FHB Logo Facebook LinkedIn Email Pinterest Twitter Instagram Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Fine Homebuilding Project Guides

Energy Retrofit

Guide Home
Chapter
  • Energy Efficiency
  • HVAC Systems and Water Heaters
  • Air-Sealing and Insulation
  • Solar Power and Electrification
  • Deep Energy Retrofits
  • Energy-Efficient Houses
How-To

Deep Energy Retrofits Are Often Misguided

It’s time for energy retrofit specialists to overcome their prejudice against solar PV systems.

By Martin Holladay
Deep energy retrofit jobs are frighteningly expensive. The energy retrofit work at this house (61 Oakwood Avenue in Sudbury, Massachusetts) cost $241,000. Image Credits: National Grid

All through the 1980s and 1990s, a small band of North American believers worked to maintain and expand our understanding of residential energy efficiency. These were the pioneers of the home performance field: blower-door experts, weatherization contractors, and “house as a system” trainers. At conferences like Affordable Comfort, they gathered to share their knowledge and lick their wounds.

These pioneers understood what was wrong with American houses: They leaked air; they were inadequately insulated; they had bad windows; and their duct systems were a disaster.

Occasionally, these energy nerds would scoff at millionaire clients who were more interested in “green bling” — a phrase that usually described photovoltaic panels — than they were in reducing air leaks in their home’s thermal envelope.

A shared belief

What I’ve just described is (in anthropological terms) a set of beliefs associated with a distinct subculture. Our tribe had a shared belief: that improving a home’s thermal envelope is preferable to installing renewable energy equipment.

Occasionally, a few facts would appear to undermine our belief system. For example, if a disinterested observer noted that a proposed envelope measure had a very long payback period, most members of our tribe would answer that the measure was a wise investment, because energy prices are likely to skyrocket in the future.

During the waning years of the last millennium, these North American beliefs crossed the Atlantic and were adopted by a group of academics in Darmstadt, Germany.

The beliefs became petrified in a set of rules called the Passivhaus standard.

Times have changed

Several factors have changed since these beliefs were first formulated. For one thing, fossil fuel prices have stayed low; for another, photovoltaic equipment has gotten dirt cheap.

The (sometimes painful) fact is that it is now hard to justify many energy-retrofit measures that energy experts still eagerly recommend. Moreover, solar bling now has a fast payback.

In short, the world has turned upside down.

photovoltaic system
In many areas of the country, a photovoltaic system has a fast payback. Image Credit: EnergySage.com

The collapse of the deep energy retrofit movement

The first deep energy retrofit occurred in 1982, when Rob Dumont and Harold Orr lopped off the roof overhangs of a ranch house in Saskatoon. Interest in deep energy retrofits has waxed and waned since then; the movement had a mini-revival three or four years ago.

Even though true believers still hope to see millions of homes undergo deep energy retrofits, at this point the movement is dead in the water. The cost of these jobs is unjustifiable.

Even back in 1982, Dumont and Orr were far from enthusiastic proponents of the deep energy retrofit approach. In their report on the Saskatoon retrofit experiment, they wrote, “Without question, there are many instances in which economics, based on a cost-benefit analysis, would not support the application of [the chainsaw retrofit] measures described here.”

Expensive and risky

The point was further driven home at a presentation given by Paul Eldrenkamp and Mike Duclos at the recent BuildingEnergy 14 conference in Boston. Eldrenkamp is a remodeling contractor, and Duclos is an energy consultant; their presentation was titled, “Three Deep Energy Retrofits, Three Years Later.”

Endrenkamp shared detailed cost information on one of the three projects he discussed: a 5,600-square-foot duplex in Belmont, Massachusetts. The cost of the project’s energy-related work was $258,000.

Eldrenkamp noted that the payback period for many deep energy retrofit measures is quite long. He pointed out, for example, that when a designer specifies 4 inches of polyiso for exterior walls, the last 2 inches of polyiso has a payback period of “maybe 160 years.”

Rigid foam delivery day
Rigid foam delivery day! This is a photo of the rigid foam used for one of the deep energy retrofit jobs described by Paul Eldrenkamp and Mike Duclos at their presentation at the BuildingEnergy 14 conference in Boston. Image Credit: Paul Eldrenkamp

He also noted that it’s very hard for a remodeling company to make any money on this type of work. “These projects are really expensive and really risky, and I don’t think they are a terrific business model,” said Eldrenkamp. “I feel no confidence that deep energy retrofits will get us very far in terms of the challenges we face. We have to come up with other tools. We have to make sure that our new buildings make sense; most of our new buildings make no sense.”

