2024 Award Winners and Nominees
Project Name
The Hope Center + Berkeley Way Apartments
Description
The Hope Center + Berkeley Way Apartments: First of its kind affordable housing nexus, integrating 4 affordable housing typologies into 2 buildings creating “a continuum of housing integrated into the fabric of the downtown community…a place to begin progress OUT of poverty and homelessness, projecting warmth, welcome, respect, and dignity”. Addressing both food and housing insecurity, this project demonstrates the commitment of the city and its non-profit partners to building a community based upon social, financial and environmental resilience.
The Hope Center includes a 32-bed men’s shelter, 12-bed transitional housing dorm for unhoused veterans, 53 permanent apartments, social and medical services, and a dining facility serving free daily meals to residents and the community. Berkeley Way Apartments provides 89 affordable apartments for low-income families (< 60% AMI). The design of both buildings was by Leddy Maytum Stacy for a unique partnership between BRIDGE Housing and Insight Housing created for this project. Since under resourced populations are most vulnerable to impacts of the climate emergency, this GreenPoints Platinum-rated project integrates a wide range of resilience, sustainability, universal design, wellness, and decarbonization strategies to provide safe, healthy, and resilient homes.
The structure, designed by Tipping Structural Engineers, comprises 4 stories of wood construction over two levels of prestressed concrete podium and a mat slab foundation. Approximately 4,000 cubic yards of concrete was used on the project overall. As part of a pilot project in the Bay Area Low-Carbon Concrete Codes Project, Arup supported the team as a technical advisor. Together, the team opted to specify cement content limits and sought to push for the lowest cement content possible from the start. The mixes provided by Central Concrete and approved by Tipping contain 55% less cement than national average concrete for the same strength. As a result, 680 metric tons CO2 equivalent of greenhouse gas emissions throughout the supply chain of the concrete were avoided compared to a national average.
The Hope Center + Berkeley Way Apartments was the first approved SB35 project in Berkeley. Integrated design strategies are essential to designing not just for the few, but for everyone.
Evidence
Key to the project success was initiating discussion with Nibbi Concrete, the concrete contractor, early on to find mixes that achieved lower cement content without cost increases or time delays. During design, the General Contractor, concrete supplier, structural engineer and pilot project consultant, Arup, met to analyze concrete mixes. They aimed for mixes with high cement replacements that would work structurally without adding significant time or cost. Working through the mix design requirements together before the GMP process was helpful and got the team on the same page about goals.
Construction brought a variety of time sensitive substitution requests regarding the concrete mixes. Some changes were due to seasonal fly ash shortages whereas others were to make the concrete pours simpler for the contractor. Fly ash shortages were dealt with by using mixes with slag only to replace cement instead of mixes with both fly ash and slag, which can have even lower cement. The design and construction teams discussed requests to modify the mix design to improve the concrete pours and found consensus on allowances that gave the contractor increased flexibility, particularly for the PT slabs, while still achieving high overall cement reduction targets. Throughout the submittal and substitution request process, the team needed to review the changes quickly, so the detailed tracking of the different mixes being used throughout different elements in the building was also essential.
Despite the hurdles, the team’s collaborative spirit, high ambitions, and pre-existing expertise led to its success. Notably, in December 2019, the City of Berkeley amended their building code to require concrete to include at least 25% substitute cementitious materials (SMCs) as a way to reduce carbon intensity. The Berkeley Way project was ahead of the curve and exceeded the code amendment before it came into effect, reaching 50-70% SCM content in many mixes.
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