By William Boston

When it comes to energy efficiency, the people who design buildings and promote conservation have all sorts of insights and advice. But how do they apply that advice to their own homes?

We asked architects, policy analysts and sustainability experts to show us how they walk the talk in their own lives. And they didn't disappoint, detailing the energy-saving strategies they've adopted at home -- everything from solar retrofits to low-carbon building materials to passive design approaches such as extra insulation, shading and ventilation that aim to minimize upfront energy consumption.

Here is a closer look at some of their responses:

A home that makes more than it takes

Barry Alan Yoakum, partner and CEO of architecture-and-design firm Archimania

My wife and I decided in 2017 to invest in a world of energy efficiency when designing our new home near downtown Memphis. We began by employing as many passive design strategies as possible before resorting to more-expensive building systems and interventions. This approach helped pave the way for a faster return on investment.

The home is 2,798 square feet with four bedrooms and shared spaces such as the kitchen and living areas arranged around a courtyard. Sited on the Mississippi River with its high water table, it employs a geothermal system for heating and cooling. The home has a robust energy-efficient envelope, meaning there is little air exchange between the inside and outside, thanks to insulated panels and other barriers such as coated aluminum panels on the exterior that reflect the bright summer sun. Adjustable sun shades provide additional protection. Add five dozen solar panels and a large battery backup and you have more than a reasonable return on investment for many years to come, driven in part by selling back excess energy to the utility company.

The home, which we sold a few weeks ago for $1.35 million, produced 13% more energy than consumed in its first year of operation and 9% the following year. It was recognized as the first zero-energy and zero-carbon single-family home (or building) in the world, which means it consumes less energy than it produces and has little net CO(2) emissions.

Hens and a solar cooker

Richard Heinberg, senior fellow at the Post Carbon Institute

When my wife and I bought our house in Santa Rosa, Calif., 25 years ago, our first strategy was insulation. Next came solar panels and battery backup. Our solar hot-water heater uses almost no energy during sunnier months and is super-efficient the rest of the year. Skylights give us free daytime lighting.

Food is our most important daily energy source. We keep four hens for eggs -- which aren't cheap because we don't skimp on animal care -- and the chickens are endless sources of amusement and companionship. We have gardens for veggies and beauty, including fruit and nut trees, which provide lots of nutrition for little effort.

Our most recent additions are a heat pump for heating and cooling and an electric car; both are big money and energy savers.

Our most surprising success was a solar cooker -- a simple device consisting of a glass-lidded box and reflective surfaces that cooks our summertime dinners outside with no fuel or electricity.

We use a quarter of the energy of a typical California household.

A step-by-step approach

John Grable, architect

Over the past decade, our 67-year-old home in San Antonio has become a living experiment in energy efficiency -- proof that transformation doesn't happen overnight, but step by step, layer by layer.

The most significant shift came with the installation of solar panels. The investment paid for itself in eight years, demonstrating how sustainability is as practical as it is essential. We added deep overhangs to shade our large glass walls, improved insulation and installed steel windows that open and close to provide natural cross ventilation of breezes and fresh air. The windows are made with low-E glass, designed to be resistant to both extreme hot and cold temperatures, mounted in steel frames, which are strong enough to hold large glass panes and are more durable than wood or plastic. The addition of ceiling fans, solar shades that block direct sunlight and LED lighting further reduce our footprint.

The simplest choices make a significant impact: a gas fireplace, efficient yet effortless, replaces mechanical heating on colder days. A tankless water heater, low-flow fixtures and an insulated garage refine efficiency at every turn. We planted native trees to shade and cool the lot, and upgraded to a heating, ventilation and air-conditioning system that uses durable rigid ducts to prevent obstruction of air flow for better air quality.

The next step is a rainscreen system. This construction leaves a small gap between the home's exterior walls and the outside cladding to allow for drainage and ventilation. This prevents moisture buildup and penetration, protecting the building from rot and improving its ability to maintain comfortable temperatures with more-efficient energy use.

Airtight seals

Michelle Krochmal, owner of Filament Architecture Studio

When I renovated my home in Brooklyn a few years back, it was an opportunity to create a very energy-efficient space using so-called Passive House principles.

First, I opened up the walls and ceilings to add insulation to the entire townhouse with more than the typical amount required. This so-called super insulation pays for itself after a few years through less expensive utility bills. I also air-sealed the home to get rid of leaks, added triple-pane windows and created energy-efficient air circulation with an energy-recovery-ventilator system consisting of a fan with ductwork that pushes stale air out and fresh filtered air in while preserving the temperature inside. I also added Energy Star appliances and often air-dry my family's clothes.

