Daniel Levy
Username
Daniel Levy
Proposer First Name
Daniel
Proposer Email
dlevy@greenspringbuilding.com
Proposer Last Name
Levy
Proposer Company/Organization
Greenspring Building, LLC
Proposer Phone
(410) 961-8900
Boston 2023 Areas of Focus
Proposed Session Description
Autoclaved aerated concrete (AAC), was developed in Sweden in 1923. It was designed as an alternative to wood--as easy to use without wood's limitations. This single product is load bearing, provides thermal and acoustic insulation, is more fireproof than concrete, isn't attacked by wood destroying insects, doesn't support mold, can get wet and dry without damage, and is airtight. Most surprisingly, it is a masonry that is readily cut with woodworking tools, and can be low in upfront carbon.
Diversity and Inclusiveness
I don't think this addresses the question, yet since AAC is common in most of the industrialized world it is used by all nationalities, religious groups, sexes, etc.
Learning Objectives
How is AAC produced?
How are AAC buildings constructed, both residential and commercial?
How can AAC meet the challenges of climate change?
What changes are on the horizon for AAC production and use in North America?
Has this session been presented before?
No
Additional Comments
I presented with Steve Bluestone on our earlier AAC work. We independently built the first two Phius certified homes built with AAC. We did not know each before we started our homes, and became friends. My new building, the "Bellwether on Main" duplex in Hillsdale NY, simplifies my previous work. The AAC walls are up to the second story lintels (11/1/2023); the building is not likely to be completed by March. Yet I think this is timely, and should not wait a year. I could include photos from the (finished) Woodstock house. I believe AAC provides the easiest way to build a Passive House, as it eliminates many steps involved in a wood-based building, while adding greatly to longevity.
Target Audiences Level of Expertise
Level 1 - No prior knowledge needed.
Session Format
Presentation followed by facilitated discussion or breakout groups
Session Format Details
Powerpoint talk, sample building products on hand, questions.
Recommended Length
60-minute session
90-minute session
Strongest Content Connection - Boston 2023
Comments about your speaker roster
Steve Bluestone and I have become friends, yet he isn't actively building now. We see each other almost daily; if he changes his mind about presenting I'd welcome his participation yet I can happily handle this alone.
Anything else you'd like to tell us about your session proposal?
I built an addition to a home I owned in Baltimore County MD in 1999 with AAC. At that time an 8" wall finished with plaster on the inside and stucco on the outside far exceeded the energy code for mass walls. I can't imagine a simpler construction system. Now in climate zone 5 (or 6 for Woodstock) I add exterior insulation; the performance is extraordinary. There are substitutes for cement, and AAC doesn't need builder grade sand. Yet even the Passive house community questions this, as they won't give up 8" of wall for only R 8.24 (standard AC4 density). But there is more than R value to a building, even a Passive building: this is airtight and impervious to most potential building failures. Forget most tapes, sealants, membranes, barriers, and almost everything else taught in Passive building sessions. AAC is inherently all control layers.
Reviewer 1
Widjaja, Karno
Proposal #
110
Committee Decision
Rejected
Full Description
Alex Wilson has written about autoclaved aerated concrete, and my work, as a potential answer to construction that can meet the challenge of climate change. An article he published in Vermont reached Europe, and he expanded it for a publication based in Germany: https://www.aac-worldwide.com/category/news/benefits-of-autoclaved-aerated-concrete-a-personal-experience-1823. Since building the Woodstock house, increased availability of products has enabled me to simplify this construction--specifically adding insulating stucco that is not a reservoir coating, and basalt rebar. Because AAC is 75 to 80% air, its up-front carbon impact is low for a masonry product by volume, and there are ways to further reduce its impact with ongoing worldwide efforts.