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MassCEC Pilot Showcases Success of Whole Home Heat Pumps

Location: Massachusetts
Type of home: Various
When first built: Various
When last renovated: Various

Heat pumps can serve as a whole-home heating and cooling solution in Massachusetts. That was the primary takeaway of MassCEC’s Whole-Home Heat Pump Pilot, which ran from May 2019 through June 2021. And whole-home heat pumps will be fundamental to the Commonwealth meeting our goal of one million households using high-efficiency electric heating systems by 2030.

Whole-home heat pumps are essentially heat pumps that serve 100% of a building’s heating needs. While heat pumps are increasingly common in Massachusetts, many are supplementary to fossil fuel heating systems in homes. However, as the state increasingly electrifies its buildings, more and more will rely on heat pumps for all of their heating needs.

Whole-home heat pumps offer many benefits. First, they deliver a comprehensive heating and cooling solution that serves the whole house, increasing comfort and convenience. Second, they do not require homeowners to maintain and operate two separate heating systems. This eliminates the need to maintain fossil fuel pipes or tanks and keeps the homeowner from needing to maintain and potentially replace a second heating system in their home. And last, whole-home heat pumps deliver superior emissions reductions and will continue to get cleaner as the state’s electricity transitions toward being carbon free.

MassCEC’s pilot worked to demonstrate that whole-home heat pump systems offer a high-performance solution today and that the market is ready for significant expansion going forward.


Background on the Whole Home Heat Pump Pilot Program

MassCEC launched the Whole Home Heat Pump pilot shortly after ending our larger Residential Air-Source Heat Pump Program, which had run from November 2014 through March 2019 and supported the installation of air-source heat pumps at over 20,000 homes. In January 2019, Mass Save® expanded its incentives for supplemental air-source heat pumps – at least for customers switching from oil, propane, and electric resistance. This allowed MassCEC to shift its focus to demonstrating the benefits of whole home air-source heat pumps.

In order to ensure that supplemental heat pumps are being used for heating and to access their higher incentives, Mass Save® requires oil and propane customers switching to heat pumps to either install integrated controls that operate both their heat pumps and their fossil fuel system or remove their fossil fuel system. When Mass Save® launched their incentive, they discouraged the removal of the backup system due to concerns about customer comfort at the coldest temperatures, but they recently removed this language, reflecting growing acceptance of the ability of cold-climate heat pumps to serve as a stand-alone heating solution.

A major goal of MassCEC’s pilot was to demonstrate that heat pumps can be stand-alone solutions, so hopefully our pilot has helped contribute to acceptance of this approach as another option for customers along with integrated controls depending on the customer’s situation and goals. MassCEC also hoped that the pilot would surface cost-effective and efficient design strategies for whole-home air-source heat pump solutions. Some of these cost-effective projects are highlighted in the case studies below.


Awarded Funds under the Whole Home Heat Pump Pilot Program

The MassCEC pilot offered a flat incentive of $2,500 per home for existing homes that were switching from natural gas to whole-home heat pumps or new construction/gut rehab homes that had whole-home heat pumps and had no fossil fuel appliances in the home. In order not to overlap with Mass Save incentives, the MassCEC pilot was only open to residents that heated with natural gas (and were therefore not eligible for the higher Mass Save® incentives). Based on current fuel prices, customers heating with natural gas have the lowest value proposition for switching to heat pumps, but MassCEC knew that there were residents interested in making this transition, and we wanted to support these projects while gathering project data that could be used to inform future state programs and policies. The MassCEC pilot offered higher incentives for income-qualified customers and, towards the end of the pilot, MassCEC created an adder for projects that included other efficiency or electrification measures as part of the heat pump project.

In the two years that we ran the pilot, we awarded funds to 168 whole-home heat pump projects: 31 new construction projects and 137 retrofit projects (including 11 gut rehabs). About a quarter of the projects either received an income-based adder for low and moderate income homeowners or were affordable housing projects. A total of 39 installers participated in the pilot.


