$188,000 homes in Colo.
Inspired by what he saw, Walker decided to replicate the building. With the help of students from a University of Denver work-study program, his company was able to complete two experimental net-zero homes -- the second of which recently sold for under $190,000.
Having perfected its net-zero design, Oakwood plans to start marketing more of the homes in Colorado later this year. Each four-bedroom house will feature rooftop solar panels, a high-efficiency tankless water heater, super-insulated windows and airtight construction.
With a $188,000 price tag -- only $9,000 more than Oakwood's Energy Star version of the same house -- it could soon be the most affordable net-zero home in the country. With about $750 in energy savings predicted annually, homeowners are expected to see a full return on their investment in less than 12 years.
"We've hit a price point that no one else has been able to hit in our marketplace," says Walker, and "we've gotten a lot of great response."
At least a dozen other U.S. commercial homebuilders have begun to offer net-zero residences. The Los Angeles-based company KB Home recently introduced a net-zero option for its houses in parts of Florida, Texas, Colorado and California. Another company, Nexus EnergyHomes, is building 59 duplex units in Frederick, Md., and 14 additional houses near the Chesapeake Bay. The duplexes are about 1,700 square feet -- the same size as Oakwood's homes -- and sell for $275,000 and up.
Each commercial and residential building employs a unique blend of renewable energy and architectural design to reach net zero, but there are some characteristics that nearly every structure shares. Most use solar panels to achieve the bulk of their power and have numerous windows to minimize the need for artificial light. Tight insulation and low-energy appliances are also key elements. Paradoxically, most buildings actually receive electricity bills -- though not very many.
This happens because a net-zero building may need to draw electricity from the grid to power its lights at night, for example, then returns that energy the next day, when its solar panels are most efficient. Likewise, residents may have to pay for heating costs in the winter, but in the summer they would receive a check for their overflow of energy.
Transitioning into a net-zero world without electric bills may sound like a no-brainer, but the technology still faces significant obstacles.
Cost and space remain drawbacks
The success of a building depends largely on the people who use it. If occupants aren't committed to reducing their personal energy use by shutting windows and turning off appliances, a net-zero structure can easily lose its status, becoming just another "efficient" building.
Some areas are also poorly suited for net zero. A building needs enough sunshine to power its solar panels, and that's not always possible in a densely populated city, where tall buildings can cast shadows onto shorter ones. It's also tough to keep structures cool in very hot and humid climates, like in the Southeast, says Hobart. But most experts agree the main barrier is still the price.
"Most building owners aren't going to add 1 percent to their costs. They are just going to build to code," Hobart says. And retrofitting existing buildings to be net zero becomes even costlier.
"When you put all the pieces together, the payback becomes so great that it doesn't make sense," Walker says of the retrofits. Aside from solar panels, thicker windows, and a new heating and cooling system, buildings often need far more insulation than the walls can hold. That requires shrinking rooms or expanding the exterior, which isn't cheap. Walker believes net-zero upgrades are for people who "are less worried about payback and more concerned to do something good for the environment."
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18 Comments
Add CommentThe potential of these approaches is just beginning to be tapped. Net zero energy buildings could eliminate %40 of our energy consumption and possible %50 of our carbon emissions if they become an industry-wide practice.
Reply | Report Abuse | Link to thisThe article mentions the difficulty of implementing net-zero energy construction: most builders only build to code. This is because they don't see the benefits of energy efficiency, the owners they sell to do. This is why we need to improve the code and incentivise going beyond the code.
Consequently, renters and landlords also do not see the proper incentives to implement efficiency and renewable energy because of who pays the energy bills and who actually owns the property. Think about that for a moment.
Anyway, if these homes can sell for under $200K, that's great. If they're a little more pricey, I'd rather see money going into these efficiency / clean energy options instead of more square footage to store our cheap, plastic junk imported from China.
"I'd rather see money going into these efficiency / clean energy options instead of more square footage to store our cheap, plastic junk imported from China."
Reply | Report Abuse | Link to thisBut... but... who will I be without my cheap plastic junk and how will I hold at bay the emptiness of the universe if I can't be at one with all the other owners of cheap plastic junk? The horror! /derision
Net-zero energy is easy for small houses and buildings with only LED lights, TV, computer and solar-heated water.
