net zero

How cities can fight climate change

Posted on August 10, 2022August 10, 2022 by abrahamwien18

Urban activities — think construction, transportation, heating, cooling and more — are major sources of greenhouse-gas emissions. Today, a growing number of cities are striving to slash their emission to net zero — here’s what they need to do.

By: Deepa Padmanaban
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Global temperatures are on the rise — up by 1.1 degrees Celsius since the preindustrial era and expected to continue inching higher — with dire consequences for people and wildlife such as intense floods, cyclones and heat waves. To curb disaster, experts urge restricting temperature rise to 1.5 degrees, which would mean cutting greenhouse gas emissions, by 2050, to net zero — when the amount of greenhouse gases emitted into the atmosphere equals the amount that’s removed.

More than 800 cities around the world, from Mumbai to Denver, have pledged to halve their carbon emissions by 2030 and to reach net zero by 2050. These are crucial contributions, because cities are responsible for 71 percent to 76 percent of global carbon dioxide emissions due to buildings, transportation, heating, cooling and more. And the proportion of people living in cities is projected to increase, such that an estimated 68 percent of the world’s population will be city dwellers by 2050.

“Urban areas play a vital role in climate change mitigation due to the long lifespans of buildings and transportation infrastructures,” write the authors of a 2021 article on net-zero cities in the Annual Review of Environment and Resources. Are cities built densely, or do they sprawl? Do citizens drive everywhere in private cars, or do they use efficient, green public transportation? How do they heat their homes or cook their food? Such factors profoundly affect a city’s carbon emissions, says review coauthor Anu Ramaswami, a professor of civil and environmental engineering and India studies at Princeton University.

Ramaswami has decades of experience in the area of urban infrastructure — buildings, transport, energy, water, waste management and green infrastructure — and has helped cities in the United States, China and India plan for urban sustainability. For cities to get to net zero, she tells Knowable, the changes must touch myriad aspects of city life. This conversation has been edited for length and clarity.

Why are the efforts of cities important? What part do they play in emissions reductions?

Cities are where the majority of the population lives. Also, 90 percent of global GDP (gross domestic product) is generated in urban areas. All the essential infrastructure needed for a human settlement — energy, transport, water, shelter, food, construction materials, green and public spaces, waste management — come together in urban areas.

So there’s an opportunity to transform these systems.

You can think about getting to net zero from a supply-side perspective — using renewable, or green, energy for power supply and transport — which is what I think dominates the conversation. But to get to net zero, you need to also shape the demand, or consumption, side: reduce the demand for energy. But we haven’t done enough research to understand what policies and urban designs help reduce demand in cities. Most national plans focus largely on the supply side.

You also need to devise ways to create carbon sinks: that is, remove carbon from the atmosphere to help offset the greenhouse gas emissions from burning fossil fuels.

These three — renewable energy supply, demand reduction through efficient urban design and lifestyle changes, and carbon sinks — are the broad strategies to get to net zero.

How can a city tackle demand?

Reducing demand for energy can be through efficiency — using less energy for the same services. This can be done through better land-use planning, and through behavior and lifestyle changes.

Transportation is a great example. So much energy is spent in moving people, and most of that personal mobility happens in cities. But better urban planning can reduce vehicle travel substantially. Mitigating sprawl is one of the biggest ways to reduce demand for travel and thus reduce travel emissions. In India, for example, Ahmedabad has planned better to reduce urban sprawl, compared to Bangalore, where sprawl is huge.

Well-designed, dynamic ride sharing, like the Uber and Lyft pools in the US, can reduce total vehicle miles by 20 or 30 percent, but you need the right policies to prevent empty vehicles from driving around and waiting to pick up people, which can actually increase travel. These are big reductions on the demand side. And then you add public transit and walkable neighborhoods.

Electrification of transportation — the supply side — is important. But if you only think about vehicle electrification, you’re missing the opportunity of efficiency.

