Concentration of CO2 in the Atmosphere

Energy Efficieny Remodel in Maine

An Efficiency Remodel in Maine Shows the Way

Martha and Jesper’s finished deep energy retrofit from the back. Notice the Mitsubishi mini-split at the far right. (Images: the Whitchurches)

Barb and Greg Whitchurch

Is it hard to keep your home comfortably cool when it’s very hot outside? Cozy warm when it’s very cold outside? Is it expensive to run your house in these conditions? Do you have extra machines (fans, air conditioners, space heaters) working to relieve your temperature discomforts?

Or, are you concerned about your home’s contributions to the climate crisis and pollution-caused health problems because of the fuels you use or the amounts? What about your home’s vulnerabilities to the climate crisis extreme weather? Its equity value?

Almost all recent and older homes would benefit greatly from air tightening, window upgrades, more insulation, and better mechanical systems (heating, cooling, ventilating). Beyond the obvious and immediate comfort and health improvements, these changes also save a lot of money while reducing the inflammatory effects on our weather and climate from wasteful leaks and losses.

Beyond weatherization is the Deep Energy Retrofit (DER), where the foundation, outside walls, windows and roof are all addressed. Centuries-old farmhouses and homes built earlier this century are undergoing DERs.

Fortunately, about 20 years ago the engineering standard called Passive House (PH) accomplished the Holy Grail of building design and construction: namely, sweet-spot targeting of comfort, health, energy use, simplicity, and price-point cost-effectiveness across all types of buildings. This development has shone a spotlight on the weaknesses of standard construction practices (

So, PH DERs are all the rage now, with the major benefits going toward the occupants, utility bills and the environment. Whether one ends up with the formal PH Certification plaque or whether they’ve made it most of the way but had to come up a little short for some reason or other, following the PH path results in a pleasing and finally permanent solution. A DER doesn’t just bring your home up to date, it’s more like finishing it, finally! And, just like with electric cars, maintenance is minimal to none, especially when compared to what one started with.

Martha McLean, a Spanish teacher now turned private attorney, and her husband, Jesper Kruse, built their own home in 2000 in Greenwood, Maine. Jesper, originally of Denmark, had been working as a carpenter for about three years, and while he worked with a construction company and she as a teacher, they built their home in their spare time: Six-inch cellulose-filled walls, insulation board under concrete slab, 16-inchcellulose in the attic, nicely designed – quite an accomplishment. But over the years they came to realize that they came up short, comfort- and efficiency-wise; and when their Brosco wood windows began to fail after a dozen years, they slowly and incrementally came to realize that replacing those windows really should be the catalyst for addressing shortcomings in the entire envelope. Hence, a DER was born!

Martha and Jesper’s finished deep energy retrofit

Now, the details of how they did their DER are beyond the scope of this article. Our intention here is to pique your interest enough that you would consider such an effort to improve your own life by vastly improving your home. ALL of the details of their efforts as well as all the references you’d need to seriously consider such an effort are right here in the links.

Very briefly, they dug down along the foundation and added 10 inches of EPS foam against the concrete (this broke the thermal bridge from the slab which has only two inches of XPS, but is unaddressable); they sealed an air barrier/moisture control membrane against the concrete and brought it up the outside walls to the roof; they added another 10 inches of cellulose between two-foot-on-center TJIs on the outside walls which already had six inches; they brought the wall membrane up over the roof and extended the eave to cover the widened walls; they placed a variable vapor permeable membrane over the 16 inches of cellulose already in the attic. An in-depth review of their process is here: and .

We also want to make it clear that taking a less serious path than PH toward improvements doesn’t serve your interests now or in the future, because somewhere down the road you or someone else will be facing the unmet needs left over from yet another shortfall. Don’t make that mistake!

Jesper suggests reaching out to organizations like or if you’re looking for resources. There are PH organizations in every Northeastern state, and they are there to help YOU with your dreams and needs. There are many architects, designers and builders in every state fully certified to build to the PH standard — although there are also lots of old-timey, business-as-usual pros stuck in the past who’ll try to talk you out of anything beyond what they already know. In fact, most homes under construction right now will be weatherization candidates as soon as the new owners move in.

Some states have energy efficiency utilities (paid for with tax dollars and utility bills) like Efficiency Vermont to provide free consulting services and monetary rebates for such projects. Jesper, like we and many others, also consulted with 475 Building Supply for advice and materials.

If you get in touch with a PH-certified professional, they’ll inform you of the financing, rebates and other incentives aimed at businesses which build responsibly. There are specialized low-interest “green loans” for such projects.

Most of the effort and money for Martha and Jesper’s DER went into aspects that can’t be seen in the finished product except for smiles and sighs of relief from the family. Very little was done to the inside of the home. They replaced wasteful and costly mechanicals with a Whirlpool condensing dryer, heat pump water heater, a Mitsubishi cold climate heat pump mini-split for heating and cooling, a direct vent for their Morsø woodstove, and Lunos HRV ventilators. Upgrades to the cooking and fridge, new floors, etc. will be done with their considerable energy savings.

Again, they didn’t get all the way to PH but by taking the PH road they did maximize their opportunities and got the most bang for their bucks. It’s a new home in the most important ways, yet so familiar. And they’re DONE!

The Whitchurches use induction cooking in their Net Zero+ Middlesex, Vermont Passive House, .

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