This post originally appeared at The Conversation, and was co-authored by Jessica Heiges and Kate O’Neill. Most consumers don’t pay much attention to the packaging that their purchases come in, unless it’s hard to open or the item is really over-wrapped. But packaging accounts for about 28% of U.S. municipal solid waste. Only some 53% of it ends up in recycling bins, and even less is actually recycled: According to trade associations, at least 25% of materials collected for recycling in the U.S. are rejected and incinerated or sent to landfills instead. Local governments across the U.S. handle waste management,…

Warming temperatures have prompted changes in a climate-zone map used to set energy efficiency requirements across the U.S. The familiar multi-colored map showing seven temperature zones in the continental U.S. is published by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). It’s used by the International Code Council (ICC) to recommend requirements for insulation, windows, and other features in low-rise residential buildings. Acting on data related to a changing climate that has brought warmer conditions to much of the country, ASHRAE determined in 2013 that roughly 400 of the nation’s 3000 counties should be assigned to a new…

This article was originally published by the HVAC School; it has been slightly edited. It is the last in a three-part series. I am picking up where I left off in part 2 of the series, where I discussed how a pressure reading from an attached zone indicates only the ratio of the collective size of the leaks between the zone and the envelope with relation to the collective size of the leaks between the zone and outdoors (and vice versa). In other words, a zonal pressure diagnostic (ZPD) reading by itself does not tell us if a zone is…

You’ll probably hear the term “net-zero emissions” a lot over the coming weeks as government leaders and CEOs, under pressure, talk about how they’ll reduce their countries’ or businesses’ impact on climate change. Amazon, for example, just announced that more than 200 companies have now joined its Climate Pledge, committing to reach net-zero emissions by 2040. But what does net-zero emissions actually mean? “Zero emissions”—without the “net” caveat—means emitting no greenhouse gases. “Net-zero emissions” has more wiggle room. It’s like balancing a checkbook. The country or company cuts most of its emissions through efficiency and clean energy, then offsets the…

This episode of the BS* + Beer show features Gord Cooke, Mark LaLiberte, and Justin Wilson—the three principals of Denver-based Construction Instruction—explaining their approach to educating residential building professionals. They talk about the impetus for starting the program and dive deep into the value of experiential training, pointing to the efficacy of hands-on demonstrations—their primary teaching tool. They talk energetically about Ci Live, a turbo-charged, in-depth program covering applied building science, climate-specific construction, building enclosure details, HVAC mechanicals, drawing plan optimization, and more. If you care about building better homes and want to learn how to do it, watch this…

Builder-at-large Justin Fink is on the job with J&J Custom Builders to take a look at some unique roof framing. Here’s what he had to say about it. The flat section is just a big box joined by double LVL beams, with regular joists going down by blocking to stiffen everything up. In the corner, there are valley rafters for the hip roof that go all the way down to the wall plate. In all four corners, there’s a little birdsmouth at the top. You don’t need any posts here going down to the floor because all four corners are…