Your review talks about the need to move to electric heating and cooking. Why is that important?

There’s a lot of emphasis on increasing efficiency of devices and systems to reduce these big sources of energy use, and thus emissions — heating, transport and cooking. But to get to net zero, you also have to change the way you provide heating, transport and cooking. And in most cities, heating and cooking involve the direct use of fossil fuels.

For example, house heating is a big thing in cold climates. Right now, we use natural gas or fuel oil for heating in the US, which is a problem because they are fossil fuels that release greenhouse gases when they are burned. With many electric utilities pledging to reduce the emissions form power generation to near-zero, cities could electrify heating so that the heating system is free of greenhouse gas emissions.

Cooking is another one. Some cities in the US, like New York City and others in California, have adopted policies that restrict natural gas infrastructure for cooking in new public buildings and neighborhood developments, thereby promoting electric cooking. Electrifying cooking enables it to be carbon-emissions-free if the source of the electricity is net zero-emitting.

Many strategies require behavior change from citizens and public and private sectors — such as moving from gasoline-powered vehicles to lower-emission vehicles and public transport. How can cities encourage such behaviors?

Cities can offer free parking for electric vehicles. For venues that are very popular, they’ll offer electric vehicle charging, and parking right up front. But more than private vehicles, cities have leverage on public vehicles and taxi fleets. Many cities are focusing on changing their buses to electric. In Australia, Canberra is on track to convert their entire public transit fleet to electric buses. That makes people aware, because the lack of noise and lack of pollution is very noticeable, and beneficial.

The Indian government is also offering subsidies for electric scooters. And some cities across the world are allowing green taxis to go to the head of the line. Another incentive is subsidies: The US was offering tax credits for buying electric cars, for example, and some companies subsidize car-pooling, walking or transit. At Princeton, if I don’t drive to campus, I get some money back.

The main thing is to reduce private motorized mobility, get buses to be electric and nudge people into active mobility — walking, biking — or public transit.

How well are cities tackling the move to net zero?

Cities are making plans in readiness. In New York City, as I mentioned, newly built public housing will have electric cooking and many cities in California have adopted similar policies for electric cooking.

In terms of mobility, California has among the world’s largest electric vehicle ownership. In India, Ola, a cab company similar to Uber, has made a pledge to electrify its fleet. The Indian government has set targets for electrifying its vehicle sector, but then cities have to think about where to put charging stations.

A lot of cities have been doing low carbon transitions, with mixed success. Low carbon means reducing carbon by 10 to 20 percent. Most of them focus entirely on efficiency and energy conservation and will rely on the grid decarbonizing, but that’s just not fast enough to get you to net zero by 2050. I showed in one of my papers that even in the best case, cities would reduce carbon emissions by about 1 percent per year. Which isn’t bad, but in 45 years, you get about a 45 percent reduction, and you need 80-plus percent to get to net zero. That means eliminating gas/fossil fuel use in mobility, heating and cooking, and creating construction materials that either do not emit carbon during manufacturing or might even absorb or store carbon.

That’s the systemic change that is going to contribute to getting to net zero, which we define in our Annual Review of Environment and Resources paper as at least 80 percent reduction. The remaining 20 percent could be saved through strategies to capture and store carbon dioxide from the air, such as through tree-planting, although the long-term persistence of the trees is highly uncertain.

Are there notable case studies of cities you could discuss?

Denver has been covering the most sectors. Some cities cover only transportation and energy use in buildings, but Denver really quantified additional sectors. They even measured the energy that goes into creating construction materials, which is another thing the net zero community needs to think about. Net zero is not only about what goes on inside your city. It is also about the carbon embodied in materials that you bring into your city and what you export from your city.

Denver was keeping track of how much cement was being used, how much carbon dioxide was needed to produce that cement, called embodied carbon; what emissions were coming from cars, trucks, SUVs and energy use in buildings. They measured all of this before they did any interventions.

