From the outside, it looks like a house. A well-designed one. Quietly modern, nothing performative. The difference is what you don’t see, but will definitely feel.

Heating is the largest form of energy consumption in a typical New England home. A superinsulated, airtight building enclosure - the walls, windows, doors, foundation, and roof - can be used as a passive strategy to reduce the heating energy required. In other words, the 'passive' in Passive House means the design does the work. A Passive House prioritizes:

• Insulation → a continuous thermal 'jacket' to slow heat loss

• Airtightness → no uncomfortable drafts or energy waste and improved durability

• Fresh air ventilation → consistent, healthy indoor environment for your family

• High performance windows → triple pane windows allow for warmer indoor temperatures and provide extra noise reduction

• Design + orientation → siting to optimize solar heat gain 
  
  

The result is a home that requires a fraction of the heating and cooling energy, along with incredible thermal comfort, healthy indoor air, and a peaceful interior environment. It’s a smarter way to build, especially in cold climates.

If you’re thinking about building or renovating, these decisions matter most before the walls go up.

More on Passive House principles.

ASHRAE's Center of Excellence for Building Decarbonization website defines building decarbonization as “methods that reduce human-made GHG [Greenhouse Gas] emissions related to buildings.” These GHG or carbon emissions of buildings are made up of both building operations carbon emissions - primarily the use of energy to heat, cool, light and otherwise power buildings. They also represent the embodied carbon inherent in the building construction, use and end-of-life (from raw materials extraction, transport, installation, through the building use and demolition, deconstruction, recycling or landfill disposal.)

Whenever decarbonization-focused renovations of existing buildings are considered, a question is undoubtedly posed (sometimes earlier, sometimes later in the process): Is demolition of poor-performing buildings and replacement with new construction a more worthwhile investment? The financial term “ROI” is occasionally raised and applied to buildings and other built environments, while less readily measurable values are ignored. Values such as the social and emotional capital of families remaining in their homes, or the pride of maintaining a stable home for someone formerly unhoused, are challenging to monetize and are, consequently, disregarded in a return-on-investment calculation. The reader could insert any number of anecdotal housing stories here, which would further enrich the context surrounding the question of housing value. 

However complex the question of value, Residential Property Owners are nonetheless charged with making reasonable and informed decisions regarding continued or capital investments in their properties. Those decisions must be made year after year. For Affordable Housing and Public Housing Owners, especially during times of uncertain funding and market volatility, these decisions require Owners to have expansive and deep Operations and Maintenance knowledge, to weigh MANY factors, and, in this writer’s opinion, to display great courage. Why courage? Because Owners rightly continue to protect their property investments in the face of uncertainty, and because the answer to the question, “Is investing in Decarbonization of an Existing Building worth it?” is almost always, annoyingly, “yes, however….” This is how companies like ZeroEnergy Design end up doing decarbonization feasibility studies and why we continue to advocate for custom and project-specific design solutions. The truthful and inconvenient response to whether it’s worth saving existing buildings is yes, however the amount of reasonable investment depends on any number of factors.

One factor is the building’s use. We want to focus on residential buildings, in particular Affordable Housing and public housing, a dedicated focus of ZeroEnergy Design, because (1) Community Resilience depends first and foremost on people having access to safe and healthy shelter, (2) As a state, region, and nation, we are currently experiencing a housing crisis (1) where many already do not have secure or affordable housing (meaning affordable to a vast array of incomes), and (3) Climate change is raising the threat of residential displacement across the country due to coastal or riverine flooding, increased precipitation, or wildlands and urban/suburban fires. Add to the equation the ethical imperative to provide equitable and decent housing for individuals who are low-income, under-housed, or historically marginalized, and renovations of federal- or state-funded and maintained properties become all the more critical. In our opinion, the immense societal and resiliency NEED for stable and healthy residential buildings, especially at this point in time, increases the value of investing in “decarb retrofits” of this particular building type.