Reply | Report Abuse | Link to thisNet-zero energy is hard for tall buildings because they have low roof to floor area ratio. Solar panels are efficient only on roof and east-west sides of building. Unless you put a large wind turbine on top of the building.
Net-zero energy is also hard in cold places (< 0C) where you need heater. Unless you burn firewood (that's renewable)
"Just a joke, hopelessly impractical. A recipe for TOTAL ECONOMIC COLLAPSE."
Reply | Report Abuse | Link to thisExaggerate MUCH?
Now you're just being silly. Move along people, nothing to see here. Report abuse and ignore.
Reply | Report Abuse | Link to thisYou're building a strawman argument. As long as the grid is there as backup, the Net-Zero building doesn't need to produce hydrogen. Since solar power is cyclic and easily predictable on a monthly basis, all you need to do is power the building during the night like we always do and have the Sun take care of the difference between daytime and nighttime demand. Since the homes are so energy efficient, the difference is not very large AND the nighttime "baseload" demand is much lower than most structures built today.
Reply | Report Abuse | Link to thisUsing a combination of responsive natural gas plants, wind farms, other renewable energy and storage (compressed air underground, pumping water back behind a dam when demand is low, idle electric vehicle batteries, or whatever makes sense in the area), we can make a lot of the coal power plants in this country obsolete. This is all we need to do right now because coal power is SUCH a drain on our economy:
http://thinkprogress.org/romm/2011/02/16/207534/life-cycle-study-coal-harvard-epstein-health/
"In terms of human health, the report estimates $74.6 billion a year in public health burdens in Appalachian communities, with a majority of the impact resulting from increased healthcare costs, injury and death. Emissions of air pollutants account for $187.5 billion, mercury impacts as high as $29.3 billion, and climate contributions from combustion between $61.7 and $205.8 billion."
Or see here for another report pointing to a similar conclusion:
http://www.aeaweb.org/articles.php?doi=10.1257/aer.101.5.1649
"Solid waste combustion, sewage treatment, stone quarrying, marinas, and oil and coal-fired power plants have air pollution damages larger than their value added. The largest industrial contributor to external costs is coal-fired electric generation, whose damages range from 0.8 to 5.6 times value added."
If we stop the worst of these pollution sources, then we'll have all this money in the form of higher GDP and lower healthcare costs to solve ANY problems and make our lives MUCH better!
Awesome! Reporting abuse on the hacker's comments gets them removed!
Reply | Report Abuse | Link to thisYou could buy the plastic junk imported from other countries but not China if you want.The The horror derision is you buy the plastic junk imported from China but not other countries.
Reply | Report Abuse | Link to thisI forgot to mention that the German high-efficiency building movement is called Passivhaus. There's some excellent video on YouTube showing how some of their technologies work.
Reply | Report Abuse | Link to thisI'm a building designer hence the moniker "drafter" Net- zero is a nice idea but their are localities where it does not work and that is the problem when you try to make net-zero a building code which California is hoping to get all homes net zero by 2050. This will only be possible if all people move to the valley stay out of the trees or just cut them all down and do not locate above the 2000 foot elevation it can get to cold above that elevation for solar power to keep up and burning wood is banned in some California locations even in the high mountains such as Truckee. As far as someone earlier commentors claiming that builders won't do this unless required to is false I know several owners and builders who try to reach net-zero, often it's just to expensive and those who do reach net-zero normally aren't worried about cost in the first place. I'd like to see a true cost analysis of the energy to produce the products, all the products, that are required things like super insulation and the larger structure and materials to accomadate and even the process of making solar panels there may not be a true net-zero structure it's just relocated or hidden. That I'd like to see because the next house I build for my self I would like to make as close to net zero as possible because no body likes paying to energy company but are we only switching that cost over to a mortgage payment.