I installed window boxes at the front of the home, to create a little bit of shade in the summer and a tiny bit of extra insulation. The AC and heat system is a mini-split heat pump. Finally, I have a solar array on top of our roof deck that also doubles as a shade structure. This solar power provides more electricity than we use during most of the year.

To capture natural light throughout the home, which is more energy efficient and a more pleasant space to live and work in, I strategically located skylights above the bathrooms and the stairs, and located our windows and doors to maximize light and views.

My family was most surprised by how effective extra insulation and tight seals on the windows and doors are. They can sit right up against the window and not feel a draft. They love it!

Straw wall panels

Chris Magwood, manager, carbon-free buildings, at Rocky Mountain Institute

After 20 years of helping clients achieve their energy efficiency and climate-impact goals as home designers and builders, my partner and I decided to put everything we had learned into the creation of a new home for ourselves in Peterborough, Ontario.

We started by finding an urban infill lot -- an undeveloped property within an urban area -- for the house. This type of site helps prevent urban sprawl and makes use of existing infrastructure like sewer, water and electricity. We also knew that living in a area where transit, walking and biking are feasible is an effective way to reduce our long-term emissions.

Next came better-than-code levels of insulation, triple-pane windows and airtight construction powered by efficient, all-electric systems. With 5 kilowatts of photovoltaic panels on the roof and solar hot-water collectors shading our south windows, the house is very close to net zero in its energy consumption.

Equally important, we minimized the upfront emissions that arise from the production of building materials (the "embodied carbon" of a building) by using low-carbon and carbon-storing materials throughout the house, including waste-wood foundation blocks and cellulose insulation. Our upfront carbon footprint was 85% less than a typical home.

We used prefabricated straw wall panels, which are load-bearing wall structures that use a combination of light wood framing and straw-bale insulation with a lime-based stucco coating. Straw bales are a sturdy renewable material with high-insulation value. They also are naturally fire-retardant and more affordable than many conventional materials.

Using the sun for heat -- in Maine

Timothy Lock, management partner at architecture firm OPAL

When my wife, Holly McBride -- a textile designer -- and I designed and built our home in Hope, Maine, in 2015, our goal was to maximize efficiency in energy and material use, creating open, modern spaces heated primarily by the northern Maine sun.

The goal was challenging because Maine's far northern latitude limits the length of daylight in the winter, but it was achievable with passive house design, which requires reducing energy demand by over 80% compared with standard construction.

Our strategies included a compact but open layout, super-insulated walls (13 inches thick!), triple-glazed windows for maximum solar gain and a high-efficiency ventilation system with heat and energy recovery. With our energy needs so low, adding a small solar array was an easy and cost-effective choice.

Nine years later, our investment has paid off. We have never spent more than $600 a winter on heating, largely met by a small, efficient, salvaged and refurbished wood stove. Our solar panels now also charge our EV, and the home's passive resilience has been invaluable during power outages and the pandemic. Not having to service a heating-and-cooling system has been a game-changer.

All in on electric

Graham Irwin, principal of Essential Habitat Architecture

One important thing I've done in my home in Fairfax, Calif., is to move away from natural gas toward all-electric operation any time I'm replacing something or installing new. Almost everything is better, though I've yet to find good electric substitutions for grilling, fireplaces or outdoor fire pits.

I've found induction cooking to be outstanding -- as responsive and more widely adjustable than gas, without the emissions. Heat-pump condensing dryers have come into their own. Not needing to worry about installing and cleaning a dryer vent is a huge benefit, and our clothes enjoy not being roasted, which is literally what a gas dryer does.

Off the grid

Joseph Trumpey, professor of art, environment and natural resources at the University of Michigan's Stamps School of Art & Design, School of Literature Science and the Arts, and School for Environment and Sustainability.

I designed and built a 2,200 square-foot, two-story straw-bale home in southeastern Michigan in 2007.

We focused on using local, low-energy, natural materials that could create a highly efficient yet comfortable home given the cold, snowy and wet climate. Straw is a fantastic, carbon-dense, agricultural byproduct that can create thick, efficient, insulative walls while minimizing the amount of framing lumber used in a project.

We went 100% off-grid with a 4-kilowatt photovoltaic array that follows the movement of the sun to assure optimal alignment with the sun's rays. We store the energy in a bank of 60 golf-cart batteries. We heat and cook with wood over the long winter. Michigan is a forested state, and dead and downed trees are abundant.

We haven't burned a gram of fossil fuel to heat the house, our water, or to cook our food for 16 winters.

William Boston is a writer in Berlin. He can be reached at reports@wsj.com.

(END) Dow Jones Newswires

April 20, 2025 10:00 ET (14:00 GMT)

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