The value of any renovation also depends on other factors:

• The condition of the existing buildings and their systems, including whether they have been maintained or have extensive deferred maintenance;

• The necessity of preserving prior investments or other property assets, such as accessible unit conversions, window replacements, or hazardous material remediation (which may have required capital campaigns in the recent past);

• The suitability of the originally-designed building for its current and future use. Adaptive reuse aside, think how much smaller homes and room interiors were in the new construction of post-WWII America, or how sprawling, many-roomed Victorian homes were, compared with contemporary homes, which usually center a kitchen / family room reflecting today’s lifestyles;

• Location and Site Context - How will construction sequencing, staging, and logistics be implemented? Are the required utilities available at the site, or must infrastructure be developed and utility service be brought to the site? How do municipal regulations affect the project costs?

• Soft costs other than design, such as permitting, community outreach, and resident relocation costs;

• Whether the existing use and scale are the best long-term use for the property. With the high cost of both renovations and new construction, the team should consider whether the property could reasonably be redeveloped with increased density, thereby furthering the Owner’s mission to house more people. 

These evaluations are important calculations for Owners to make prior to undertaking a major renovation. 

Unless conducting a renovation by replacing “in-kind” (meaning replacing existing building systems to the original performance specification at the time of installation), our experience of retrofitting existing residential buildings in Massachusetts is that building costs are often, but not always, comparable to ground-up construction. Due to the older building stock found in the Northeast, replacing “in-kind” may include obsolete or substandard materials and systems, which do not represent professional best practices and are not recommended. In-kind replacement may no longer be an acceptable, healthy, safe or code-compliant solution. 

While the value of decarbonization retrofits of existing buildings has broad support across the high-performance design and construction community, the question of how extensive an intervention to make is hotly debated and evolving among professionals (see Byggmeister’s “Our Evolving Approach to Energy Retrofits”). Some practitioners advocate for abandoning or demolishing poor-performing buildings, some advocate for all existing buildings to be brought up to current new construction standards (this would represent best practice for the long-term continued use of the property), and some advocate for a “good enough” approach (fixing only certain aspects of the construction). Our professional opinion falls primarily in the second camp when the budget allows, with concessions considered acceptable where necessary for not doing the maximum intervention to meet project goals and budgets. The crux of the argument for renovation over new construction is that the embodied carbon of existing structures, as well as the embodied carbon of new structures/materials, can significantly increase or reduce GHG emissions generated by a project. Therefore, we generally advocate for decarbonization retrofits as a means of reducing construction and operational emissions. 

In a New Construction project or renovation with a healthy budget, our approach is (1) to invest maximally in a well-detailed, highly-insulated envelope, (2) to install right-sized, efficient and balanced mechanical systems, and (3) to offset site energy use with renewable energy systems - generally Photovoltaics for their market availability and pricepoint.

In a Decarbonization Retrofit on a limited budget, our approach is more nuanced: we advocate for maximum emissions reductions within the project budget, without introducing unreasonable amounts of embodied carbon. Taking into account unique or special project considerations, the project priorities are developed based on the Owner’s or Community’s goals, and seek to identify and avoid any intervention which might result in diminishing returns. We also prioritize preserving and prolonging the life of the building(s) to the greatest extent possible. All-electric operations, or strategic electrification/decoupling from fossil fuel, is our first priority for any renovation, for both environmental and human health and safety reasons. We endeavor to further inform the Owner by outlining the costs of intervention as well as the known and unknown costs of inaction.  Using the established project priorities and our quality-focused standard practice, we develop a custom approach for each project.

The costs of intervention are the sum of hard and soft costs typically associated with a design and construction project, as well as the inconvenience to the residents and the property owner.

The costs of inaction include environmental degradation and economic inefficiency; most of us can think of examples where deferred maintenance or repairs led to higher costs later. There are also quantifiable social equity impacts. The housing shortage can be exacerbated if existing buildings are not maintained and become untenable for human habitation. The State Strategic Housing Plan notes the state’s public housing system has an estimated $4 billion backlog of capital improvements; additionally, 6,000 units of privately-owned affordable housing are at risk of conversion to market rate before 2027 (2). These statistics help explain why Protecting Existing Homes and Affordability is the second of five strategies in the State’s Strategic Housing Plan (3). When routine maintenance is deferred year after year, eventually buildings and their systems fail and limited funds must be spent on repairs rather than capital investment. This complicates both the financing and construction logistics of renovations, making decarbonization investments even more challenging. Every public housing development we have studied or for which we proposed an intervention has some deferred maintenance in a variety of areas and to differing degrees. 