The city has also done a great job of transitioning from low-carbon goals (for example, a 10 percent reduction in a five-year span) to deep decarbonization goals of reducing emissions by 80 percent by 2050. During their first phase of low-carbon planning back in 2010, they counted the impact of various actions in each of these sectors to reduce greenhouse gas emissions by 10 percent below 1990 baselines, through building efficiency measures, energy efficiency and promotion of transit, and were successful in meeting their early goals.

Denver is also a very good example of how to keep track of interventions and show that it met its goals. If the city did an energy efficiency campaign, it kept track of how many houses were reached, and what sort of mitigation happened as a result.

But they realized that they’re never going to get down to net zero because, while efficiency and conservation reduce gas use for heating and gasoline use for travel, it cannot get them to be zero. So in 2018, they decided that they’re now going to do more systemic changes to try to reduce emissions by 80 percent by 2050, and monitor them the same way. This includes systemic shifts to heating via electric heat pumps and shifting to electric cars as the electric grid also decarbonizes.

So it’s counting activities again: How many electric vehicles are there? How many heat pumps are you putting into the houses that can be driven by electricity rather than by burning gas? How many people adopt these measures? What’s the impact of adoption?

What you’re saying is that this accounting before and after an intervention is put in place is very important. Is it very challenging for cities to do this kind of accounting?

It’s like an institutional habit — like going to the doctor for a checkup every two years or something. Someone in the city has to be charged with doing the counting, and so many times, I think it just falls off the radar. That was what was nice about Denver — and we worked with them, gave them a spreadsheet to track all these activities.

Though very few cities have done before and after, Denver is not the only one. There are 15 other cities showcased by ICLEI, an organization that works with cities to transition to green energy.

I have worked with ICLEI-USA to develop protocols on how to report and measure carbon emissions. One of the key questions is: What sectors are we tracking and decarbonizing? As I mentioned at the start, most cities agree with tackling energy use in transportation and building operations, and greenhouse emissions from waste management and wastewater. ICLEI has been a leader in developing accounting protocols, but cities and researchers are realizing that cities can do more to address construction materials — for example, influencing choice between cement and timber, which may even store carbon in cities over the long term.

I serve on ICLEI-USA’s advisory committee for updating city carbon emission measurement protocols, and I recommend that cities also consider carbon embodied in construction materials and food, so that they can take action on these sectors as well.

But we don’t have the right tools yet to quantify all the major sectors and all the pathways to net zero that a city can contribute to. That’s the next step in research: ways to quantify all those things, for a city. We are developing those tools in a zero-carbon calculator for cities.

How Office Owners are Achieving Net Zero Goals

Posted on November 9, 2021November 9, 2021 by abrahamwien18

Both tenants and investors are increasingly focusing on office building’s carbon footprints when considering new deals.

By: Patricia Kirk
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As the push to become carbon neutral accelerates globally, there is increasing pressure on office building owners to implement changes to accommodate those goals, including by making their buildings more energy efficient, using sustainable building materials, reducing waste and improving water systems. Some 105 big companies, including Amazon, Microsoft, Unilever, and BlackRock among others, have pledged to be carbon neutral by 2040, with additional firms promising to reduce carbon emissions by 2030. More than 100 countries, including the U.S., have pledged to become carbon neutral by 2050.

“A future where businesses are taxed on their carbon emissions could be close at hand,” said Drew Shula, founder and CEO of The Verdical Group, a Los Angeles-based green-building consulting firm.

California has already passed legislation requiring new and significantly renovated commercial buildings to be carbon neutral by 2030. Additionally, New York City’s Climate Mobilization Act (CMA) includes Local Law 97, which impacts all buildings over 25,000 sq. ft. and calculates carbon intensity for buildings on a per square foot basis, assigning limits to intensity beginning in 2024. Buildings that exceed that limit will be fined $268 per ton of carbon, notes Meadow Hackett, manager for sustainability and KPI services at consulting firm Deloitte.

