Reports from Owners of High-Performance Homes

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Reports from Owners of High-Performance Homes

Owners of new energy-efficient homes talk about the joys and frustrations that accompanied their projects

Posted on Apr 6 2018 by Martin Holladay
prime

At Lakesideca Advisor, we urge readers who are planning to build a new home to seek out a builder who understands energy-efficient construction methods. Is this advice easy to follow? And once the new owners move into their energy-efficient home, are they happy with the home’s performance?

Answers to these questions were provided recently at a conference presentation by Matt Sargent, a senior building energy consultant at Efficiency Vermont, and William Kallock, a vice president at Integral Analytics. Sargeant and Kallock gave their presentation on February 7, 2018, at the Better Buildings By Design conference in Burlington, Vermont.

Researchers interviewed owners of high-performance homes

Sargent reported the results of research project that included interviews with 11 owners of recently completed high-performance homes in Vermont.

From the perspective of Efficiency Vermont, a nonprofit “efficiency utility” that provides financial incentives for energy-efficiency improvements by homeowners, builders, and businesses in Vermont, the term “high-performance home” has a specific definition. To be certified under Efficiency Vermont’s “High-Performance Home” program, a new home has to meet specific prescriptive requirements. (For more information on Efficiency Vermont’s “High-Performance Home” program, see Three Superinsulated Houses in Vermont.)

Sargent told the Burlington audience, “The program assumes that these will be all-electric homes heated by a heat pumpHeating and cooling system in which specialized refrigerant fluid in a sealed system is alternately evaporated and condensed, changing its state from liquid to vapor by altering its pressure; this phase change allows heat to be transferred into or out of the house. See air-source heat pump and ground-source heat pump., so we need envelope specs that are good enough for point-source heating.” The criteria were developed for the Vermont climate.

Sargent continued, “We needed feedback for the program and the contractors. Researchers wanted to know, who are these homeowners — the owners of high-performance homes? What was the construction experience like? What’s it like living in this type of home? To get answers, we conducted kitchen-table chats with 11 homeowners. Each interview lasted between one and two hours.”

The eleven homes had been occupied for between 6 months and 3 1/2 years. All of the homes were single-family homes. The homeowners “had a moderate to high income and were college-educated. Most were interested in energy efficiency and were risk-tolerant when it comes to newer technology.”

Finding a builder is tough

The Efficiency Vermont researchers asked homeowners to describe the experience of building a high-performance home. Almost all of the homeowners responded that it was difficult to find a qualified builder.

According to Sargent, many said that “they grabbed whatever contractor they could, with mixed results. Some people said, ‘It was really scary.’ They said that they wished they had an integrated team with an energy-efficiency champion to guide them. Finding a qualified contractor was hit-or-miss.”

Sargent continued, “Several homeowners said that there were communication problems with the builder. Sometimes the homeowner had to take charge, which required a significant homeowner time investment.”

Sargent concluded, “Finding a contractor was a pain point.”

It was hard to know the incremental cost of energy improvements

The second common issue raised by the homeowners: “Knowing the cost of the project was a big challenge.”

Homeowners reported that they rarely knew the incremental cost of any suggested measure; and, since they didn't know the incremental cost, they found it hard to figure out the payback.

Sargent told the Burlington audience, “One homeowner said, ‘You spend a lot for the last few percentage of savings.’”

Subcontractor headaches

Readers of GBAGreenBuildingAdvisor.com probably won't be surprised by the next finding noted by the researchers: Homeowners reported that the subcontractors on their projects didn’t always meet expectations.

Window and door problems

Homeowners complained to researchers about window and door problems, including installation problems.

For example, ganged window units that needed to be mulled in the field weren’t installed properly. Several homeowners noted that the installers of their expensive European windows did a poor job of air sealing.

One homeowner specified a glazed exterior door from a European manufacturer; the door had a latching system that engaged deadbolts at multiple locations. When Americans tried to slam this door without first putting the latch in the unlocked position, the protruding bolts damaged the jamb. This door now has a sticky note: “Don’t close the door unless the latch is in the open position!”

No regrets

The researchers asked the homeowners, “What’s it like to live in the house?”

