SPONSORED BY MASS CEC - Massachusetts will need an “all hands on deck” approach to achieve net zero emissions by 2050. For its 2+ million existing buildings, this will require significant efficiency improvements and full electrification.  However, the current rate of building transitions is a fraction of what is needed due in part to low consumer awareness, system design/integration challenges, and inherently complicated consumer decisions.

This is a tale of two companies on a quest to account for the embodied carbon impacts of energy retrofits, and to incorporate these impacts into the project planning process. How do we decide when embodied emissions are worth longer-term emission reductions? What are the pros and cons of choosing lower embodied carbon materials compared to higher emission ones?

Builders and developers, whether public or private, can learn from the success of Columbia County NY Habitat for Humanity, which uses Passive House methods to provide high-quality, healthy, and affordable housing. Key lessons include strategic site planning, envelope assemblies and details friendly to unskilled labor, and keeping to budget while coping with design changes, building code variations, fluctuating costs and availability of materials, and evolving Passive House standards.

Join the growing community of radically responsible industry stewards using Hempcrete, a bio-composite material created from the woody core of the hemp plant combined with a lime-based binder. Trusted around the world as a robust, high-performance sustainable building system, HempLime entered the US market a decade ago and is poised to take the industry by storm. Delve into design and construction details and review the specifics of costs, source material supply, and obtaining building approval from officials.

Back in 2016, our team started a multiyear experiment, sponsored by Building America, on unvented roofs without spray foam or exterior rigid insulation, using an instrumented test hut with multiple test bays. The experiment examined cellulose vs. fiberglass insulation, interior vapor control membranes, diffusion vents at the ridge, interior humidification, inward vapor drive issues, and the effect of air barrier imperfections. Some preliminary results were presented at BuildingEnergy Boston in early 2018. After three winters of experimentation, this is the rest of the story.

States across the region are setting ambitious heat pump targets to support their climate goals. But what will it look like to retrofit millions of homes with heat pumps as the primary heat source? This session explores efforts in Massachusetts to answer that question with applicable lessons for the entire region. In 2019, Mass Save launched a first-in-the-nation incentive for integrated controls that automatically transition between heat pumps and traditional heating systems.

What have we learned about the experience of living in a deep energy renovated home? Come hear 3 pioneers in the deep energy renovation space talk about what it was like to create and now live in a zero net energy (ZNE) renovated home. We've got data, we've got lessons learned, and we'll illuminate the human experience of living in a home that creates more energy than it uses on a net annual basis. The existing housing stock is where the vast majority of residential energy and carbon savings potential exists.

From retrofitting a ranch built in the ’40s to conditioning massive multi-family Passive House developments, air source heat pumps are being selected as the primary method to heat and cool an ever-growing variety of housing stock. While this technology is remarkable in its affordability, efficiency, and ability to offset a major contributor to greenhouse gas emissions, there are often unmet challenges in selecting the most appropriate piece of equipment.

Maine Passive House (MPH) has used two different strategies in retrofitting existing homes. One strategy involves adding insulation to the outside of the building; the other strategy is to add insulation to the inside of the building. Most projects involve a mix of the two strategies. Along with added insulation and eliminating thermal bridging, MPH increases air tightness, installs high performing windows and doors, and adds mechanical ventilation systems in their projects.

Come hear the results of the “Grid of the Future” pilot program, which offered Maine homeowners a discount on smart appliances (heat pumps, water heaters, smart EV chargers, and batteries) in exchange for allowing aggregated remote control of those devices as a “Virtual Peaker” power plant. The virtual power plant was controlled to demonstrate the potential value of aggregated, controllable distributed energy resources including reducing the need for fossil-fuel peaker plants, reducing transmission costs, and enabling deeper penetration of renewable energy on the regional grid.