She notes that many office REITs are planning carbon neutrality strategies to avoid penalties at their New York City properties, and companies are making capital allocation decisions around energy efficiency based on penalty avoidance.

Green building experts acknowledge that a net zero mandate would present a challenge for office building owners/investors, but note that it may not be as daunting as they might perceive.

“Any existing building’s carbon emissions can be reduced, and the first step is to understand its current level of performance,” says Elizabeth Beardsley, senior policy counsel for the U.S. Green Building Council (USGBC). She adds that this requires metering and reviewing utility bills and any other available building performance data that can help identify areas in need of increased operational efficiency and performance.

Once this assessment is completed, existing building owners and operators should develop a strategic action plan aimed at reducing annual building greenhouse gas emissions, Beardsley says. “The action plan can help owners to develop an ‘optimal path’ forward via the evaluation of alternative scenarios to assess opportunities for system upgrades, efficiency improvements, renewable energy generation and/or procurement, and calculate associated costs for each scenario.”

According to Rielle Green, manager of energy & sustainability with CBRE Property Management, which manages 2.7 billion sq. ft. of commercial real estate globally, there is no one-size-fits-all solution for getting to net zero. “Every property is uniquely built with different operating systems and located in different areas with different climates.”

CBRE property managers work with clients to determine which solutions make sense, which may include installing solar panels to reduce carbon dioxide emissions and energy consumption, smart building technology to monitor energy usage, LED lighting or green roofs.

Beardsley adds that owners could lower a building’s carbon footprint by encouraging tenants to commute by walking, biking, public transport, ride-sharing and carpools. This might involve providing a shared bicycle system or membership in a micro-mobility fleet; contributions for public transportation passes; car-sharing memberships; and on-site electric vehicle (EV) charging stations.

Beardsley also notes that conservation and recycling are other important elements for reducing a building’s carbon footprint. “Reducing a building’s water consumption reduces associated energy loads for water provision and wastewater management, as potable water treatment, distribution and use are highly energy-intensive,” she says.

She offers case studies to illustrate how existing buildings achieved LEED Zero certifications.

The Los Angeles Department of Water & Power, for example, began reducing the footprint of its 17-story, 55-year-old, all-electric John Ferro Building in 2013 with a suite of energy efficiency measures, including lighting retrofits, chiller and fan system upgrades that earned the building’s initial LEED certification in 2015. The following year, the building, which houses LADWP’s 11,000 employees, recertified LEED Gold and in September 2019, it became the first building in California to achieve LEED Net Zero Energy.

Another example is the historic headquarters of Entegrity Partners, a sustainability and energy services company specializing in the implementation of energy conservation and renewable energy projects, which became the first LEED Zero-certified project in the U.S. in 2019 and the second in the world. The building, which achieved LEED Platinum for New Construction, was also awarded Zero Energy certification by the International Living Future Institute.

Entegrity began devising a plan to retrofit its 13,342-sq. ft. Darragh Building to net zero energy in 2016. Initial strategies employed included all-LED lighting, dynamic self-tinting glass, operable windows and doors for natural ventilation in the summertime, and occupancy sensors. The renovation also used locally-sourced materials when possible; preserved daylighting; and installed lighting controls, high-efficiency plumbing fixtures, and native landscaping.

Office buildings with high performing environmental improvements also command a rent premium, according to Beardsley, and trade at higher values than traditional buildings because they offer savings in operational costs. She cites research that indicates tenant were willing to pay $0.75 per sq. ft. for space in a LEED-certified office building compared to a non-LEED certified one.

Additionally, the U.S General Services Administration (GSA) released a 2018 study on the impact of high-performance buildings that quantified their benefits compared to their legacy building counterparts in the GSA’s portfolio. The study found that the upgraded buildings delivered greater cost savings and tenant satisfaction were deemed, therefore, a less risky investment than traditional buildings.