Lessons Learned

The primary lesson learned is that whole-home heat pumps are a feasible solution, not only for new construction, but also for retrofitting existing buildings, including older homes. See the case studies linked below for stories of homeowners who have been heating their homes with heat pumps. We surveyed pilot customers six months after project completion, and 95% of respondents were somewhat or fully satisfied with the level of comfort for heating, while all were somewhat or fully satisfied with the level of comfort for cooling. We encourage homeowners thinking about whole-home heat pumps to start with making their home as efficient as possible. Tighter homes can install smaller and/or less heat pump equipment, will be more comfortable, and will have lower operating costs. A no-cost Mass Save® Home Energy Assessment is a great place to start if you live in Mass Save® territory. Homeowners across the state can refer to MassCEC’s Weatherization Checklist.


Costs for Whole Home Heat Pump Solutions

Costs were higher than we hoped. As shown in the table below, median project costs for the pilot were $18,400. We saw less expensive costs for new construction projects versus retrofits, probably largely because new construction homes had smaller loads so they could install smaller/less heat pump equipment. Also, the heat pump equipment could be designed with the house from the beginning instead of retrofitted. For retrofits, some of the more affordable projects that we saw were for projects that could reuse existing ductwork and/or had smaller homes without a lot of small rooms. Some of those projects are described in the case studies below. Our hope is that costs for whole-home heat pumps projects will go down, as installers become more comfortable with the capabilities of heat pumps and manufacturers offer more options. However, because heat pump technology is relatively mature worldwide I do not expect to see the rapid price declines that solar photovoltaic projects have seen (although I hope I’m wrong!), so I expect that incentives will continue to be necessary to achieve the state’s electrification goals, especially for low and moderate income homeowners.

Whole-home heat pump projects can be complicated and require an installer who is comfortable with the approach. Of the retrofit projects in our pilot, 25% required an electric service upgrade, while 38% reported that their natural gas heating system also provided their domestic hot water, which meant that homeowners either had to leave their natural gas boiler in place just to heat their hot water or else buy a new hot water heater as part of the project. In the pilot, we heard many anecdotes from homeowners who were the main champions for a whole home heat pump solution and sometimes faced hesitation from installers, but our hope is that over time installers become more comfortable navigating and promoting whole-home heat pump projects. Some of the contractors participating in our pilot do have the level of experience to confidently recommend and design a whole-home approach. If you are considering a whole-home project, ask your installer about their experience and comfort with a whole-home scenario. Our Questions to Ask Your Air-Source Heat Pump Installer article has a list of questions that homeowners can ask when they are considering getting heat pumps.

In reviewing the applications, we almost never had a question about whether a system was sized adequately to heat the home; installers tend to be conservative on this front (for good reasons!). Instead, we often were pushing installers to consider sizing down equipment so that heat pump systems would not be over-sized. For ductless projects, our technical consultant (Bruce Harley), often recommended multiple outdoor units and especially single-head units (one outdoor unit connected to one indoor unit) for less cycling and more efficient operation. Sometimes, homeowners still preferred multi-head units due to lack of space for outdoor units. Ducted units can be an economical solution if a home already has ductwork, but if new ductwork needs to be built ducted projects tend to get more expensive. Compact ducted units can be a good solution for serving several small rooms.


Case Studies

MassCEC has put together profiles of several whole-home heat pump projects where the homeowner has lived with the system for at least part of a winter:

As an aside, I am putting my money where my mouth is on the issue of air-source heat pumps. At the end of last winter, my oil tank sprung a leak. It was going to be $3,000 to replace the oil tank, so that was the push my family needed to get heat pumps and remove the oil heating system. Because I was heating with oil, I was able to take advantage of the Mass Save® rebates. While I have not lived through a full winter with the heat pumps yet, it’s been great to have better cooling in the summer, and we’ve enjoyed the extra space with the oil tank removed from the basement and the radiators removed from the rooms.