In a recent decarb feasibility study for a large 1950 masonry family development, we identified a significant economic benefit of renovation over new construction using the Carbon Avoided Retrofit Estimator (4) (CARE) Tool. In the same study, another cost of inaction we monetized was construction cost escalation. Sadly, many projects remain unfunded or underfunded because they are too expensive now, yet the cost increases at the next funding cycle, and again the next. 

There are MANY more existing homes than new being built at any point in time in our communities. This fact should tell us that preserving housing in healthy, well-functioning order should be the priority for owners, government leaders, and industry practitioners. Today’s decent, healthy, well-functioning housing must produce minimal emissions if they are to continue to meet human needs into the future. Therefore, we encourage owners of low income and affordable housing to prioritize the social, emotional, and health benefits that decarbonization renovations provide residents and the wider community when they calculate the benefits versus costs of continued property investment. 

Footnotes:

1) Refer to “Executive Summary: Understanding and Tackling Massachusett’s Housing Challenge” from A Home for Everyone (February, 2025) for an overview of this complex problem, available at https://www.mass.gov/doc/a-home-for-everyone/download

2) Refer to p. 20 of A Home for Everyone (February, 2025), available at https://www.mass.gov/doc/a-home-for-everyone/download 

3) Refer to p. 29-31 of A Home for Everyone.

4) The CARE Tool is an open source tool for the building sector used for estimating and comparing the embodied, operating, and avoided carbon impacts and benefits of reusing and upgrading existing buildings or replacing them with new construction. It is an Architecture 2030 project, developed by Larry Strain of Siegel & Strain Architects, Lori Feriss of Goody Clancy, and Erin McDade of Architecture 2030, with input from the Zero Net Carbon Collaboration, the Climate Heritage Network, the Carbon Leadership Forum, and Epic, among others.

We’re honored that Providence Net Zero has been awarded a Gold Medal for Best Single Family Detached Home (6,000–8,000 SF) at the 2025 PRISM Awards!

This Providence home blends classic New England charm with modern, sustainable innovations. Sun-filled spaces invite reading, writing, and gathering, while thoughtful glazing connects the interiors to the lush, landscaped yard. The design fosters a unique “urban family compound,” linking nearby relatives through adjoining gardens and shared outdoor spaces. Wrapped in renewable cork insulation and powered by solar energy, the home achieves carbon-neutral comfort without fossil fuels. A green roof, spa, and beautifully designed patios complete this urban oasis balancing warmth, efficiency, and a deep connection to nature.

We are grateful to the incredible team that collaborated on this project and to BRAGB for this recognition!

Architecture & Mechanical Design: ZED

Contractor: Adams + Beasley Associates

Landscape Architecture: Greg Lombardi Design

Interior Design: Atsu Gunther Design

Photographer: Nat Rea Photography

ZED is proud to announce that Stow Passive House gained Phius ZERO Certification, a major accomplishment that represents the highest standard of energy performance and carbon accountability in building design and construction. In addition, we earned a 2025 Phius Passive Projects Design Competition Award! The rest of the winners are listed here.

These accomplishments celebrate our team’s commitment to design excellence, sustainability, and innovation in high-performance architecture. They also reflect the dedication and collaboration of our entire team in advancing architecture that is both timeless and transformative, particularly our collaborative contractor, Star Contracting Co., who did an incredible job building this home.

About Passive House Certification: earning certification means this project is designed and tested to perform well above and beyond other buildings when it comes to comfort, efficiency, resilience and safety. Projects certified to Phius’ climate-specific, cost-optimized standard are proven to use 40-60 percent less energy and provide a comfortable living environment.

In an extensive spread, ZED’s Providence Net Zero project was featured in the July-August 2025 issue of New England Home. The striking net‑positive, all-electric home on Providence’s historic East Side beautifully marries sustainable performance with modern New England style. The home presents a familiar façade of cedar shingles and stone steps, while the rear elevation reveals contemporary flair with a charred-wood cube clad in shou sugi ban and large operable windows opening to landscaped gardens and solar power above.