Shula suggests that Blackrock, the world’s largest asset manager, is a great example of this preference for more environmentally sustainable building. The firm committed to net zero for its own operations and is making being carbon neutral the central focus for its more than $8 trillion in assets under management.

Hackett, notes that sustainable swaps and building retrofits are already common in existing buildings to meet carbon neutrality goals. Landlords are deploying more efficient technology, such as occupancy light sensors, LED lighting, and power management software to control HVAC systems.

“Investors are more in tune with how their buildings are performing when it comes to sustainability and ESG today than a decade ago,” adds Green. She notes that sustainability has definitely become a selling point because potential tenants want to know how their buildings are performing in comparison to other buildings in the market.

Meanwhile, “[Institutional] investors are placing ESG, and climate change in particular, central to their investment strategies.”

Hackett notes, for example, that members of Net Zero Asset Owner Alliance, which represent roughly $5 trillion in assets under management, have pledged to transition their investment portfolios to net zero emissions by 2050.

The cost for upgrading existing buildings to achieve net zero depends on many factors, but the building’s age and relative inefficiency are key determinants, Beardsley says. She also notes that the building’s size, shape, and location may limit its capacity to generate on-site renewable energy.

However, “You don’t need to get to zero carbon all at once,” says Shula. “Create a plan to achieve carbon neutrality by 2030, then work backward to today to determine what steps to take first.”

For example, as building equipment reaches end-of-life, it should be replaced with more efficient, all-electric equipment and appliances to enable the reduction of the carbon footprint, he notes.

Getting ground-up buildings to net zero, on the other hand, adds a cost premium of zero to 1 percent when designed and developed as a high-performance building from the start, according to a 2019 USGBC report, The study also noted that operational savings recoup any incremental costs for getting to net zero in a relatively short time, with return on investment for both existing and new office buildings beginning in as little as a year.

Emma Hughes, a LEED project manager with USGBC, notes that with today’s tools, technology and knowledge all new buildings can be designed and constructed to highly efficient standards and achieve net zero energy during the construction process via integration of renewable energy generation and/or procurement.

Net-Zero Energy Homes Pay Off Faster Than You Think—Even in Chilly Midwest

Posted on November 14, 2019 by abrahamwien18

By Dan Gearino
View the original article here.

As solar and heat pump prices fall, these highly energy-efficient homes are paying for themselves faster. Here’s how they work and why they’re spreading northward.

Home-builder Bill Decker explains some of the techniques used to create highly energy-efficient homes in chilly southeast Michigan. New research shows that the extra cost of making a home net-zero energy can pay for itself in under a decade in Detroit and 11.4 years in Chicago. Credit: Dan Gearino

LAMBERTVILLE, Mich.—On a drive down a country road, builder Bill Decker gives an off-the-cuff seminar about energy efficient homes.

He shifts from carpentry to electrical engineering, and then to theology—his belief that his faith compels him to take care of the earth. Every few minutes, he pauses and points out a house his family-owned company has built.

He has been in business since 1981 and only now is his industry beginning to grasp something he has been arguing for a while: Net-zero-energy homes—homes that are so efficient a few rooftop solar panels can produce all the electricity the home needs—can be built almost anywhere, even in places with brutal winters.

His case is bolstered by a recent report from the Rocky Mountain Institute showing net-zero energy houses can make financial sense in much of the Midwest as costs for some of the key components fall. The initial extra costs of making a new home a net-zero energy home pay for themselves through energy savings in less than a decade in both Detroit and Columbus, Ohio, and in less than 14 years in most of the 50 largest U.S. cities, the report says.

At the forefront are custom builders who specialize in efficient houses and helped to create this market, people like Decker, 79, whose southeastern Michigan company, Decker Homes, is just across the state line from Toledo, Ohio.

“It isn’t just energy efficiency we’re talking about here,” he says. “It’s the whole world. We’re talking about climate change.”