Next Steps

MassCEC has the flexibility to pilot new technologies or innovative applications of technologies, like whole-home heat pumps, but we do not have the budget to scale these approaches to the mass market. So as MassCEC wraps up the Whole-Home Air-Source Heat Pump Pilot, we are excited to see what entities like Mass Save® will do to promote whole-home electrification options on a broader scale. Recently, Mass Save® has begun supporting air-to-water heat pumps and ground-source heat pumps. All signs indicate that heat pumps will be a major focus of Mass Save’s three year plan for 2022-2024. In particular, it’s great to see enhanced incentives for moderate-income households in Mass Save’s draft three year plan, since, as discussed above, whole-home heat pumps continue to have high upfront costs. For MassCEC, our next step in residential decarbonization will be launching our Decarbonization Pathways pilot. The Decarbonization Pathways pilot will build on the lessons of the Whole-Home Air-Source Heat Pump Pilot and offer more comprehensive support and coaching to homeowners and better integrate other efficiency, electrification, and renewable opportunities with heat pump projects.

Additionally, MassCEC has contributed some funding along with NYSERDA and the foundation E4TheFuture for a study that The Cadmus Group is conducting on the future of residential cold-climate air-source heat pumps. That study monitored around forty homes in Massachusetts and New York that use heat pumps as their primary or only source of heating over the last month. Results of that study are expected to be made public sometime this fall.

If you want to learn more about the Whole Home Air Source Heat Pump pilot, MassCEC published a series of blog updates on the pilot.  Reach out to us at any time at



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Operating tips on how to use your air-source heat pump

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Tips from an installer about how to be comfortable, save money, and run your ASHP efficiently

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Colonial house installs air-source heat pumps in transition to clean energy

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Residential Guide to Solar Electricity

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Solar Electricity for Landlords and Tenants

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Air Source Heat Pumps Improve Air Quality and Energy Efficiency

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Air-Source Heat Pumps replace legacy electric heating

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Ground Source Heat Pump

Ground-Source Heat Pump Provides Heating and Cooling in One Quiet System

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Solar Hot Water: The Technology, System Types, and Benefits

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solar hot water

Solar Hot Water provides savings, cool basement in summer

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Oil is out, air-source heat pumps and heat pump water heaters are in

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Comfortable ducted air-source heat pump replaces old, inefficient oil boiler and baseboards

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Automated Wood Heat: The journey of a wood pellet

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Renovations, rodents, and renewables

Location: Concord, MA
Type of home: Single Family
When first built: 1974
When last renovated: 2019

We bought our 46-year old, wooden clapboard house about five years ago and it seems like we’ve been immersed in home projects since then. The house has 2,600 square feet of living space on two floors, an unfinished basement, and a two-car garage with an unfinished space on the second floor above it. Not all of our projects have been energy-related but we’ve tried to improve efficiency as we’ve tackled deferred maintenance.

We moved in near the end of the cold and snowy winter of 2015, and immediately we learned three things: 1) the house was chilly and drafty even when the thermostat was set to 70⁰ F, 2) the roof on one side of the house was prone to ice dams, which caused leaks near the ceilings in two of the bedrooms and 3) animals were living in the attic. Our clean energy home journey so far has been intertwined with correcting these three situations.


Electric service upgrade

We upgraded the electrical service to our home from 100 amps to 200 amps at a cost of $2,500 during the first month we lived in our home. Modern electric service enables us to do things like run a hairdryer and a microwave on the same circuit at the same time, which wasn’t possible prior to the upgrade. It also enabled us to install a solar PV system, which I’ll talk about later.


Attic insulation and weatherization

In our first Spring, we got an energy audit from Mass Save®. From that assessment, we got some free LED lightbulbs, learned that the attic insulation was inadequate and confirmed that numerous squirrels had taken up residence there. It turns out that a poorly insulated attic also transmits heat from the house to the roof. In the winter, this creates ice dams on a snowy roof and contributes to leaking. In the spring, we cleaned out the attic, evicted the squirrels, and then had the attic air-sealed and re-insulated by a contractor recommended by MassSave. The attic air-sealing makes the space more airtight and blocks animals from getting in, and the insulation has made the upstairs floor of our house feel much warmer in the winter.