Inside, high-performance systems - including cork and cellulose insulation, triple-glazed windows, solar photovoltaics, and heat-pump HVAC - enable exceptional energy efficiency while delivering abundant daylight, clean air ventilation, and durable materials with low environmental impact. The thoughtful program includes indoor–outdoor rooms, a family studio suite, green roof, and an intimate garden plan, creating comfort, wellness, and a timeless aesthetic rooted in New England vernacular.

ARTICLE LINKS: WEB VERSION | DIGITAL MAGAZINE

TEAM:

Architecture & Mechanical Design: ZED

Contractor: Adams + Beasley Associates

Landscape Architecture: Greg Lombardi Design

Interior Design: Atsu Gunther Design

Photographer: Nat Rea Photography

In a city like Boston, where historic streets meet modern challenges like traffic congestion and rising emissions, the bicycle has become more than just a recreational option, it’s a vehicle for environmental change. As architects, we actively design for bikes, too. In cities like Somerville, there are requirements for dedicated bicycle parking in new residential projects, but even in areas without formal regulations, we at ZED often incorporate thoughtful bike storage solutions. Whether it’s a secure garage, dedicated indoor area, or weather-protected exterior space, designing with bikes in mind reflects a commitment to healthier, more resilient communities.

Zero Emissions, Maximum Impact. Whether you're coasting down the streets of Belmont or navigating the protected lanes on Mass Ave, each trip made by bike is a small but meaningful act of climate action. Bicycles produce no emissions, making them one of the cleanest modes of transport available. In Boston, where the average car commuter spends hours stuck in traffic each week, switching to a bike even a few days a week can drastically reduce your carbon footprint. According to MassBike, trips under 3 miles — perfect for biking — make up a significant portion of daily travel. Choosing bikes over gas powered vehicles helps reduce greenhouse gases, air pollution, and our dependence on fossil fuels.

More Than Just Clean Air. Beyond emissions, bikes take up less space and require fewer resources to manufacture and maintain. Twenty bikes can fit in a single parking spot — great news for Boston’s notoriously limited parking options. Expanding bike infrastructure means fewer paved lots, better stormwater management, and more green space. When you bike, you’re also reducing wear and tear on city streets, which cuts down on costly maintenance and construction.

Health on Two Wheels. Biking doesn’t just help the planet — it helps your body and mind. Studies show that people who commute by bike enjoy better cardiovascular health, improved mental well-being, and increased energy. Boston’s increasingly connected bike network makes it easier than ever to incorporate physical activity into your daily routine—without setting foot in a gym. From reducing the risk of chronic diseases to lowering stress levels, hopping on a bike is one of the simplest ways to boost personal health while also cutting emissions.

E-Bikes: A Worthy Middle Ground. Not ready to power your commute solely with pedal power? E-bikes are gaining traction across Boston as a viable, lower-impact alternative to cars. While not emission-free (due to battery production and electricity usage), e-bikes dramatically reduce greenhouse gases compared to cars and make longer or hillier commutes more accessible — especially helpful in a city with neighborhoods as varied as Jamaica Plain and Beacon Hill. They’re a particularly smart solution for those who might otherwise avoid biking due to physical limitations, long distances, or lack of time. As the City of Boston continues to expand its infrastructure with programs like Bluebikes and dedicated e-bike parking, it's clear that both bikes and e-bikes have a critical role to play in shaping a more sustainable, accessible urban future.

Let’s Ride, Boston. From the Emerald Necklace paths to the densely populated neighborhoods like Davis Square in Somerville, Boston offers an expanding network of scenic, functional routes for biking. Making the shift to two wheels—whether pedal or electric—means fewer cars on the road, cleaner air in our lungs, and a city that works better for everyone. So grab your helmet, pump those tires, and let’s make Boston better—one ride at a time.

Background on the project: A fire severely damaged a triple-decker on Columbia Street in Cambridge, displacing three low-income families. The Cambridge Community Housing Development (CCHD) collaborated with ZED to renovate the building with a focus on sustainability and energy efficiency. The renovation included installing air-source heat pumps for heating and cooling, energy recovery ventilators for continuous fresh air, and dense-packed cellulose insulation made from recycled materials. Notably, the original residents were able to return to their homes post-renovation, highlighting the project's success in combining affordable housing with sustainable living.