Indeed, housing is responsible for about 20 percent of U.S. greenhouse gas emissions, including its share of power plant emissions.

Yet his sales pitch is largely about comfort. An energy efficient house doesn’t have chilly drafts, and the temperature varies little from room to room, and those are things that appeal to most people, he says.

‘It’s the Little Things that Add Up’

Decker parks on the dirt driveway of a house in progress as a light rain turns to snow flurries. In a living room that is studs and bare wood floors, he notes the features that make this house highly energy efficient. The key is making insulation an essential part of construction.

Decker walks to the corner of the room and points out an opening of several inches between studs to allow for easy placement of insulation. Builders call this a “California corner,” which is an alternative to a typical corner design that is much more difficult to insulate.

“It’s little things that add up,” he says.

Zero-energy homes start with well-sealed and well-insulated attics, walls and basements or slabs. They often use triple-pane windows, especially in places with cold winters. Inside, energy-efficient appliances, highly efficient LED lighting and smart thermostats help avoid energy waste.

Their designs often take natural lighting into account, too, and position windows and overhangs for additional solar heating in the winter and shade in summer. Since the homes are sealed to avoid letting cold or hot air in—and cool or warm air out—they also have ventilation systems customized to maintain comfortable circulation.

Decker recently completed his first house with an air-source heat pump, which is less expensive than geothermal heat or other electric options. In cold weather, the system extracts heat from the outside air and uses it to maintain a comfortable indoor temperature. In warm weather, the process is reversed, with the system gathering heat from inside and transferring it outside.

He is starting to use air-source systems because newer models work well in below-freezing temperatures, which was not the case just a few years ago. Heat pump advancements are one of the main factors making highly efficient homes more affordable in many colder climates.

This is in addition to a cost factor that affects all climates: Rooftop solar prices have plummeted in recent years and are projected to continue doing so. That is true of battery power storage as well.

In Detroit, Net-Zero Pays for Itself in 9 Years

The costs and benefits of building net-zero houses vary widely in major cities, ranging from San Francisco, where the benefits would cover the costs in eight years, to Philadelphia, where it would take about three times as long, according to the Rocky Mountain Institute.

The largest savings tend to be in cities with high electricity rates and older building codes.

The key point is that energy efficiency pays for itself, which is not the case for many other major expenses in a house, said Jacob Corvidae, principal at Rocky Mountain Institute, a research nonprofit that focuses on clean energy.

“Zero-energy homes are actually affordable,” he said. This is important because many consumers, builders and policymakers are reluctant to consider zero-energy homes because of the perception that costs are prohibitive, he said.

In Detroit, for example, a 2,200-square-foot net-zero energy house would cost $19,753 more than the same house with no solar and typical efficiency. The energy-bill savings would be $2,508 in the first year, and the solar and efficiency costs would pay for themselves in about nine years with inflation and other changes taken into account.

Bill Decker’s son, Dale, shows some of the construction methods used to insulate and seal a highly energy-efficient home against air leaks and energy waste. Credit: Dan Gearino

The Midwest is well represented among cities with short payoff periods. Detroit is second in the report. Columbus ranks fourth, with a payoff of less than 10 years. Chicago ranks 10th and Indianapolis is 12th, with payoffs of about 11 years and 12 years, respectively.

Detroit has high annual savings in part because the city has some of the highest electricity rates, Corvidae said. Columbus’ high savings are in part because the city has an older building code, so standard houses do not have high efficiency standards.

A home with all the energy efficiency attributes of a net-zero energy house but not the solar panels will save customers money even more quickly, the report notes, though it doesn’t provide all of the climate benefits. In Detroit, a “net-zero-energy ready” house without solar would cost $1,574 more than a typical house and would pay for itself in less than two years. After that, the investment means hundreds of dollars in savings for the homeowner every year.

New California Mandate Gets Close to Net-Zero

Net-zero energy homes are a fraction of 1 percent of new housing being built, but their share is growing. Builders completed 13,906 net-zero housing units last year in the United States and Canada, a 70 percent increase from the prior year, according to a report by the nonprofit Net-Zero Energy Coalition.