Sargent said, “Their reports were overwhelmingly positive. They reported that their energy bills were lower than they expected. No one regretted building a high-performance house. They all cited comfort, good indoor air quality, and lower bills. One reported, ‘This totally works.’ One woman kept saying, ‘It’s tight. It’s really tight. It’s really quiet.’”

While most responses were positive, homeowners still had complaints. According to Sargent, “Some homeowners complained that the space with the heat-pump water heaterAn appliance that uses an air-source heat pump to heat domestic hot water. Most heat-pump water heaters include an insulated tank equipped with an electric resistance element to provide backup heat whenever hot water demand exceeds the capacity of the heat pump. Since heat-pump water heaters extract heat from the air, they lower the temperature and humidity of the room in which they are installed. was cold. Some homeowners complained that the heat-pump water heater was noisy; one of these water heaters had to be moved because of the noise. And two homeowners didn’t like their induction stoves — they were worried about electromagnetic fields.”

There were several issues with the minisplit heat pumps, ranging from complaints about noise, vibration associated with wall-hung exterior units, and problems with heat distribution.

Sargent said, “At one of the homes, we arrived for the interview appointment and found there was a whole team of heat pump technicians tearing apart the heat pump for the third time.”

Some homeowners complained that the CERV unit (a type of energy-recovery ventilator with an integrated heat pump) was noisy. Sargent noted, “The CERV kicks into recirculation mode every so often to take air quality readings. It comes on at maximum fan speed, which can be noisy. One homeowner reported that he just turns the CERV off at night because it is so noisy. It’s possible to program the unit to turn down the recirculation fan speed to 50%, but most people don’t know that. To the homeowners, it’s a black box. Most people don’t know how to run it.”

Sargent continued, “Most people said they wished they had an owner’s manual for the CERV, the minisplit heat pump, and the heat-pump water heater.”

Some homeowners complained of cold concrete floors. “At one house I visited for an interview, I slipped off my shoes at the door,” Sargent recalled. “The homeowners kept the house at 63 degrees. It was a slab-on-grade house with a polished slab. I was standing in the kitchen and my feet were freezing. I think the floor temperature was in the upper 50s. The homeowners were used to it, but other homeowners complained about cold slabs. The other thing is that there is a huge thermal lag time if you go away for the weekend and come back to a cool house. It takes three days for the slab to come up to temperature.”

An audience member asked about the specified levels of sub-slab insulation. Sargent said, “We want to keep the slab within 5 degrees of the air temperature, so the program calls for R-30 under the slab for a slab on grade. We specify R-20 for basement slabs.”

A Passivhaus completed in 2012

In the second half of the presentation at the Burlington conference, Bill Kallock described his experiences living in a high-performance home that he built in 2012 in Charlotte, Vermont. The 2,348-square-foot house has a HERS Index of 29.

Kallock reported, “We were going for Passivhaus. The house has R-60 walls and R-104 attic insulation. We’ve got R-54 rigid foam under the slab, and R-43 spray foam on the foundation walls. We’ve got Fibertec triple-pane low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. windows. So our annual heating loadRate at which heat must be added to a space to maintain a desired temperature. See cooling load. is low.

“We use a Zehnder ComfoAir HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air. with a ComfoFond glycol ground loop. The buried ground loop is really good. It raises the temperature of the incoming air from 10 degrees to 35 degrees.

“For space heat, we’ve got a Mitsubishi air-source heat pumpHeat pump that relies on outside air as the heat source and heat sink; not as effective in cold climates as ground-source heat pumps.. We have an open floor plan, and one ductless minisplit on the wall heats the whole house. The heat pump uses 3,788 kWh per year. At 14 cents per kWh, we spend about $530 per year for space heat. We added 7.4 kW of PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow. after a few years.

“Since there are two adults and two kids, we use lots of hot water — 70 gallons a day — and we wash lots of clothes. We have a solar thermal hot water system with an 80-gallon tank. The backup is an electric-resistance water heater. And we have a Bosch condensing clothes dryer.”

Finding a builder — and finding enough money

Like most of the owner-builders that Sargent interviewed, Kallock found it difficult to locate a builder with the right skill set. “A big challenge was finding a builder,” he said. “We found builders, but not ones that had experience.

