure they perform up to expectations. It's a balancing act. Because we plan on owning this home for a long time, we have no problem accepting paybacks as long as 20 -30 years on some items. But most of the things we're doing offer paybacks of 6 years or less. We'll monitor our performance and energy bills on an ongoing basis to ensure top notch performance as well.

Our decisions are not driven by paybacks alone. Sometimes you just have to do what's right. For instance, there is no significant economic payback for using less water or for using no VOC paints, etc. But it's the right thing to do. Also, looking at the results of our energy model alone, tells us that we really only needed to use triple glazed windows on the north side of the house. But, the energy model software doesn't really account for all conditions equally, and experience tells us that triple glazed windows make sense and will provide better comfort - so, that's what we're doing.

We are also getting an objective 3rd party to validate our claims. We're in the pilot phase of a design guideline and rating system called the Minnesota Greenstar Program ( There are a number of great guidelines out there - Green Home Guide (, ReGreen, Built Green, LEED for Homes (developed by the U.S. Green Building Council) and many more. We selected the Minnesota Greenstar Program for many reasons. First, it's a guideline that is designed to be applicable to the microclimate in our cold climate as it features regional strategies that make sense here in Minnesota - rather than Florida. Different climate, different needs. Unlike LEED and other guidleines, the Greenstar program is specific to remodeling projects and contains different Tiers and requirements based on the actual scope of the remodeling project. It's a point based system with specific prescriptive requirements and options within each of the tiers. You collect points based on the strategies implemented (proof of achievement required) and at the end of the day your project gets a rating of Bronze, Silver or Gold in ascending order. We're expecting to achieve a very high Gold rating. Even though some of the documentation is cumbersome (it has a 47 page checklist!) we like the fact that it requires a holistic approach to design and implementation. It addresses everything from plant species used on site, water and energy efficiency, waste reduction, material use, indoor air quality, lighting, and equipment selections.

The LEED guideline (and others) are organized in a similar fashion, but are geared more toward new construction (ReGreen being the exception). LEED can be used on remodels but effectively requires that you strip everything down to the studs and start over in order to achieve the energy ratings required. That's simply not feasible on most remodeling projects - and Greenstar accounts for the variety of remodeling projects one might undertake and partners that with strategies appropriate for our region and microclimate. Yippee!

In the end, we'll have a measurement of our "green" achievements that can withstand scrutiny and the burden of proof. We'll know if we diverted 71% of of construction and demolition debris from the landfill or 77%. We'll know how much energy we're supposed to use and how much we actually use. Our claims will have weight and merit and will be a good baseline against which other projects might measure themselves and hopefully surpass our achievements!

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