Composite windows come in two basic types: fiberglass, and wood/plastic composite.

BuildingGreen-Approved Windows

Fiberglass and other composite window lines have NFRC unit U-factors of 0.20 or lower. Higher U-factors are allowed for products that include significant recycled content.

Manufacturers also must demonstrate... Read more

Welcome to the quiz portion of "The Potential of Prefab: How Modular Construction Can Be Green"!

Learning Objectives
Upon completing this course, participants will be able to:


I am forwarding this request from Kate Simonen from the Carbon Leadership Forum to support a grant application for this research. I don't know if the link will work in this format but if you have questions or want to sign you can contact me or Kate and I can send you the mail with the link my email is:  lstrain@siegelstrain.com     Thanks... Read more

Hello SD Leaders!

Two weeks ago a group of us gathered for the Winter 2020 Sustainable Design Leaders Summit. Those of us from BuildingGreen that were on site, greatly appreciated everyone's time and energy. It's always a pleasure to work along side you all!

Here is the summit report!

Reminder: We are giving a priority look... Read more

Hans “Grumpy” Grimm

Welcome to the quiz portion of The BuildingGreen Guide to Insulation!

Learning Objectives
Upon completing this course, participants will be able to:


I can hear Kjell saying "All models are wrong, but some are useful." Having said that we are having trouble getting usuable predictive energy use information from our electrical design engineer. They are telling us that their energy models are not for accurate pEUIs but just to compare various scenarios. Are they being lazy? Should we push for... Read more

I am excited to share with you the final draft of the letter back to LP50 manufacturers.  The LP50 manufacturers sent their “Closing the Loop on Product Transparency” to design firms earlier this year.  For more background information, please check out Chris Hellstern's original August 20th post on this Green Gurus forum.  When we posted the... Read more

The LBC v4.0 materials imperatives for Responsible Materials (Core) & Responsible Sourcing require a majority of wood materials (by cost) to be FSC. Sure. But what is - or isn't - considered wood? The Clarification page for the imperative's scope and a key definition poses a perplexing conundrum: 

"All wood included in the Materials... Read more

HI All,

Really hoping to get some insight from all you wonderful people on how the Sustainability teams are set-up in your construction companies. As mentioned in my introduction post, I am the first ever Sustainability Engineer hired by my company.....until now all the work was handled by project teams. Which worked for them in the... Read more

Mass Timber Construction: An Economic Study of Supply, Best Use, and Implementation in three North American regions

This series unveils a macroeconomic study of building with mass timber in three U.S. regions; the Upper Midwest, Rocky Mountain Colorado, and the Southeast. 

Three companies - SCB Architects, LeMessurier, and Turner... Read more

Do any of you have experience with Design For Freedom yet? It came to my attention and I'm trying to investigate. I would love to hear feedback and experiences that you may have at this point. It seems like an opportune moment for this issue of forced labor (yikes! so much I don't know...) to come to the forefront, and I'm curious to hear how... Read more

Hi Green Gurus,

We have a lot going on this week, and I know it’s hard to keep track of everything, so I’m providing this quick update.

Conveniently, we have also just launched the new Peer Networks Hub on BuildingGreen.com, with a Calendar page where you can see all upcoming events (and a link to recordings of past events). You... Read more

We have a project looking to use Radiant Floors to help with space heating.  I don't have experience with this so I'm looking for any insights.  Pros / Cons? 

This project is a non-profit and is needing to reach LEED Silver minimum.  This is in Washington State.  Thank you for your help.

CEUs are available for reading all the building-envelope product guides and primer. Click here to learn more and take the quiz.

Wall assemblies are made up of a number of different materials and systems, and installing each of them requires considerable time and labor and can introduce errors that compromise the building’s weather... Read more

Hi All,

Polling the group to see if anyone has experience with Simergy - an e+ based modeling tool?

The tool appears to have features and integration with a lot of e+ plugins that make it attractive - but i haven't heard of its widespread use.

Is anyone successfully using Simergy?

Hi SCL,

I realize that there are already a couple of threads on this topic, but I didn't see anything from the past year.  We have been trying (unsuccessfully) to work with large rental companies to request jobsite trailers that are at a minimum energy efficient, and ideally solar/battery ready and/or built to passive house or similar... Read more