What impact does window selection have on energy efficiency and sustainability?  What factors influence the energy performance of windows?  Populus Sustainable Design Consulting and SolarGlass Window & Door presented on these issues at last year’s USGBC Colorado Sustainability Conference.  Here is a description of that presentation:

The session will explain the implication of the DOE’s pending 2009 Energy Star changes for high altitude markets and review the product design responses planned by leading manufacturers.  Additionally, the session will discuss the interplay of the following factors on building envelop efficiency, sustainability, and occupant comfort: glazing to floor area ratios, dispersion of windows by elevation, glazing alternatives, frame materials, the often overlooked importance of quality installation

Attendees will come away with an understanding of what design elements should be given priority when developing a window solution for a given project, as well as the trade-offs associated with aesthetic, performance, and price considerations.

Included in the presentation will be an overview of the growing importance of performance-based measurements of building envelop efficiency (e.g.; Resnet’s Home Energy Rater modeling software) and how windows impact the HERS score.

USGBC Colorado has recently posted Populus & SolarGlass’s “Sustainable Window Selection” presentation on its website.  Of particular interest, on page 11 of the presentation, you will find a graph which demonstrates the specific concerns and trade-offs related to window selection for various ranges of desired HERS Index Scores.  Pages 13-18 contain a case study which analyzes the interaction of window selection and mechanical systems as it relates to home energy performance.

Populus is a full service sustainable design consulting firm that focuses on high performance, net-zero and near-net-zero custom residential and multi-family projects.  Populus guides architects and builders through the requirements of mandatory green building codes and optional green home certification programs, providing HERS rating, LEED for Homes Green Rater services and LEED for Homes training.  Visit Populus at www.popboulder.com.

Shoes lined the sidewalk at the Logan Wiggins House on the Center for Resource Conservation’s Green & Solar Homes Tour last Saturday, September 26th in Boulder, Colorado.

A full house of shoeless visitors learn about zero energy homes and greenbuilding at the Logan Wiggins House

The tour was hosted by homeowners Jim Logan (of Jim Logan Architects) and Sherry Wiggins.  The home was sponsored on the CRC’s Solar & Green Home Tour by Populus Sustainable Design Consulting, who provided the energy modeling and LEED for Homes Green Rater services on the home.  The all-electric home, which goes beyond net zero and beyond carbon neutral, was inspired by Logan’s effort to reduce his carbon footprint to a level that would be sustainable for the planet.  With a negative HERS Index score, the Logan Wiggins Home generates enough additional electricity to charge a plug-in electric vehicle.

David Neiger of Populus explains the energy efficient features of this zero energy home

David Neiger of Populus spent the day in the jam-packed mechanical room explaining the high-performance and green features of this net zero Boulder home.  David taught visitors about building science and the workings of heat-recovery ventilation and ground source heat pumps, while Mike Vail of Water Legacy highlighted the home’s graywater system.

Erik Warner of Namaste Solar was also on-site during the tour, answering questions about the 9.9 kw photovoltaic array on the home.  Namaste Solar provided the grid-tied PV System for the home, while Aircraft installed the Earthlinked Technologies ground source heat pump.  The home also incorporates Serious Materials’ (formerly Alpen) triple pane double Heat Mirror windows.

Populus is a full service sustainable design consulting firm that focuses on high performance, net-zero and near-net-zero custom residential and multi-family projects.  Populus guides architects and builders through the requirements of mandatory green building codes and optional green home certification programs, providing HERS rating, LEED for Homes Green Rater services and LEED for Homes training.  Visit Populus at www.popboulder.com.

The Department of Energy came to Denver this week, promoting its Builders Challenge initiative, which seeks to promote affordable, zero energy homes for all Americans by 2030.  Ed Pollock, the Residential Team Leader for the U.S. Department of Energy hosted the Builders Challenge tour at the EEBA Conference which featured two homes, including Sean Smith & Co.’s Wash Park Green LEED Certified Duplex in Denver’s Washington Park neighborhood and Ecofuture’s Solar Harvest House in Boulder.

Ed Pollock of the U.S. Department of Energy promotes the Builders Challenge alongside David Neiger and Laura Hutchings of Populus and Sean Smith of Sean Smith & Company (seen here in Builders Challenge-inspired t-shirts)

David Neiger, Principal at Populus Sustainable Design Consulting, led the EEBA conference tour through the high-performance energy features of the Wash Park duplex, which scored a 37 on the Builders Challenge E-Scale.  The E-Scale, which is a “miles per gallon” type rating for a home, is tied to the Home Energy Rating System Index Score, and denotes how the home performs compared to a typical home built to code.  A home must score below a 70 on the Builders Challenge E-Scale to be eligible for certification under the Department of Energy’s program.  In addition, the Builders Challenge program requires the implementation of greenbuilding best practices which address indoor air quality and durability management.