Bluedot Living Article

The series is produced by Harbor Media in partnership with the Hingham Municipal Lighting Plant (HMLP) and the Hingham Climate Action Commission (HCAC), highlighting Hingham’s transition to a Net Zero future. Later episodes in the series are expected to include information about incentive programs and other resources to help residents.

The debut episode introduces viewers to the concept of Net Zero, the Town’s Climate Action Plan, and what a Net Zero home can look like. Host Brianna Bennett, HMLP’s Sustainability Coordinator, speaks with HCAC members about the Town’s goals and tours a local Net Zero home with homeowner Deborah Smith and Stephanie Horowitz, Managing Director of ZeroEnergy Design.

“The Hingham Power Hour is about making electrification tangible so everyone can feel empowered to go Net Zero,” said Bennett.

“The Town of Hingham voted to be Net Zero by 2040, and this series showcases the innovation and collaboration happening to realize that goal.”

Watch the video below (ZED interview at minute 34:50)

Senior Project Manager John Mucciarone, seen above in his natural habitat sketching on a napkin over a beer in Portland, ME. On this particular occasion, John was part of a gathering of architects and designers for a 'Drink + Sketch,' covered in Maine Home Design magazine. Local architects from the Portland area were invited to gather at Novare Res Bier Café in Portland for a drink and to celebrate the hand-drawn in an increasingly digital world.

Participants created sketches inspired by prompts like designing a downtown Portland train station, a structure based on a favorite board game, a children's play fort/treehouse, an adaptive reuse for an old space, or a reimagined Adirondack chair. John’s submission was titled “Treehouse: an elevated, urban escape in nature that is simple, playful, and imaginative for the inner child in all of us.”

Read Full MH+D Article

Mt. Hope Modern, a coastal home in Portsmouth, Rhode Island, was one of the featured homes in the Houzz Article, titled ‘8 Coastal Homes with Awesome Ocean Views.’

Located in the coastal neighborhood of Bristol Ferry/Common Fence Point, Rhode Island with a commanding ocean view, this seaside modern home welcomes you to its warm stylish interiors, while just as quickly shifting your gaze towards the sea. The fenestration creates a variety of views and experiences, all intended to capture natural light and ocean vistas. 

READ THE ARTICLE

Two of ZED’s multifamily affordable housing projects in Cambridge, MA - Porter Road Apartments and Columbia Street Apartments - recently gained Enterprise Green Communities certification! This certification program aims to promote the creation of sustainable, healthy, and environmentally responsible affordable housing.

The Enterprise Green Communities Certification is a comprehensive green building framework designed specifically for affordable housing developments in the United States. Gaining certification can be challenging, as it requires comprehensive adherence to a set of rigorous standards that cover various aspects of building design, construction and operation. Here are some key aspects of the certification:

1. Holistic Approach: The certification addresses various aspects of building and community design, including energy efficiency, water conservation, indoor air quality, and the use of eco-friendly materials.

2. Criteria for Certification: Projects seeking certification must meet specific criteria that cover integrative design, location and neighborhood fabric, site improvements, water conservation, energy efficiency, materials beneficial to the environment, healthy living environment, and operations, maintenance, and resident engagement.

3. Benefit for Residents: The primary goal is to improve the health and well-being of low-income residents while reducing environmental impacts and operating costs.

4. Application and Process: Developers of affordable housing projects must adhere to the certification standards from the planning stages through construction and operation to achieve certification. The process involves planning, implementing, documenting, and reviewing strategies that meet the certification criteria.

5. Support and Resources: Enterprise provides various resources, including guidelines, case studies, and tools, to assist developers in understanding and meeting the certification requirements.

This certification plays a crucial role in promoting sustainability in the sector of affordable housing, ensuring that these benefits reach communities that often have fewer resources to invest in sustainable development.

To learn more, check out the Enterprise website.

