Proposal Status
Ready for Committee Review
Username
Christina Aßmann
Proposer First Name
Christina
Proposer Email
christina@passivetopositive.com
Proposer Last Name
Assmann
Proposer Phone
(315) 464-0049
Proposer Job Title
Senior Architect/Sustainability Consultant
Proposed Session Description
Combining Passive House and mass timber construction presents an opportunity to optimize both operational and embodied carbon. The exposed wood CLT structure and building envelope elements offer numerous benefits including: interior aesthetics, a healthier indoor environment, reduced use of interior finish materials, and shorter construction duration. However, to date, most CLT multifamily developments have been boutique condominium projects. Why? This session will feature two market-rate CLT Passive House multifamily projects that represent different design strategies for viability and carbon impact. We will analyze their similarities and differences, material and systems choices, design challenges and solutions, synergies and tradeoffs.
Why is this session important?
Mass timber has the remarkable potential as a carbon neutral alternative to steel and concrete construction. Passive House design focuses on cost effective design and strategies in reducing operational carbon. As the market and industry matures, mass timber and Passive House will show themselves to be essential tools in the overall effort to reduce the building industry’s carbon footprint. Correspondingly, many New England municipalities and the State of New York have recognized the twin benefits of Passive House and mass timber construction.
Maybe what is less understood is that the synergies between them yield benefits of each which may otherwise remain out of reach when implemented independently.
Despite the advantages, very few projects have been built using this winning combo to date. Clearly, significant barriers still exist. Cost, unfamiliarity, and uncertainty all play heavily into why forays into low carbon mass timber Passive House solutions often fail in the early stages.
Both of these teams began with a shared commitment to fact finding, reducing uncertainty, mitigating risk of the unknown, gaining confidence and finding innovative synergistic solutions.
Though the respective development teams didn’t realize it at the time, the synergies afforded by the combination of Passive House and mass timber design was the only way to make these high performing mass timber projects work from a cost and design standpoint.
Diversity and Inclusiveness
This session will include a diverse team of speakers and collaborators.
This presentation is not expressly about diversity, equity and inclusion issues, however our commitment to the use of Passive House and mass timber stems from our concern about the most universal threat to mankind and to life on the planet. In one sense this is the most democratizing and equalizing crisis in all of history. No-one will escape the impacts of this potential catastrophe. We are also mindful that it will most severely affect underserved communities.
Learning Objectives
Describe and evaluate the benefits of mass timber construction in relation to reducing a building’s overall carbon footprint.
Learn about the benefits of combining high performance building enclosures with mass timber construction.
Demonstrate how an integrated design approach can result in a successful project and how it helps with design implementation.
Explore the comparison of operational and embodied carbon.
Has this session been presented before?
No
Strongest Content Connection - NYC 2022
Anything else you'd like to tell us about your session proposal?
Description of the two featured projects:
79 King Street, Northampton, MA:
79 King Street will be a 110,000 SF building providing 66 rental units for people 55+, as well as ground floor retail and tenant amenity space. It is located in Northampton’s walkable downtown core, with easy access to local transit, Amtrak trains, and two major bicycle trails. The urban infill site is currently occupied by a single story, 5000 square foot building within a large parking lot. Due to code restrictions, the first floor and podium are concrete construction. The structure above consists of CLT floors over glulam columns and beams, and CLT shear walls. Exterior walls and cores are also CLT. To our knowledge, it is the first building for senior living in the US constructed of mass timber. Our research shows that approximately 80% of baby boomers cannot afford to age in place without the possibility of running out of money. The goal was to attract this demographic from suburban homes to urban apartments that fit their budget. The project just completed Schematic Design.
11 E Lenox, Roxbury, Boston, MA:
11 E Lenox is a 7 story, 34 unit apartment tower comprised of a glu-laminated post and beam structure with cross laminated timber floor slabs and FRT wood-frame exterior walls. Mass timber CLT proved to be advantageous in achieving unit density while staying within the 70 feet height limitations for mid-rise construction. At the time of design, the use of heavy timber for a structure was limited to five stories, and the architectural team received a variance from the state on the number of stories and concealed spaces. An integrated design approach and extensive Building Information Modeling (BIM) coordination contributed to a successful project outcome. The project has received Phius Precertification and is currently under construction. The project precedes the mass timber grant funding currently available for developments looking to pursue a mass timber alternative, and took full advantage of state funded MassSave energy incentives to fund the feasibility, development, and eventual execution of a Passive House Certified project.
A certain density was needed to make the costs pencil out for a mass timber superstructure (competing with light frame construction at lower density was not possible), and at that density, achieving it under 70ft (the MA limit for non-high rise construction).
Mass timber afforded the ability to stack 7 floors under 70 ft (9’-8” unit floor-to-floor elevations, with 8’-8” ceiling heights at exposed slabs and 7’-3” under beam thresholds). Passive House allowed for dramatically reduced systems which could fit within the limited floor to floor height.
Reviewer 1
Grant, Tristan
Committee Decision
Accepted
Round 1: MAYBE. The example
Round 1: MAYBE. The example projects are all in MA, I don't think this is a huge barrier, but wondering if this may be a better for a Boston Conference. I am interested in how these projects closed the "equity" gap by targeting a demographic that had difficulty affording long term senior living. It seems like an important point to highlight for the presentation