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A Northampton couple has turned their Victorian house into one of the most energy-efficient homes in the Valley

  • Adding four inches of rigid insulation to the exterior increased the depth of the window wells considerably. —GAZETTE STAFF / KEVIN GUTTING

  • Peter Stevens holds three of the various lengths of screws that were needed to attach the siding of their home through several inches of insulation. —GAZETTE STAFF / KEVIN GUTTING

  • Each residence in Peter and Rachel Stevens's two-family home has its own water heater. —GAZETTE STAFF / KEVIN GUTTING

  • Peter Stevens examines the filters on an air exchange unit in the basement of his Northampton home. —GAZETTE STAFF / KEVIN GUTTING

  • Peter and Rachel Stevens play with their daughter, Lillian, almost 2, in the living room of their Northampton home which underwent a National Grid Deep Energy Retrofit. GAZETTE STAFF / KEVIN GUTTING

  • Rachel Stevens and her daughter, Lillian, almost two, stand in the kitchen of their Northampton home. —GAZETTE STAFF / KEVIN GUTTING

  • A pair of heat pumps, one for each section of the two-family house, stand near an array of vents that help keep the air inside fresh. GAZETTE STAFF / KEVIN GUTTING

  • Hot water pipes are insulated in the basement of Peter and Rachel Stevens' Northampton home which underwent a Deep Energy Retrofit. —GAZETTE STAFF / KEVIN GUTTING

  • The couple furnished the kitchen with repurposed cabinets, a granite countertop and appliances. GAZETTE STAFF / KEVIN GUTTING

  • Rachel and Peter Stevens chat in one of the sitting areas that opens into the kitchen of their Northampton home. —GAZETTE STAFF / KEVIN GUTTING

  • Back-to-back layers of this two-inch rigid foam onto the exterior of Stevens’s home adds another four inches of insulation. Below the various lengths of screws that were needed to attach the siding of their home through the thick insulation. GAZETTE STAFF / KEVIN GUTTING

  • Two sitting areas open onto the kitchen on the second floor in Rachel and Peter Stevens’s home. GAZETTE STAFF / KEVIN GUTTING

  • Rachel and Peter Stevens chat in one of the sitting areas that opens into the kitchen of their Northampton home. —GAZETTE STAFF / KEVIN GUTTING

  • Peter Stevens checks the energy useage in his home with his phone. GAZETTE STAFF / KEVIN GUTTING

  • Peter Stevens cleans the filters of one of the head units of the "mini-split" heat pump system in his Northampton home. —GAZETTE STAFF / KEVIN GUTTING



For the Gazette
Thursday, February 02, 2017

When you walk into Rachel and Peter Stevens’s handsomely renovated clapboard house in Northampton, built before the turn of the last century, you notice the Victorian-style woodwork, large windows, and original maple and pine floors. You’re less likely to notice the many features that make the house one of the most energy-efficient structures in western Massachusetts.

Rachel and Peter are both architects who met in 2001 while working in Boston. They married in 2011 and, with an eye toward raising a family and having their own architectural practice, decided to move to Northampton. Rachel grew up in Northampton and has family here; Peter, who grew up in Los Angeles, also has family nearby. “We wanted to live in a small town,” said Rachel. “Cambridge is so intense. Even the playgrounds are competitive.”

Rachel and Peter bought their house that summer. “It had been vacant for several years and was in terrible shape. It was a bit of a flop house,” said Peter, explaining that it had been a boarding house for undocumented workers. “There were lots of small rooms with locks on the doors. Some of the windows had been painted open.”

Although the tenants had moved out, squirrels had moved in and taken over the third floor. “Their nest was the size of a VW bug,” said Rachel. “We chased them out and blocked the openings with wire, but they just ate their way back in. It was a scary place.”

The couple spent several months doing exploratory demolition and imagining what their renovated space might look like. Given that the house’s exterior siding was worn out and all the interior systems needed replacement, the couple decided to apply for National Grid’s Deep Energy Retrofit pilot program. This program gives grants to homeowners to make energy-efficient renovations and encourages experimentation with the latest energy-saving technology and construction methods.

Ambitious undertaking

They scrambled to get the application completed on time. They said that when they received the award they were excited but daunted by the program’s stringent standards and time limits for completion. “It was a lot to take on all at once,” said Rachel. “We were working on a tight budget.”

Rachel and Peter redesigned the first floor as a two-bedroom rental apartment and the second and third floors as a separate apartment for themselves. The open-plan second floor includes two sitting areas that open onto the kitchen, a bathroom and guest bedroom that doubles as an office. The third floor has two bedrooms and two bathrooms.

