Retrofit

Five years ago, the capital city of Montpelier, Vermont, set a bold and audacious goal: for the city’s municipal buildings and operations to be Net Zero by 2030. What can a small city (under 7,000 people) with a volunteer energy committee do at the municipal scale? Come learn from Montpelier’s progress, challenges, and future plans.

This session will discuss the process of transforming an old masonry building in Newton MA into a PHIUS-certified net-zero office space and educational center for high-performance design and construction. The construction process will be discussed and Passive House features of the building will be described as will challenges and lessons learned from the process.

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?

This small New Hampshire town was faced with a host of issues with its 35,000 sf school. Key areas included IAQ problems, lack of temperature control, obsolete HVAC equipment, and high energy bills. A small group of volunteers proposed a radical solution: take one classroom as a prototype, disconnect it from the central plant, super-insulate it, and install a cold climate heat pump and an ERV.

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.

As architects, designers, builders, and community advocates, we value the adaptive reuse of buildings, but lack data to verify our design choices. We often operate on intuition to choose what to reuse and what to upgrade, attempting to balance life cycle impacts of new construction materials while lowering operational energy use. Over the last decade, Boston firms Bruner/Cott and Goody Clancy have evolved their practices in high-performance and transformative reuse to think more deeply about the embodied and operational impacts of reuse projects.

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.

As electrification grows as a tool to reach greenhouse-gas reduction goals, so do the risks of using electricity at times when it is most dirty and costly. To ensure that the benefits of long-term electrificaton of residential buildings are balanced with the short-term impacts on the grid, Massachusetts has begun testing consumer value propositions through tools like the 2017 Peak Demand Management Grant Program, Mass Save Connected Solutions, and the Clean Peak Standard.

Triple-decker homes, built in the late 19th and early 20th centuries to house immigrant workers, are an important New England housing resource. However, their energy performance is typically poor: they are often leaky, under-insulated, and heated with outdated fossil fuel systems. In this session, three organizations will describe scalable, replicable models to upgrade these iconic buildings. ABCD, which retrofits triple-deckers that house low-income individuals, will present on cost and energy savings achieved and challenges encountered.

This session will provide concrete tools and answers on how to draw down carbon in our buildings starting today. We’ll focus on low-rise buildings, where most new construction and renovations happen and which are currently under-represented in embodied-carbon design and analysis. We will present critical construction details such as band joist insulation selections and sloped ceiling retrofits, as well as whole-building design strategies.

Central ventilation systems in multifamily buildings are a vital building system with significant implications for energy, sustainability and occupant health and safety. In this session, we compare and contrast the building stock in Boston and NYC and explore a variety of techniques for restoring and improving these systems.

Urgent climate goals require state programs such as Mass Save to better target comprehensive decarbonization – applying efficiency, electrification, demand response, and solar+storage – in an equitable manner that addresses differences in local building characteristics. Meanwhile cities and towns, including low income/urban, suburban, and rural communities, are making commitments to local climate neutrality and social equity for their citizens.

Energiesprong and practitioners selected by RetrofitNY are developing standardized and scalable methods to achieve whole-building near-zero energy retrofits while maintaining multifamily tenants in place. Energiesprong, based in Europe, has successfully transformed 4,500 affordable units and RetrofitNY is currently in proof-of-concept phase.  The session will provide an introduction to standardized retrofits for multifamily housing, an overview of the best practices in Europe, and the practical implementation in the US market.

Should we be trying to electrify everything? Is it practical for existing and new buildings with the technologies we have now? Two engineers with different takes on these questions will debate electrifying residential buildings, from small single-family to high-rise apartments. Both speakers have years of experience with heat pump technologies (mini-splits, PTHPs, water-source HPs, VRF, and several types of heat-pump water heaters). They’ll present examples of buildings where these systems worked wonderfully, where performance was less than ideal, and a few absolute failures.