California was the leader with more than 5,000 units, five times more than runner-up Arizona, where the Rocky Mountain Institute report shows net-zero homes in Phoenix can cover their costs in 11 years.

California’s lead is likely to grow because of a state building code update that takes effect in 2020 and will require solar panels on most new housing and have strict efficiency standards, the first state to do so. The code falls short of a mandate for net-zero energy housing, but it comes close.

Meanwhile, some of the country’s largest home builders, such as PulteGroup and Meritage Homes, are taking steps to offer net-zero energy options. In Cortez, Florida, Pearl Homes is building a zero-energy community that also incorporates energy storage and electric vehicle chargers.

The corporate moves are tied to consumer demand and because energy efficiency is becoming more affordable, said Ann Edminster, a consultant and architect who works with the Net-Zero Energy Coalition.

“We’re starting to see the tip of that iceberg, and when it really hits, it’s going to be huge,” she said.

Bill Decker thinks many more people would want an energy efficient house if they only had someone to explain the benefits. In his part of the world, that someone is him.

“It’s creating value, saving money, helping the environment,” he said. “In the end, you say to yourself, ‘Why would you do anything else?'”

Florida development brings net zero homes to the mass market

Posted on November 14, 2019 by abrahamwien18

A 148-home central Florida development may be the sign that net zero living has gone mainstream.

View the original article here.

Long-time builders Greg and Sue Thomas have opened Green Key Village, a 78-acre net-zero home development in Lady Lake, Florida, about 50 miles northwest of Orlando. The homes will be certified under the Florida Green Building Coalition, and one model home has already achieved a platinum rating, Thomas said. The homes will also be Energy Star and Department of Energy Zero Energy Ready Home. Each home will be HERS rated, and the goal is to achieve a HERS index of 50-55 prior to renewable energy installation. An average code built home has a HERS Index of 100.

Also, the homes have earned the Florida Friendly Landscaping silver designation in recognition of resource-efficient landscape design.

To help them with the challenge of selling a net-zero community, the Thomas’s brought on Tony Richardson to help them sell. With more than 30 years of experience in green home building and marketing, Richardson is a Green Designee of the National Association of Realtors, and a USGBC Green Associate.

Green Key Village is the first residential neighborhood in the nation designed using software offered by Ekotrope that was developed at the Massachusetts Institute of Technology. The software analyzes 10,000 variables to give designers data to compare each component of the home by its cost and energy efficiency. They can evaluate wall thickness, window size, insulation depth and every other aspect of the home. The development offers eight floor customizable plans in one- and two-story options. ranging from $318,000 to $414,000 and home sizes ranging from 2,755 square feet to 3,637 square feet.

Thomas said the Ekotrope analysis helped them make cost/benefit trade offs. For example, the home uses a 15-SEER rated air conditioning unit because the payback for a higher rated unit would have been longer than the life of the product. The analysis also showed that with the high-efficiency HVAC and a heat pump hybrid water heater, one of the most efficient on the market, the HVAC heat pump had to be only a 2.5-ton capacity in the 3,000-square-foot model home.

In an exclusive interview with ProudGreenHome.com, Greg and Tony talked about the challenges of presenting high performance, net-zero living to a mass-market real estate environment.

What was your vision for the community?

Greg: Where we live there’s a house with a big front porch and every afternoon the neighbors gather on that porch. In my mind, if all our houses had front porches I think it would be a great gathering place for neighbors to meet and fellowship. We wanted to build that kind of a neighborhood.

My dad was a builder, and I’ve been a builder for 30 years. It’s always been concrete block and stucco. That’s worn out. I said, let’s look for something different. We went to the coast, and saw houses with bright colors with lap siding, a metal roof and big windows covered with Bahamas shutters.