Summing up, Eldrenkamp said, “We can’t do it with deep energy retrofits.”

Then Duclos chimed in: “We need to look at low-hanging fruit like lights and appliances.”

And Eldrenkamp responded, “Right. And focus on occupant behavior. And then install PV.”

The argument in favor of PV keeps getting stronger

This isn’t the first time that I’ve pointed out that installing a PV system makes more sense than investing in a deep energy retrofit. I wrote an article on the topic in 2010 (“Energy-Efficiency Retrofits: Insulation or Solar Power?”) and another article in 2012 (“The High Cost of Deep-Energy Retrofits”).

Every time I write about the topic, I realize that the economic argument has become even more compelling that the last time I looked into it. Natural gas has gotten cheaper; so have PV modules.

Overcoming our prejudices

There’s a moral to this story. It’s aimed at the tribe I belong to: the energy nerd tribe. It’s time that we faced up to our prejudices — especially our prejudice against solar equipment.

If you’re giving advice to middle-class homeowners who hope to lower their energy bills, start with an energy audit. Once you’ve done the audit, run the numbers.

Assuming the house has an unshaded south-facing roof, it’s probable that the best energy-saving measure will prove to be the installation of some solar bling.

Two counterarguments

I anticipate that some readers of this blog will disagree with my conclusions. Here are two likely counterarguments:

Today’s net-metering contracts are likely to change, so the payback period for PV is about to lengthen. This issue is political, not scientific, and it is clearly impossible to predict which way future political winds will blow. Nevertheless, I feel that any upcoming changes to net-metering contracts won’t be significant enough to fundamentally change the direction of current trends regarding PV payback.

For more perspectives on this issue, see The Big Allure of Cheap PV, including the discussion in the comments posted at the bottom of the page.

It doesn’t matter what it costs to perform a deep energy retrofit; we need to cut down on carbon emissions to save the planet, even if our efforts are costly. Of course, any homeowners who are committed to reducing their environmental impact are free to invest in a deep energy retrofit if they want, even if the payback period is 100 years or more. But from a policy perspective, such investments make little sense.

If a government wanted to create an enlightened environmental policy aimed at reducing carbon emissions, it wouldn’t invest in deep energy retrofits. (Sadly, very few national governments are interested in reducing carbon emissions, but that’s a topic for another blog.) There are countless examples of low-hanging fruit that could be picked if we wanted to develop better incentive programs to achieve carbon reductions: we could increase our investments in low-income weatherization programs, for example, or create better programs aimed at improving vehicle fuel efficiency or phasing out coal-fired power plants.

Deep energy retrofits don’t appear anywhere near the top of such a list. From a policy perspective, every billion dollars spent on a low-yield carbon reduction measure is a billion dollars that isn’t available to invest in a more logical approach to carbon reduction.


Originally published on GreenBuildingAdvisor.com. 

Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters
Previous: Deep-Energy Retrofits versus Reductions Next: Deep-Energy Retrofit Dropout

Guide

Energy Retrofit

Chapter

Deep Energy Retrofits

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Energy Retrofit

Energy Retrofit

Trusted, comprehensive guidance from the pros for making energy-efficient updates to any home

View Project Guide

View All Project Guides »

Become a member and get unlimited site access, including the Energy Retrofit Project Guide.

Start Free Trial

Energy Efficiency
  • Understanding Energy Efficiency
  • Net-Zero & Passive Houses
HVAC Systems and Water Heaters
  • Heating and Cooling Systems
  • Ventilation and Dehumidification for Good Air Quality
  • Water Heaters
  • Heat Pump HVAC
  • Minisplits
Air-Sealing and Insulation
  • Air-Sealing
  • Insulation
Solar Power and Electrification
  • Solar Power
  • Energy Storage Options
  • All-Electric Homes
Deep Energy Retrofits
  • Deep Energy Retrofits 101
  • Featured Deep Energy Retrofits
Energy-Efficient Houses
  • Energy-Efficient Houses

Fine Homebuilding

Follow

  • twitter
  • facebook
  • instagram
  • pinterest

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences

Taunton Network

  • Green Building Advisor
  • Fine Woodworking
  • Fine Gardening
  • Threads
  • About
  • Contact
  • Advertise
  • Careers
  • Copyright
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2023 The Taunton Press, Inc. All rights reserved.

X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Shop the Store

  • Books
  • DVDs
  • Taunton Workshops

More

  • FHB Ambassadors
  • Reader Projects
  • Podcast
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • twitter
  • facebook
  • instagram
  • pinterest

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in