My Clean Energy Pledge included adding large amounts of insulation to our attic.

This room used to have a wood paneled interior and now has sheetrock walls. After removing the paneling, we fully insulated the two exterior-facing walls.

The space where I’m standing is leads to our living space so this exterior door is air sealed and insulated.














I’ll take a serving of energy efficiency with my windows, garage, and lighting, please!

We did a more comprehensive round of home improvements at the end of 2018 through early 2019. Though most of the house’s windows are double-pane with fiberglass frames, we had some original wood-frame windows left on the house that were deteriorating. We replaced them with double-pane windows, which are more insulating in winter than the windows that were there before. They have a U-Factor of .30, on a scale of .25 – 1.20, with a lower number being best. I do see that they are Energy Star certified for mid-Atlantic states but not MA, and I would definitely prioritize windows that are efficient for the MA climate in the future.

In addition, the part of the garage where the wood meets the foundation, called the sill, was rotting & needed to be replaced. In the course of that project, the garage walls were insulated with blown-in cellulose insulation. Why insulate the garage walls if we don’t live in that space? We think we might eventually finish off the space above the garage and it’ll be more efficient to heat and cool that room if it’s not exposed to extreme heat and cold underneath it. Its also great for the garage to be warmer than the outdoors in winter, since it shares one wall with our current living space.

We had almost no overhead lights in the house and craved a brighter environment. We had recessed LED lights installed in multiple rooms and learned that instead of the tall cylinders that used to be required to achieve the same look, now there are much thinner light assemblies that don’t disrupt the insulation above and around them. Whereas “can” lights used to require an insulating box around them or need air sealing, the new version is hassle-free and compatible with our insulation improvements.


Weatherization results

The winter of 2019-2020 was the first one with the house out of renovation mode and with weatherization and energy efficiency measures in place. It was also a warmer winter according to the number of “heating degree days” as compared to past winters. Our gas bill from that winter was about $300 lower than in previous years. You can see in the graph above that our natural gas use correlates closely to the number of heating degree days within each bill cycle. The gas usage from June – September is associated with cooking and hot water only.


The winter of 2019-2020 was the first one where the house was not under construction and we could get the benefit of our energy efficiency upgrades.


I think it’ll take a couple more winters to accurately quantify the savings from our energy efficiency and weatherization improvements. I can attest that the house felt cozier last year and seemed to be a more even temperature in all the rooms. Eventually we’ll replace our gas furnace with heat pumps, but that’s a topic for a future blog!


Even on a wooded lot, solar works for us

We didn’t really think our house got enough sun to be a candidate for solar panels. But using the Project Sunroof tool on the EnergySage website, we were able to see that our roof had good sun exposure. Here’s the view of our southwest-facing roof, now with the solar panels on it.


Aerial view of our home’s roof after solar panels were installed.


We learned that our investment in solar panels would pay for itself over time, meaning that the electric bill savings and SREC-II payments we’d get would equal what it cost to install the system and then we’d be cashflow positive after that. The idea of generating clean electricity and making money using our roof space appealed to us.

In late 2017, we had a 7.7 KW system installed. Given that the roof had previously been leaking during the winter, we decided to also replace the roof on the part of the house where the solar panels were being installed. That increased the cost of the project but gave us the peace of mind that the roof beneath the panels will last at least as long as the panels, and wet weather won’t damage our house. We chose to purchase our solar energy system, rather than enter a third-party ownership arrangement, because we had the financial flexibility to do that. Here’s an interesting graph that shows our electric bills the year before we had solar installed and the two years after:


Starting in early 2018 when we had a solar electric system installed, our electric bills are lower overall and nearly vanish from May – October.


Here’s how the investment in solar has worked out financially, so far. We love seeing really low (and sometimes negative, meaning we’re getting credit towards future bills!) amounts on our electric bills. We’ve only gone through one full year with the system and its associated payments and credits. Right now it looks like the cost of the system after incentives and tax credits will have been paid back by our electric bill savings and SREC-II payments after 7.5 years.