“Another challenge was working with the bank. The appraiser said, ‘I can only give you a loan for X amount.’ But it wasn’t enough. There were no comparables for the appraisal. So I thought to myself, ‘Let’s do some education.’ I came up with this chart [see below] to present to the person at the bank.
This chart did the trick.”

Modular construction

Kallock continued, “We took a leap of faith and chose to go with modular construction. PBS in New Hampshire was the modular company. Our onsite contractor was Yandow Lakesideca. He didn’t have any modular experience.

“Installing the exterior rigid foam was more complex than expected. We wanted a double layer of foam on the exterior. The installation was very labor-intensive. The air sealing details also proved to be very expensive and labor-intensive.

“With a house like this, the homeowner has to be the champion. I wanted a ductless minisplit heat pump. I was going around to the HVAC contractors, asking for bids. They said, ‘You can’t heat this house from one point-source unit.’ I only found one HVAC contractor that was willing to work with us.”

“Next time, I would do it differently”

Like most owner/builders, Kallock has a “lessons learned” list. “I would do a few things differently,” he said. “When we designed the house in 2012, we decided to put in a solar hot water system. I wouldn’t do it again.”

Kallock said, “Monitoring data for the Zehnder HRV showed that the HRV wasn’t operating according to specifications. It was supposed to achieve 90% heat recovery, but it was only operating at 60%. It turned out the the core was getting frozen. Zehnder replaced the core for free.

“We also had problems with the Mitsubishi heat pump. On sunny winter days, the heat pump wouldn’t turn off because the unit wasn’t registering the return air temperature properly. We had the hand-held remote. We switched it to a wall-mounted thermostat, and that solved the problem.

Kallock noted, “We don’t have any combustion appliances. I love our induction stove. It boils water quickly. It’s amazing.

“There are lots of good things about living in a high-performance house,” Kallock said. “Our house has lots of daylight and excellent air quality. It’s very quiet and comfortable. It’s easy to operate. We’re being environmentally responsible. We can go away for a week, and even if there is a power outage, the indoor temperature won’t drop much. We’re saving money, and there are lots of non-energy benefits. We are proud of the house.

“What would I change? I’d put in a heat-pump water heater with extra PV instead of a solar thermal water heater. The house is loud indoors because of the concrete floor, and the slab feels cold in the winter. I should probably install more electric-resistance heating units upstairs and in the basement to balance things out better. If I did it again, I might add a wood stove for ambiance and backup.”

A member of the audience asked Kallock, “How was the experience of modular construction?”

Kallock answered, “I would probably not do modular again. Working with a contractor right through the project, without a hand-off, would have been better.”

The industry is changing — the problem is that it's changing very slowly

Consultants who develop specifications for energy-efficient homes often live in a bubble, and may be oblivious to the challenges that owner-builders face. In the real world, it's tough to find builders and HVAC contractors with the experience and skills to create a tight home with above-average insulation and a right-sized heating system.

Martin Holladay’s previous blog: “Newspapers Trumpeted ‘Solar Homes’ in the 1940s.”


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Image Credits:

  1. William Kallock

1.
Apr 6, 2018 9:59 AM ET

Finding a builder
by Dave B

I completely agree that finding a builder is difficult , but so was finding an architect. My experience so far has been one of confusion, booth on my part and those who I try to hire. To hire "green builders and architects in my area would have driven costs up enough that I don't know if there could have ever been a payoff period, I would have had to just been satisfied with hopefully improving my "footprint". Thankfully this site exists so I can bounce ideas off knowledgeable people and learn enough that I have acted as the G.C. Had a regular architect willing to work with me to do drawings specified by me. I hired a younger contractor to do the framing that is willing to learn and work with me, at no real extra cost, because of his interest in the "green " builds and seeing this may be the way in his future builds. Both parties did have numerous questions, but in the end understood what I was after. Now with foundation starting in weeks hopefully this will all pay off with a house I'm happy with similar to the folks above.


