Archive for the ‘Certification’ Category
The Passive House in the Woods received the highest Minnesota GreenStar® certification (Gold) today. We are very excited to see the certification come through and congratulate the owner and all the team members involved in the design and construction on this achievement!
We used the Minnesota GreenStar® program to compliment the Passive House certification. It’s green markers helped track resource efficiency, indoor environmental quality, water conservation, and reduced site and community impact, with the energy efficiency requirement being met and exceeded by the achievement of the Passive House certification.
We received the certificate from PHIUS today. The Passive House in the Woods is now officially a Quality Approved Passive House.
Here is a quick list of it’s key performance data in reference to Passive House limits:
- Heating Load: 10.6 kWh per m2 living area and year [3.36 kBTU/ft2yr]
(limit: 15 kWh or 4.75 kBTU); about 30% less than allowed
- Air Tightness: 0.25 ACH50 in reference to the building’s volume
(limit: 0.6 ACH50); almost 60% better than allowed
- Source Energy Consumption: 106 kWh per m2 living area and year [33.6 kBTU/ft2yr]
(limit: 120 kWh or 38.05 kBTU)*
- CO2 Emissions: 16.5 kg per m2 living area and year;
CO2 Emissions avoided with solar PV system: 16.9 kg per m2 living area and year.
Therefore the building becomes CO2 neutral for operation.
*) The design was made for a 2 person household, which lowers this number to 65 kWh, or 20.6 kBTU
Calculations are based on the Passive House Planning Package 2007 model.
Gary Nelson from the Energy Conservatory was gracious enough to perform the final blower door test today. We used the Minneapolis blower door with a duct-blaster and Tectite Software—following the PHIUS protocol and the DIN EN 13829 norm. The house performed better than during the rough-in test, which was to be expected since added finishes and completed window assemblies add to the tightness of the home.
The averaged result: 68 CFM50 leakage, or 0.25 ACH50.
Both blower door tests have been a fun learning experience for the team and a big success, since the house performed remarkably better than the Passive House limit of 0.6 ACH50.
For those who think in CFM leakage numbers, the house averaged 70CFM—75 depressurized (0.28 ACH50), and 60 pressurized (0.22 ACH50). For those who could care less 😉 this is a really, really tight house.
Upon completion, the Passive House in the Woods will be earning certification from MN GreenStar. MN GreenStar is a green building program that was developed to address the unique building conditions that exist in a cold climate region. The program sets the standard for sustainable design and construction in Minnesota and western Wisconsin, so through certification, the Passive House in the Woods will be documented as a leader in green building.
MN GreenStar uses a checklist to determine the certification level: Bronze, Silver, or Gold. The certification level is based on the number of points the project earns. The Passive House in the Woods is projected to earn a Gold certification, the highest level possible. The checklist system of MN GreenStar allows the builder to examine individual components of the project across all areas of construction throughout the construction process.
There are several challenges with using the MN GreenStar program for the Passive House in the Woods. Some construction methods and components critical to passive house design can not be accurately accounted for in the HERS Index, a performance rating system used with the MN GreenStar program. Also, those same construction methods and components are not all included in the program’s checklist, and in fact, are actually better then items in the checklist. The MN GreenStar program, however, does provide an opportunity to earn points not captured by the checklist through the submittal of a proposal for innovation points. It is our hope that MN GreenStar will recognize these challenges and help inform the content of the checklist as the program continues to develop and improve.
In using the MN GreenStar program, both the client and the builder benefit. The documentation required by the certification process provides verification that the house is constructed to the standard MN GreenStar sets for green building. The checklist format is easily comprehendible by the client and encourages their involvement in the building process. The checklist can also inform the client in decisions they are responsible for making. In the case of the Passive House in the Woods, the checklist has helped the client select finishes, appliances, and water fixtures.
In certifying the Passive House in the Woods by a holistic green building program like MN GreenStar, the opportunity to examine the construction process and building techniques is created. The program not only strongly encourages and promotes sustainable design and construction, but ultimately makes for a better way to build.
Amanda Spice is a project developer at Morr Construction.