We put it out here in the middle of Lady Lake and have a great looking subdivision that isn’t made from a cookie cutter.

So that was our goal. We wanted to combine old Florida charm and new green living. I think we’ve hit it pretty good.

What are some of the challenges in communicating a high performance home to the general buyer?

Greg: I like to give them a brief overview and then back off until they ask more questions about it. It overloads them; actually, their eyes glass over when they’re just looking for the granite countertops.

It’s hard not to load them up with all the information, but we’ve spent so much money on this technology you hate to not to.

What makes your homes perform so well?

Greg: We used Ekotrope software to optimize the house design and balance all the HVAC loads, insulation and so on. We use open-cell spray foam on the underside of the roof deck, and the mechanical room is in the attic but it’s in conditioned space in the attic under the foam on the roof. Depending on the floor plan, the room can be 200 square feet to 500 square feet.

The GE heat pump water heater is in the room, and with it being a heat pump it keeps that area cooler and drier as it operates. It’s like having a dehumidifier up there. The manifold block plumbing system originates there too, right next to the water heater. And the HVAC ductwork is in there, too. It all works together.

It’s a nice attic room with stair leading to it homeowners could use for storage as well.

What are some of the green aspects of the home?

Icynene open-cell spray foam insulation
Advanced framing techniques
GE heat pump water heater
Two Panasonic energy recovery ventilators
Amana 15 SEER heat pump
Double pain Low-E windows from YKK
LED & CFL lighting
Energy Star appliances
WaterSense fixtures

What is the result of your green building strategies?

We cut the air conditioning load almost in half by going with the open cell spray foam insulation on the walls and ceiling. With the A/C, water heating, lighting and all the appliances are Energy Star rated, we’ve brought down our power usage on this house. Here an average house uses 1,500-1800 kilowatt/hours per month, and we’re down to less than 1,000. Then we take care of that with the solar panels.

What is your water conservation strategy?

As part of the Florida Green Building Coalition certification, we are certified to have less than a half-gallon of water in the lines. We use a maniblock plumbing system and PEX tubing.

Are you using advanced framing techniques, and how does that work with the wind load requirements?

We use regular 2×4 framing and what’s referred to as the “California corner,” two studs in the corners and we use horizontal blocking that gives you a nailing surface. You have to re-train your framers and help them remember that you can’t load up these corners with studs. We’ve heard of people going 24-inch centers but we haven’t gotten brave enough to do that.

All our homes have to be certified to meet 130 mph wind load. We use a solid sheathing with 4×10 OSB that helps fight uplift. Also the tie downs and anchors come into play to meet the wind load regulations.

Is there a price premium on the all the green attributes of the homes, and how do you communicate that to the buyers and the financial community?

From the water heater to the insulation the lighting to bath fans, to the ERV and solar panels, when you add all that up, the difference is $35,000 to $40,000 of additional value to the home.

We have prepared an addendum for our contract, because when you attach an addendum for the contract, the appraiser for the bank has to look at anything attached to the contract. For each model we have addendum that shows our cost for open cell spray foam insulation so and compare that to the traditional batt foam insulation on concrete block.

That also gives the homebuyer the documentation they need to apply for their solar tax credit.

How do buyers respond to the idea of a paying a premium for a high performance home?

We tell them, compared to an average $200 a month power bill, with the lower utility costs of these houses, you have $42,000 to $43,000 more power buying over the life of the mortgage. Whether you’re paying cash or using a mortgage, your overall buying power is that much more.

The math works. And you get a much a much healthier house. With the no-VOC paints, the low-VOC carpets and cabinets, your home is healthier. The ERVs are bringing in fresh air 24 hours a day.

Tony: These homes are priced very comparably to homes of similar size if they they had the same quality as these homes.

We can show on a cash-on-cash basis, they’ll be not spending more money but making money starting the first month and every month thereafter. There’s no flim flam here; it’s the truth.

Photos courtesy Green Key Village LLC.