2.
Apr 6, 2018 10:51 PM ET

PERSIST or other efficient modulars?
by Mitchell Costa

The biggest advantages of modular should come from the controlled building environment and the ability to leverage highly knowledgeable builders on multiple home builds simultaneously. Adding exterior foam after arrival of a modular on site defeats those advantages. Modular home modules are limited in width, roof pitch and overhangs unless other measures are taken that reduce modular advantages, but there are many instances where a high efficiency modular home built within the most efficient limits could meet needs and wants for housing. Would take some innovation to figure out a tight sealing system between modules and the foundation on a PERSIST or other tight and efficient modular home, but the potential for meeting many housing needs looks high. Any GBAers know of a modular company building high efficiency homes, or brave enough to start one up?


3.
Apr 6, 2018 10:59 PM ET

Mitchell, this company sells
by Michael Maines

Mitchell, this company sells fairly high performance modular homes: .

This company sells super high performance, panelized homes:


4.
Apr 7, 2018 8:48 AM ET

Ability to leverage highly knowledgeable builders...
by Charlie Sullivan

Mitchell hit on an underappreciated advantage of factory-built houses. We are able to have this forum on GBA because we are all using microprocessors designed by giant team of PhD level engineers, fabricated with incredibly tight process control. It's not that Intel's engineers are smarter than building scientists--it's that they get to specialize. And the knowledge of what works well is institutionalized and applied to building every microprocessor. There's no "microchip advisor" website where someone from Kansas writes in and asks how to find someone to grow gate oxide on his wafer and people suggest that he instead rent an oven, and experiment with different temperatures.


5.
Apr 8, 2018 8:19 AM ET

Interesting read...I have witnessed most of this first hand
by David Goodyear

I just finished building our house (flatrock passive) and have had similar experiences. Local builders weren't up to the challenge...So since I have some building experience I did the passive house builders course myself and wrote the certification exam. This is probably not an option for most home owners wishing to build performance homes. This being said, acting as the general wasnt easy. Dealing with trades and contractors that had very little knowledge of insulation and execution of the air sealing details in the plans was a major investiment in my own time. I am confident that we would have never hit 0.29 ACH on our second blower door test if the details had been left in the hands of other people.

It was hard to know the incremental costs...they are substantial and rack up quickly. This was a worry from the start but I was prepared monetarily to deal with those costs. The bank didn't care about the extra costs and my appraisal came in low because the appraiser failed and basically refused to consider that energy upgrades were valuable. So basically, the appraisal was based on uncomparable "comparables".

Our concrete floors are fine. With an interior temperature of 20 C and R40 under the slab I don;t find them to be uncomfortable...my wife has expressed that her feet get tired quickly with the hard floors so we have had to place anti fatigue mats in certain places in the kitchen.

The house is by far the most silent house I have ever lived in. It is quiet beyond belief...it takes about 70 km winds to really know there is anything on the go outside. Even rain clicking against the windows is more muffled than our previous house. I will note that it is eerily quiet on times....so much that you hear "house sounds" more than you ever did before. I am guessing that concrete floors and less ambient noise amplify certain sounds. It is the most comfortable house I have ever lived in. You can sit by the window when its -10 C and there are no drafts from the cold panes and overall you feel the same temperature everywhere. Less thermal bridging and higher mean radiant temperature due to the constant temperatures of surrounding objects plays a huge role in human comfort.

Installing an ERV was a great idea. As expected, the ERV maintains higher indoor humidity in the winter. It is much more comfortable than our previous house. There have been no compaints about dry skin, night time coughing, dry noses, etc since we moved in.

The house is bright, even on cloudy days. The large windows are great and the wide window sills look amazing.

Electric baseboards in the bedrooms and a minisplit would have been a much more cost effective option then my hydronic electric/wood fired system. This being said, I love my hydronic radiators and my wood stove so I wouldn't trade it. However, from a builder point of view, electric baseboards and a minisplit would be a more profitable option and simpler for most home owners.

i have lots more to comment on but have run out of time for now......


6.
Apr 8, 2018 8:57 AM ET

I'm very confused by the
by Calum Wilde

I'm very confused by the almost 3800kWh to heat a CZ6 passive house with a living area of ~2400ft^2. That's about what we used in our CZ6 2400ft^2 house that only has R60 in the attic, "R20" walls with batt insulation, and no insulation under the slab.