This is my tracker of our solar incentive payments and energy savings as compared the year before our solar installation.


What we’ve learned

  • Standard free energy audits won’t cover the entirety of the energy efficiency measures you need to take in your house. Feel empowered to start with those free recommendations and take it further, especially in older homes.
  • Contractors or architects won’t always have energy efficiency front-of-mind when discussing home improvement plans. Be comfortable advocating for solutions that serve a shared purpose of reducing your home operating costs, lowering emissions, and improving the way your home looks.
  • Export your utility bill history from the respective online billing portals. Even if you haven’t made energy-related improvements yet, you need a baseline to compare your improvements to. I found it hard to get more than three years of billing history, even though we were the ones paying those bills in 2015 and 2016.
  • Keep records that help you articulate the value of your energy-related home improvements. When we eventually sell our home, its monthly operating cost will likely be lower than other competing homes of the same age that are for sale. Until then, we are happy to enjoy these improvements that make us more comfortable and help reduce the carbon footprint of our home!



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Weatherization is the process of sealing up air leaks and adding insulation in your home.

Be more comfortable and save money right away by reducing the need to supply heat in the winter or cooling in the summer.

When you are ready to replace your heating or cooling system, you’ll be able to save money by installing a smaller system.

Mass Save:

Other Weatherization Resources:

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Clean Energy Solutions in Nantucket

Air-Source Heat Pumps provide quiet and comfortable heating and cooling

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Planning for Net Zero: One Step At A Time

Location: Newton, MA
Type of home: Condo in Two- Family Building
When first built: 1915
When last renovated: 2012


Seven years ago, I bought the upper condo unit (second and third floor) in a two-family home that had been updated and converted to two condos.  It was built in 1915. My unit is 1,900 square feet and has a recently replaced (but not very efficient) gas boiler, a gas hot water heater, no central air conditioning, and a new gas stove.


Added Insulation Inside Knee Wall

Energy Assessment for our Condo

One of the first things I did when I moved in was to ask for a MassSave® no-cost energy assessment.  The assessor gave me free LED lights and identified there was almost no insulation in the walls and single paned, very leaky windows in the basement.  I didn’t know my downstairs neighbor well enough to get approval for wall insulation (it would have required us to participate at the same time) so I had a MassSave® insulate the knee walls on my third floor.

What in the world is a knee wallI didn’t know myself!  When an attic space has been converted into living space under a pitched roof, you often get short “knee walls” on the side. As you can see in the photo, MassSave® added insulation foam board so air and heat would no longer gush out of the third floor and be wasted. MassSave® paid for 75% of the $2,300 cost for the knee wall insulation.

Knee Wall

At the same time, I replaced four single-paned windows in our basement that were in terrible condition. I took out a 0% 7 year MassSave® HEAT Loan to finance the window replacements.





Energy Assessment for the Building

After 3 years of getting to know my condo neighbor downstairs, I was able to convince her to have MassSave® come back again to insulate the walls. HomeWorks (one of the MassSave® Home Performance contractors) was able to blow in cellulose dense pack insulation made of recycled newspaper from the outside of the house.  MassSave® paid for 90% of the insulation cost.  For $11,000 of wall insulation work, my condo-mate and I each paid $500 only each.  What a deal!  Both of our units have been so much more comfortable in the winters since!



Weather Stripping for Door to Unheated Porch

New Air-Tight Recessed Light

Got Rid of Other Drafts

Even though MassSave® didn’t identify areas where I had a lot of air leakage, I’ve been on a mission to stop wasteful and uncomfortable drafts. The worst offenders were 12 recessed lights on my 3rd floor and edge of kitchen that go directly to the outside cold air.

Recessed lights are notorious for leaking a ton of air.This means higher heating and cooling bills and  persistent drafts. I had my electrician switch out the lights for air-tight versions that have a glass face.  There are also inexpensive retrofit kits available.