As Peter explained, a Deep Energy Retrofit has three components: air sealing, insulation and efficient equipment. Air sealing means making the structure airtight, so that heat isn’t lost through cracks in the building’s envelope. Air tightness is determined by measuring airflow in and out of the building with a blower door, a powerful, calibrated fan set in an airtight, adjustable frame that fills the doorway. The building team used a housewrap material taped in a continuous layer all around the walls and roof.

At first, the couple’s efforts did not meet the program’s target. “We were in panic mode because we still hadn’t hit it,” said Rachel. Using a borrowed smoke machine, they filled the house with visible theatrical smoke and then observed where the smoke was escaping from the building. They discovered leaks in the roof and at ground level and used caulk and foam to seal the problem areas. They eventually exceeded the requirements, earning a $3,000 bonus that they distributed to their workers as a reward for their painstaking efforts.

The building team added four inches of insulation under the exterior siding. They also pumped more insulation into the frame of the house and insulated the basement.

Individual systems

Having properly sealed and insulated the house, the couple installed energy-efficient equipment including heating and cooling systems and electrical appliances. “Each unit has completely separate systems so that energy needs can be targeted,” explained Peter. “For example, we travel in the summer and don’t want to turn off the air conditioning for the whole house.”

“One tenet of new energy design,” he said, “is to put more money into the physical envelope so that you can spend less money on equipment to heat and cool it.” A key element of efficiency is using equipment that is appropriately sized for the space and needs of the occupants.

The couple’s house is heated and cooled with electric heat pumps. These units are called “mini-splits” because they consist of an exterior condenser component and an interior head unit. The condenser extracts warmth from the air and concentrates it in refrigerant-filled coils that become hot. The head unit, an unobtrusive box mounted high on the wall, draws air from the room and over the coils, warming the air and sending it back into the room.

In warm weather, the heat pump generates chilled fluid that cools the interior air as it circulates. The first-floor apartment has one head unit; the upstairs apartment has four.

In the basement are two hot water heaters, one for each apartment, that have heat pumps built into them. The water heaters can be adjusted depending on the amount of hot water required at any given time. When guests come over the holidays, for example, the heater can be programmed to “boost mode” to provide additional hot water.

An important part of the energy-efficiency program is the monitoring of the electricity usage. Nine sensors measure separate electrical circuits and report wirelessly to an online database. With one swipe of their phones, Rachel and Peter can determine how much wattage each appliance is using. 

“We care a lot about saving energy,” said Rachel, noting that they have an electric car. “It used to make me crazy at work seeing computer monitors left on over the weekend. We turn off all systems that aren’t being used, including our computer servers. “People say: There’s no such thing as a ‘zero-energy’ house. There are only ‘zero-energy’ occupants.”

Keeping air fresh

To ensure the optimum amount of fresh air in the house, energy recovery ventilators bring fresh air in while pushing interior air out. As the air exchange takes place, warmth from the outgoing heat passes through a membrane and warms the incoming air. This way, it’s possible to have fresh air without losing heat through open windows and doors.

The couple designed the space for maximum cross-ventilation. “In the swing seasons we open windows for heating and cooling,” said Peter. “We use our house like a machine even when all the machines are turned off.” In warmer months, they use ceiling fans much of the time, reducing the need for air conditioning, which can be adjusted in different rooms.

The house also has 10 sensors embedded in the walls that measure temperature, relative humidity and moisture content. “This helps us see how the various layers of the house function, compared to the idealized world of theory and drawings,” he said. “It will also alert us if there are any conditions that suggest we should cut into the walls to investigate further.”

From reuse to cutting edge

The couple took energy savings a step further, furnishing the apartment’s kitchen with repurposed cabinets, a granite countertop and appliances from a friend who was installing a new kitchen. “These materials would have ended up in the landfill,” said Rachel.

The couple has experimented with cutting-edge systems and construction materials. “We are trying these out ourselves before we risk using them for a client,” said Rachel. One such material is a composite siding that includes fly ash, a waste material from coal plants. The manufacturer had intended it for exterior trim, but was enthusiastic about having the couple use it for the entire exterior and gave them a discount.

Rachel and Peter moved into the house in 2013 and their daughter, Lillian, was born two years later.

A family with two young children lives in the first-floor apartment.

“We are proud to be living the way we design for our favorite clients: in a low-energy home that invites wide-open windows at the first sign of spring,” said Rachel. “This was a big undertaking that would not have made sense in a livable home, but worked very well to bring this house back to life, from abandonment to nurturing two young families.”

Mickey Rathbun can be reached at foxglover8@gmail.com.