The evolution of the workplace, particularly with the rise of remote work, has brought about a renewed focus on the aesthetics of our work environments, extending beyond the physical office to include the digital realm. Having a beautiful office is no longer just about creating a pleasing physical space for productivity and creativity; it's equally important to consider the visual backdrop that represents us in virtual meetings. This dual focus ensures that our professionalism and attention to detail are evident, not just in our work, but also in the environments we choose to display during video calls.

Creating a net zero sustainable home was the first priority for our client in Somerville, MA - a gorgeous office and zoom backdrop was just the cherry on top. The ascending staircase of bookshelves, paired with the cascade of ornate pendant lights and lush greenery conveys a strong sense of the owner’s identity. Moreover, the window-laden office itself contributes to a positive work-from-home experience overall, boosting mood, creativity and productivity. In a time when the boundaries between home and work are increasingly blurred, a dedicated and aesthetically pleasing workspace can help create a sense of routine and normalcy. It can also serve as a form of personal expression, allowing individuals to showcase their style and preferences in a way that enhances their work identity.

A Modern Mid-Century Home in Belmont

This modern high performance home in Belmont was built in two phases, beginning with an addition to an existing 1960s-era house. The home’s two bifurcated wings informed the decision to phase the project so that the owners could live in part of the home with their three children during construction. The design kept a similar footprint and created two distinct wings with a connector in between. This central corridor is the home’s formal entry point and provides a dramatic perspective overlooking the abutting Mass Audubon sanctuary beyond.

Inside or out, this home blends and flows into its surroundings, outfitted with large glass doors, generous windows and oversized sliders at several key connection points. The triple glazed Schucco windows and doors allow wonderful views regardless of the season. ZeroEnergy Design (ZED) carefully framed views of the outdoors from each space of the home, taking advantage of the scenic conservation areas and gardens surrounding it.

In keeping with the Passive House principles, the home is incredibly energy efficient with a Predicted Energy Use Intensity (pEUI) of 3.5kBtu/sf/yr. The super insulated envelope has a concrete slab has 4” of EPS below with an R-value of 17. The above grade walls are R-44 and the roof is R-66. The home’s air tightness exceeds .05cfm/ft2, which measures the air leakage in relation to the surface area of the building envelope. For context a typical new construction is about 3 ACH50 or less. This home tested about six times tighter than that - at 0.37 ACH50.

To optimize thermal comfort, state-of-the-art Zehnder ERVs supply all the living spaces with filtered fresh air year round. This feature enables recovery of 90% of the energy from the conditioned air as the stale interior air is exhausted out. The ERV, combined with the exterior insulation on the walls and roof, significantly reduces the energy needed to heat and cool the home.

All of the home’s appliances are electric. Mitsubishi heat pumps supply the heating and cooling; electric induction cooktop and laundry facilities take care of the cooking and cleaning and electric heat pump water heaters take care of the rest. 42 Roof-top mounted solar panels keep the electricity running and supply a powerwall for emergency back-up.

ZEN Associates worked with the architects and clients to seamlessly integrate the indoor and outdoor spaces with expansive views and oversized sliding doors. We worked to protect existing mature plantings around the home and the new plantings enhance the modern aesthetic of the home.  The use of native plants and thoughtful design brings the outdoors-in creating an organic feel to the new spaces. An interesting story from the build is that during excavation, an underground stream was discovered at the foundation level. We were able to divert it around the house and guide the natural water flow out over boulders from the excavated areas to the wetland in the backyard.

PROJECT TEAM:

ZeroEnergy Design
Architecture & Mechanical Design

Auburndale Builders
Contractor

ZEN Associates
Landscape Architecture and Construction

Montage
Furnishings

Nat Rea Photography
Photographer

MORE: Case Study

On Friday May 19th, ZED joined Northeast Sustainable Energy Association (NESEA) in leading a BuildingEnergy ProTour of a 3-unit triple decker in Cambridge that underwent a gut rehab after a fire in 2020. The project was developed by Homeowners Rehab Inc (HRI) and now provides three apartments for low-income residents.