I don’t use my fireplace, so I added a removable chimney blocker I bought online and I also bought peel and stick weatherstripping for a door that leads to an unheated porch that was leaking a lot of air.



Results = Savings + Comfort

It’s hard to estimate exactly how much energy we are saving.   My best guess is there is slightly more than a 30% reduction in heating and cooling energy. The biggest difference though is clearly in comfort!  It is so much more comfortable in the winter.   And feel I good helping our climate by cutting down on wasted energy in our home.

When trying to improve the efficiency of your home, my advice is to take advantage of MassSave®.  It’s a great deal and they are much better at recommending insulation than in the past.  But that is not enough to make your home efficient!  Think through what air leakage problems you might have and/or bring in an energy professional to take your home to a higher level.



Chose 100% Renewable Electricity

Buying Renewable Electricity with MassEnergize

The City of Newton has competitively procured renewable electricity, so for a tiny premium (for me it’s been less than $1 per month more) I choose to buy 100% local renewable electricity.

If you live in a town that doesn’t have municipal aggregation for renewable electricity, there are still many options for buying 100% renewable electricity for a small premium.  Contact your local environmental group or a group like MassEnergize for suggestions for companies to buy from (you do want to watch out for scam artists). A community solar subscription is another possibility.



My Electric Vehicle

Replaced Car with An Electric Vehicle

I had one car, a twelve year old Prius, for our family.  For awhile I’ve been wanting to purchase an electric vehicle (EV).  When my oldest son needed a car for a job in Vermont, it was the perfect excuse for me to get an electric vehicle.

Green Energy Consumer’s Alliance was incredibly helpful in answering my questions and narrowing down which models would be best for me.  They also pre-negotiate bulk prices at many dealerships in Massachusetts.  Teslas were too pricey for me.  I seriously considered buying a Chevy Bolt (several of my friends love theirs) There were a number of 3 year old Bolts coming off leases.  But in the end, I sprang for a 2020 Nissan Leaf with a 230 mile range.

I am so pleased with my purchase!  The $7,500 federal tax credit and $2,500 state incentive certainly didn’t hurt, but the big win for me is avoiding the hassle of maintenance and oil changes.   With no internal combustion engine, there is very little to maintain, and I also get to avoid having to go to gas stations.  I am just using the trickle 110 volt outlet in my garage for now since I drive so little.  Because I buy 100% renewable electricity, my EV is a great choice for the climate.



Net Zero Goals

Planning to Get To Net Zero Over Time

On my list for the future:

  • Replace my gas hot water heater with a heat pump water heater. (the side benefit is that it will dehumidify our basement)
  • Install mini-split air source heat pumps for heating and cooling
  • Replace basement door which fits poorly and leaks air
  • Try again to get condo-mate to approve solar on our roof.



Putting Everything In Perspective

Do what you can.  You should absolutely not have guilt if your home is not perfect and if every action you take isn’t the best possible environmental decision. Not everyone owns a home or has the resources to get to net zero.

If you have limited funds or limited time, what is important is that you focus on the biggest personal actions you can take on climate:

  • Reduce how much beef you eat, and
  • Get on a plane only when you need to

And instead of putting in hours of research into buying most sustainable purse, fretting about using disposable or cloth diapers, the lifecycle of paper or plastic etc., spend that time and effort joining with others to take collective action related to climate.

Find a local climate group, bring your friends, and take collective action to make policy change.  A well-timed email to your city councilor, state representative, Mayor, or an editorial in your local newspaper or Nextdoor feed can make many times more impact than your personal action.

We need both the right policy framework and collective personal action to get to the state’s climate goals. What is important is that you do the best you can to contribute in the best way you can.



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Getting a century-old triple decker ready for the next 100 years

Location: Jamaica Plain, Boston, MA
Type of home: Triple-decker
When first built: 1929
When last renovated: 1988

For the last six years, I’ve lived in the first-floor condo of a triple decker in Boston’s Jamaica Plain neighborhood. The building was built in 1929 and divided up into three condos in 1988. I found this personal history from Magnuson who grew up on the third floor of my building in the 1950s and 60s, and he tells the story of the first time this building went through a major HVAC upgrade.