In fact I've been increasingly surprised at the varying energy usage of several of the homes that have been discussed here on GBA, both in the comments of the Q&A section, and in the articles. From what I've seen I cant attribute the difference to just family size or house alone. I'm really curious if anyone has preformed a study to show how differences in usage patterns alone affect energy consumption.


7.
Apr 8, 2018 10:50 AM ET

Edited Apr 8, 2018 11:16 AM ET.

Calum...here is a link
by David Goodyear

Calum, this was posted on GBA some time ago:

http://lakesideca.info/blogs/dept/guest-blogs/measuring-pas...

Point # 2 observed by Katrin Klingenberg :"Interestingly, occupants are better than their reputation; they were not major contributors to the performance gaps.

ALthough this may be the case for this limited study, it probably doesn't apply to all homesowners.

Point #5. " Quality assurance and verification are critical to success. The experience of the team members (CPHC, builder, and verifier) and the accuracy and trustworthiness of the tools they have available to them to back-check their assumptions against reality are indispensable to achieving passive levels of performance."

I found this article to be somewhat insightful and provides a view of two models and final energy consumption patterns.

It does go to show that modeling is a great tool and indespensible to our understanding....but these tools do not construct reality....physics does that for us! After which its left to us to figure out what went wrong!


8.
Apr 8, 2018 12:12 PM ET

Calum and David
by Malcolm Taylor

Ms. Kingenberg is right, about the self-selecting group that lives in high-performance houses, but I suspect occupant behaviour is a much larger variable among typical homeowners who have little interest in the subject, or renters who don't pay utilities.

I built a fairly tight and well-insulated house two years ago where the owners leave several quite large windows open all year round, offsetting the energy loss why burning huge amounts of firewood.

Re-reading Martin's blog I wonder if even among occupants of high-performance houses we may being a bit optimistic. One couple is described as keeping their home at 63 degrees. That's got to skew results!


9.
Apr 11, 2018 2:05 PM ET

Dave B
by John Burk

I could have written your comment myself, so many parallels. I designed mine and had an architectural draftsman do up plans and mods. Expect to finish it this year and move in. Enjoy your build and I think you will be happy with the results, I am so far. I did 2x6, ply and 4" reclaimed roofing foam with 2" closed cell on interior, 6" on the roof. Even without heat on in winter it is remarkably stable temperature wise with just solar heat.


10.
Apr 11, 2018 2:43 PM ET

Edited Apr 11, 2018 9:48 PM ET.

Details on solar hot water system why "I wouldn't do it again."
by Duane Scaggs

It would be helpful to understand why "I wouldn't do it again." what issues were experienced with the solar hot water system?


11.
Apr 11, 2018 11:17 PM ET

Return on investment chart
by Kevin Brauer

I need this chart explained, please. Especially a tool purported to help address the “valuation challenge “ posed by appraisers unqualified to value green features.


12.
Apr 12, 2018 8:25 AM ET

Kevin: return chart
by Charlie Sullivan

Kevin, that return on investment chart has built in some assumption about the difference in fuel cost between the energy star and passive house designs. I don't see that assumption documented, so I don't think there's a way for the rest of us to use it.


13.
Apr 16, 2018 7:46 AM ET

Response to Duane Scaggs (Comment #10)
by Martin Holladay

Duane,
There are three main reasons why solar hot water systems are rarely installed these days. The first reason is that they aren't cost-effective -- meaning that the energy savings attributable to a solar hot water system are too low to justify the high installation cost.

The second reason (related to the first) is that photovoltaic systems are now so cheap that an investment in PV makes more sense than an investment in solar thermal for anyone with a special interest in solar power. For more information on this issue, see Solar Thermal Is Really, Really Dead.

The third reason is that solar hot water systems are mechanically complicated (especially compared to PV systems) and have high maintenance costs.


14.
Apr 16, 2018 7:50 AM ET

Response to Kevin Brauer (Comment #11)
by Martin Holladay

Kevin,
Charlie Sullivan is right: If you want to create a chart like the one shared by Bill Kallock, you need to know the annual energy savings associated with the incremental investment in energy features. This requires the use of energy modeling software, and is specific to each project.

For a thorough discussion of these issues, see Payback Calculations for Energy-Efficiency Improvements.


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