Following the Builders Challenge Tour, the Populus team joined Ed Pollock, Sean Smith, Eric Doub of Ecofutures and Tom Wade of Artistic Homes at a panel discussion focusing on zero energy homes and the goals of the Builders Challenge / Building America program.  Mr. Pollock began the panel presentation by discussing the Department of Energy’s Builders Challenge goal of an affordable zero energy home (or “Net Zero”) for all Americans by the year 2030.  In order to achieve these substantial increases in residential energy efficiency, it is essential that the building industry highlight the operational savings of a zero energy home, rather than merely focusing on the first costs of high-performance home features.

David Neiger of Populus presents to a group of industry professionals at the Department of Energy Builders Challenge EEBA Conference Home Tour

To date, the Builders Challenge program has certified a total of 1800 homes, with six homes scoring net zero or better on the E-Scale and with an average E-Scale score of 63.  While this represents only a tiny fraction of the homes built in the United States each year, the high-performance energy features of these 1800 homes results in an average cost savings of $1.6 million per year.

If you are a builder, developer or architect and would like to learn how you can pursue Builders Challenge certification for your next project, contact Populus Sustainable Design Consulting, a Partner in the Builders Challenge program, and we’ll walk you through the program requirements and the steps to certification.  Unlike some green home certification programs, there is no fee for registering your project in the Builders Challenge program, although there are costs associated with the third-party verification and energy rating that is required under the program.  In some cases, building an above-code performing home can qualify you for substantial rebates, incentives or tax credits.

Populus is a full service sustainable design consulting firm that focuses on high performance, net-zero and near-net-zero custom residential and multi-family projects.  Populus guides architects and builders through the requirements of mandatory green building codes and optional green home certification programs, providing HERS rating, LEED for Homes Green Rater services and LEED for Homes training.  Visit Populus at www.popboulder.com.

Last night the Boulder Green Building Guild (“BGBG”) went beyond carbon neutral at its Building On-Site Seminar (“BOSS”), featuring the Logan Wiggins House 3.

Jim Logan Presents the Logan Wiggins Residence at BGBG's Building On-site Seminar

The event was hosted by Jim Logan (of Jim Logan Architects) and Sherry Wiggins.  The all-electric home, which goes beyond net zero and beyond carbon neutral, was inspired by Logan’s effort to reduce his carbon footprint to a level that would be sustainable for the planet.  With a negative HERS Index score, the Logan Wiggins Home generates enough additional electricity to charge a plug-in electric vehicle.  In addition to describing the high-performance green features of the home, Logan discussed the home’s aesthetic inspiration, which was envisioned as a “box of light.”

The evening included networking, dinner by Sublime Catering and feedback from a panel of experts that included Doug Parker, Sustainability Examiner Boulder County, Craig Christensen, Principal, Engineer at NREL and Ron Flax, Associate and Project Manager at Rodwin Architecture.  The Logan Wiggins House 3 will be featured on the CRC’s upcoming Solar and Green Home Tour on Saturday, September 26th.

Populus is a full service sustainable design consulting firm that focuses on high performance, net-zero and near-net-zero custom residential and multi-family projects.  Populus guides architects and builders through the requirements of mandatory green building codes and optional green home certification programs, providing HERS rating, LEED for Homes Green Rater services and LEED for Homes training.  Visit Populus at www.popboulder.com.

Ready to go beyond carbon neutral?  Register now for the BGBG’s September 23rd Building On-Site Seminar at Jim Logan’s beyond-net-zero, carbon neutral “Logan Wiggins House 3.”

Logan Wiggins House 3 goes beyond net-zero in its bid to achieve LEED for Homes Platinum certification.

The home, designed by Jim Logan Architects and built by Hughes Construction, is pursuing LEED Platinum certification in the USGBC’s LEED for Homes Rating System.  With its super high performance energy features, it looks as though this project may end up being the highest scoring LEED Platinum project in the country to date. 

Populus Sustainable Design Consulting provided HERS energy modeling and rating services, as well as LEED for Homes Green Rater services on the project. 

This beyond-net-zero home utilizes an Earthlinked Technologies refrigerant-based ground-source heat pump with a forced-air delivery system.

Namaste Solar, also a Boulder-based company, provided the grid-tied PV System for the home, while Aircraft installed the Earthlinked Technologies ground source heat pump.  The home also incorporates Serious Materials’ (formerly Alpen) triple pane double Heat Mirror windows.

Interested in learning more about the green features of this beyond net-zero, carbon neutral home?  Join us for the BGBG’s Building On-Site Seminar or visit the home during the Center for ReSource Conservation’s Tour of Solar and Green Homes on Saturday, September 26th.

See Inside a Lifebreath Heat Recovery Ventilator ("HRV")

Populus is the exclusive sponsor of the Logan Wiggins House 3 on the CRC’s tour and will be on-site during the day to answer your questions regarding the green, high-performance features of the home.

Populus is a full service sustainable design consulting firm that focuses on high performance, net-zero and near-net-zero custom residential and multi-family projects.  Populus guides architects and builders through the requirements of mandatory green building codes and optional green home certification programs, providing HERS rating, LEED for Homes Green Rater services and LEED for Homes training.  Visit Populus at www.popboulder.com.