Roy Magnuson said, “One big issue was the heat. Not enough of it in winter, and too much of it in summer.” It turns out that the house was heated by a coal-fired boiler that was a big ordeal to start every winter and had to be loaded several times a day until the 1960s, when it was converted to oil. The hot water was heated with a very dangerous-sounding unvented appliance in the kitchen called “the stack.” So you can imagine that Roy was excited to have the heat and hot water switched over to an oil boiler. As for cooling improvements, Magnuson describes how his mother saved money from her job to buy “two small air conditioners, one for each bedroom” in the mid-1960s, making their family one of the first in the neighborhood to have air conditioning.


Oil Heat’s Not a Treat

The oil heating that our unit still has today (not the same boiler, ours was installed in 2011) is undoubtedly an improvement over the manually loaded coal boiler and “the stack” that Magnuson describes, but our radiators still clang and bang like the author remembers, and we’ve never been able to get our hot water to stay hot for an entire shower, especially in the winter. For cooling, we still use window air-conditioners. We had two (one for each bedroom) just like Magnuson until we had to stay home for parental leave in the summer and got a third one for the living room. If we’re going to be working from home more often, cooling will become more important to us.


An Air-source Heat Pump

A Solution for Both Heating and Cooling

We’re planning to switch our home over to air-source heat pumps, which provide both heating and cooling, at some point in the next year or two.

Because we have oil heat, we are eligible for generous incentives through Mass Save, although I expect it will still be a relatively expensive investment in our home. In MassCEC’s whole-home air-source heat pump pilot, the average retrofit project has cost just under $22,000 before incentives for homes averaging 1,600 square feet.

With a condo around 1,000 square feet, I’m hoping that my costs will be lower. I am definitely planning to use Mass Save’s 0% interest 7-year HEAT Loan to spread out that cost.


My electrical panel with 100 amp service.

But First, an Electrical Service Upgrade

To accommodate air-source heat pumps, our home requires an electrical service upgrade. The condo currently has 100 Amp service, and I would most likely need to upgrade it to 200 Amp service if I want to install heat pumps (and a heat pump water heater and electric car charger) in order to have enough electric current to serve all those electrical appliances. Typically, MassCEC estimates that this upgrade would cost $2,000 to $3,500. However, for some households it can cost more, especially if the electric service to your home is buried underground. My electric service is overhead, but I had an electrician come look at my home, and they said that in order to meet code, if they upgraded the service they would also need to move the electric meters from the basement to the outside of the home and they would need to add a common meter for our triple decker (we currently just have three, one for each unit). All these changes meant that the quote to upgrade my electric service was $6,800. Honestly, I’m a bit stuck on this issue. For now, I am just planning to have an electrician install a double pole 30 Amp circuit breaker to add a heat pump water heater (discussed below) and monitor what our actual amp draw is before we start thinking seriously about our air-source heat pump project. For more information on electric service upgrades, including resources to determine your home’s existing electric service (amperage) see our Electrical Service Upgrade page.


Energy Assessment for Our Condo

Before we put in a new heating system, I want to make sure that we’ve made our home reasonably energy efficient. We have had a no-cost Mass Save home energy assessment, which found that there is already blown-in cellulose insulation in our walls. Although it is a little loose and has some gaps, because there was already some insulation in the walls, Mass Save couldn’t recommend new insulation.


Energy Assessment for the Building

As I’ve thought more about the building, it would be ideal to get my upstairs neighbors onboard and request another assessment (you can have an assessment done every two years) but do one for the whole building this time so that we can think holistically about the roof and basement. I also want to ask about opportunities for air sealing and see if we can weatherize our front and back doors, which have visible gaps between the door and doorframe. Windows are not generally a cost-effective energy efficiency upgrade, but they can be nice for comfort and add value to a home. We have a broken window in our dining room (if you try to open it, it falls out of the window frame), so I would like to get the dining room windows replaced and maybe also upgrade the windows in our bedroom for comfort.