Erika DeRoche of ZED kicked off the tour with a 45-minute overview of the project, which was then followed by a three-stage tour of the basement, exterior, and interior of one unit. Erika DeRoche from ZED, Deliandro Cruz of Alpha Smart Builders and Nate Wickman of New Ecology, Inc. hosted each station, talking about the finer points of this ambitious energy efficient renovation. Attendees were able to hear about design decisions around HVAC, Domestic Hot Water and Fire Protection systems, as well as the wall and flooring assemblies, all of which prioritized resident comfort and sustainability.

We are incredibly proud of this project and the work of all of our partners and collaborators that made it come together so successfully. Our hope is that this type of retrofit - all-electric, no combustion on site, high efficiency systems and super-insulated envelope - will serve as an example of not only what is possible for this building typology, but also what should become the norm for future projects.

Learn more about this project: Columbia Street Residences

More images from the tour here.

ZED’s Acton Passive House was featured on NBC Boston, providing an inside look at the benefits of a net zero, Passive House Certified home. The piece includes interviews with ZED’s Stephanie Horowitz, Contractor Adams & Beasley’s Dave Wittig, and Owner Philippe Lam.

Take a look at the video that gives an overview of the home’s many high performance features, such as rooftop solar panels that produce more energy than it uses over the course of a year, making it net positive energy. The environmental benefits to the owner include remarkable thermal comfort, excellent indoor air quality, low operational cost, a durable, long-lasting structure, low embodied carbon materials, and most importantly, a happy client enjoying his beautiful new home.

LINK TO STORY

Houzz spoke with 12 pros about which sustainable features homeowners should consider to cut energy use and reduce their carbon footprint. Architects, builders, interior designers and landscape designers were interviewed and also discussed the sustainability solutions they’re most excited about.

ZED’s Jordan Goldman, provided the following thoughts:

Sustainable features ZED uses. “Our main focus for sustainability is reducing the carbon footprint of our buildings. [That applies to] both operational carbon — due to the energy demand — and the embodied carbon — due to the materials involved in the project’s construction,” Jordan Goldman says.

“To reduce operational carbon, we emphasize an exceptionally well-insulated envelope, efficient systems and renewable energy.” Goldman says. “To reduce embodied carbon, we try to avoid or minimize the use of materials like concrete, steel and foam, since they typically have an outsized contribution to the overall embodied carbon. To reduce both operational and embodied carbon, we avoid designing oversized houses and buildings.”

Sustainable solutions Jordan’s excited about. “Over the last couple of years, we’ve shifted from using rigid foam [insulation] to products like wood fiberboard — made from compressed sawdust, diverting the material from the waste stream — and rigid cork — made from harvesting cork trees in a process that doesn’t harm the rest of the tree. Both products are considered to be carbon storers — that is, negative embodied carbon — so they’re much more environmentally friendly than rigid foam, which has significant embodied carbon,” Goldman says.

FULL ARTICLE

Location: Inman Square, Cambridge, Massachusetts

Services: PHIUS+ Energy Consulting and Mechanical Design for a New Modern Single Family Home

ZED recently visited a site in Cambridge to check out the progress of the home’s air barrier. ZED’s Jordan Goldman, who provided energy consulting and mechanical design for the three-story, single family house, led the site visit along with representatives from ZRE Development (Owner) and GRS Construction (Framer). Site visits like this during construction are important both for catching any errors before the building enclosure is complete and for educating builders about proper technique going forward in the process.

Jordan walked the interior and exterior of the home, paying particular attention to the many tricky areas where air leakage typically occurs. A home’s air barrier is intended to limit uncontrolled air leakage into and out of a building’s thermal envelope. ZED’s design is for the air barrier to be continuous, which means that the system has no discontinuities, particularly as it transitions from one assembly to another (e.g. from wall to roof). ZED typically installs the air barrier at the sheathing layer, where it’s easy to maintain continuity across the envelope. Exterior rigid insulation will protect the air barrier from the outside and the framed wall cavity protects the air barrier from meddling hands on the inside.

Example of an air barrier:

Thermal Envelope:
The basement slab, foundation walls, above-grade walls, ceilings, roofs and any other building element assemblies that enclose conditioned space or provide a boundary between conditioned space and outdoors or uninsulated spaces.

The largest component of this Cambridge home’s air barrier is the green ZIP System sheathing that wraps the whole exterior of the house, but there are other components that we will explore below: