Page 143 - Designing for Zero Carbon-Volume 2_Case Studies of All-Electric Multifamily Residential Buildings

OBSERVATIONS DESIGNING FOR ZERO CARBON, VOL. 2
carried out, usually by a commissioning agent hired by the owner, the performance of all systems can be verified for the post-occupancy period.
Energy efficiency and optimal solar PV system performance will still be high operational priorities in our decarbonized building future, both for individual owners and public utility operators. Systematic metering will help ensure this.
• Affordability, Now More than Ever
For multifamily housing in California, particularly affordable housing for low-income tenants, the issues of construction and operating cost have become critical issues. In response, state and some local governments have taken steps to revise zoning laws to expedite projects and reduce pre-construction costs for developers and non-profit builders. Cost and affordability, as well as marketability (in the case of multifamily units for sale) were key issues in all of the multifamily case studies in this book. In all cases, the all-electric design solutions proved to be the most cost-effective compared to the conventional designs with both gas and electric systems. (See the discussion in Case Study No. 5 – Casa Adelante at 2060 Folsom, p. 108, for a cost analysis of all-electric versus gas-plus-electric design for several multifamily projects.)
What’s New and Evolving
Since the publication of Volume 1 of Designing for Zero Carbon in March 2022, there has been continued development of analytical software tools as well as continued improvement in building technologies and their deployment in multifamily projects.
• An Eye on Embodied Carbon
When the goal of a decarbonized public utility grid in California is realized in approxi- mately 25 years, every all-electric building will operate with zero-carbon emissions—a great eventuality. For building designers, there is also an evolving concern with the importance of embodied carbon, since carbon emissions will still result from the manu- facture and transport of construction materials of all types.
There has been a rapidly-developing understanding that this issue can and should be addressed during the design phase of the project. The analytical tools have advanced to the point that they are included in the regular design software and projects can read- ily be studied for embodied carbon content. Materials specified can be identified as “hot spots” of embodied carbon and replaced, minimizing the project’s overall embodied car- bon content. (See the discussion in Case Study No. 5 – Casa Adelante at 2060 Folsom, p.110 and p.111.) Such studies, made feasible only with the recent advances in design software, can make the evaluation of embodied carbon in projects a routine exercise.
• Developing Building Technologies and Energy in Housing
Each of the five case studies in this volume demonstrates creative new approaches to the design of all-electric heating, cooling and domestic hot water systems. While these systems are based on heat pump technology, the solutions are varied appropriately for the size and type of multifamily project. The design solutions can be readily adapted to similar projects.
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