Hotter Hot Water Needed

We would like a new hot water solution sooner rather than later because we currently get hot water from a tankless coil in the boiler and it often doesn’t stay as hot as we’d like. This issue is seeming more urgent as our toddler grows out of his little tub and we want to give him baths in the larger tub. Solar hot water can be a great (and affordable) option for some homeowners. In my case, because I share a roof with my neighbors, I’m planning to get a heat pump hot water heater instead.


Heat Pump Hot Water Heater

A heat pump water heater would go into our unfinished basement. In the summer, the cooling and dehumidification that it provides will be great for the basement. We will have to see what works in the winter. I have talked to one installer who has put heat pump water heaters into similar basements and he recommended that we put it in heat pump mode in the warm months, hybrid (heat pump and electric resistance mode combined) in the shoulder seasons, and switch it to electric resistance in the coldest months of the year. We’re hoping to make this upgrade soon, while being careful about having people into our home during the pandemic.


My toddler “cooking” on our induction stovetop. I appreciate that it is safer than natural gas both in terms of burn risk and indoor air quality and health impacts.

We’re Cooking (Without Gas) Now!

We replaced our stove/oven in 2018 before the birth of our son. We had an old gas stove, but it was at the end of its life (none of the pilot lights worked anymore, so we were lighting the stove with a lighter). We decided to get an induction stove, and we have been really happy with the new stove for the last two years. We had to swap out a few cooking pans, but the stovetop heats up quickly and has good temperature control. With a glass top, it’s easy to clean. As a parent to a toddler, I appreciate that the dials are out of the way and even if my toddler did manage to turn them there would be no gas leak or open flame. In fact, the stovetop doesn’t even get hot unless there is a pan on it. This has made it a lot more stress free to have my son play at cooking on our stove. But as a parent, I especially appreciate the health benefits and improved indoor air quality of not cooking with natural gas.


Car-free Now, EV Eventually

As Roy Magnuson remembers from his childhood, “One reason why JP was a great place to live was the public transportation.” That’s still true today (although it sounds like there actually were better public transit options for Roy), and we’ve been able to get by without a car so far. However, with a toddler, we’re certainly thinking about getting a car. If we do, we’ll get an electric car. There are more and more options on the market each year, and we would probably go through Green Energy Consumers Alliance’s Drive Green program to get a good deal(and take the stress out of negotiating a car price).

For charging, we have a parking spot in our driveway where we could keep the car. At a minimum, we could charge the car through a regular outdoor outlet.

EV charger photo credit to Marco Verch via CreativeCommons

We might like to install a Level 2 charger which would let us charge the car faster, but that would require the electric service upgrade that we are currently stuck on.


Clothes Dryer

We already have an electric clothes dryer that works fine. We’ll keep using it until we start to have issues, and at that point hopefully there will be even more heat pump dryer options on the market. It would be nice to have a dryer that didn’t require venting and be able to get rid of that opening to the outside. Not to mention having a much more efficient dryer!


Renewable Electricity Plan

We buy electric offsets through Green Energy Consumers Alliance’s Green Powered Program. I like that they support renewable energy projects in New England. Our building’s flat roof is probably a good site for solar PV, but with the joint ownership and the three separate meters, I haven’t pursued it.

Resources that have recently been, are in, or are contracted with Green Energy Consumers Alliance.


Our floorplan

Triple-Decker Design Challenge

And for all of the rest of you out there who live in triple deckers, I’m keeping an eye on MassCEC’s Triple Decker Design Challenge. MassCEC asked for proposals from design/build firms, architects, and others to identify replicable triple-decker energy retrofit approaches to make these homes into high-performing, low-carbon buildings. MassCEC is offering approximately 9 prizes starting at $15,000 for the best solutions. See the ideas we received!

We’re In This Together

Pledge to reduce your home’s carbon footprint by replacing old systems and appliances with clean energy technologies over time.