Reply | Report Abuse | Link to thisi've read that a net-zero community was built in medicine hat, ab that uses solar and stores heat in an under ground reservoir of water. even though it's very cold in the winter, the amount of sun in southern alberta is crazy
Reply | Report Abuse | Link to this"Net-Zero Energy Buildings" is a classic Straw Man. Virtually ZERO meaning and ZERO relevance. Yeah, so you take an Energy Efficient home - very nice - add a bunch of Solar Panels and subtract Energy Usage of the Home from the Energy supplied to the Grid. Brilliant. How about a building with a Wind Turbine? How about a building with a Wind Turbine 100 yds away? Or one with a big mother Wind Turbine on the property producing 100x the total energy consumed by the home & barn & outhouse all constructed with 2x4 walls and zero insulation - are they now "net energy zero" homes. A net energy zero outhouse? How about someone who owns a small hydro plant supplying 100X the energy there home(s) consume - do they get to declare my home is "net-zero energy"? Why can't I get to declare my home "net-zero energy" because I supply clean, green energy to the Grid, working at a Hydro plant?
Reply | Report Abuse | Link to thisAnd is that Net-zero Energy on a cold year with little sunshine? Or just on a good warm year with lot's of sun? And if I buy shares in a Nuclear Power plant that produces clean, green energy year round, more than my home consumes do I get to declare my home is "net-energy zero".
"Net-energy zero" - another NUTTY Greenie catchphrase that in reality is just an embellishment to hide the INCREDIBLY bad economics of Solar Power. I've repeatedly shown Sault how bad the economics of Solar power are, so new Greenie idea, just combine it with building efficiency in a hope to bury the terrible economics. A huge subsidy for the rich to buy expensive homes while the poor & middle class can't even afford a shack to live in.
How about instead use that subsidy money for a good, basic home for the poor and middle class, with good insulation - like R18, instead of R12, a very tight envelope, double pane windows with southern exposure (in the north), heat exchanger on furnace and air exchange, maybe-maybe Solar Hot water in a good location, and minimum cost construction. Screw the wacky, hyper-expensive Solar Power SCAM & Super-duper extreme Energy Efficiency. What is the marginal cost of Hyper-Super-Duper Energy Efficiency vs just a good basic level of Energy Efficiency? $10k-$40k/kwth avg heat energy savings, I bet. When Nuclear Energy is $0.7 to $2k per kwth avg heat energy. Get 5-60X the Energy Savings by just installing Nuclear Power plants.
It ain't exaggeration. These Whacky Greenie Energy Scams, running $10k - $100k per kwth saved or produced. So per Capita Energy consumption in the USA amounts to an avg of 11 kw. So family of four that's 44 kw. So the Greenie Energy Scams would add $440k to $4.4M per family of four investment, in addition to the already high cost of their home, vehicle and energy consumption. Not feasible, our economy would collapse before we could achieve any significant penetration of these SCAMs. So the Economics are absolutely INESCAPABLE - these Greenie Hyper-Efficiency Solar Powered SCAMs are NOTHING BUT an enormous "Feel-Good" subsidy for the Rich, so they can make the claim "I'm Green".
Reply | Report Abuse | Link to thisGood example of this Greenie Madness, a Rich Homeowner in Colorado gets a $31k subsidy from the Colorado taxpayer in order to install Solar Panels on his roof that puts out an avg of 971 watts! WOW! or $43k per kwavg with latest IEA projected cost for Nuclear in the USA @ $3.8k per kwavg, so 11X the cost of Nuclear - BEFORE your take into account the Shadowing Fossil Fuel power source that accompanies the Solar - paid by the utility customer.see:
http://uvdiv.blogspot.com/2010/09/our-first-year-with-steves-solar.html
You're still building straw man arguments. Take the emotion out of it when you type, please. No one is arguing against improving the energy efficiency of other structures. This article just highlights that if designed properly, it is possible to generate as much energy as a building consumes during the year on-site.
Reply | Report Abuse | Link to this"...You're still building straw man arguments..."
Reply | Report Abuse | Link to thisNope, I ain't. I have no problem with someone building an energy efficient house and putting enough Hydro/Solar/Wind to make it "Net-Zero" Energy, as long as they pay for it 100% themselves, since it is a useless waste of money from the public perspective. And ANY HOME can be made "Net-Zero" Energy just by adding enough Solar Panels or Wind Turbines, you don't need an Energy Efficient home, so "Net-Zero Energy" is THE REAL STRAW MAN.
Energy Efficient Housing has merit, I wish instead of supplying stupid Religious Greenie Code Words or Icons like "Net-Zero Energy" they would actually give hard data on cost/benefit analysis of each aspect of Energy Efficient housing. The added Solar PV is entirely separate & IRRELEVANT to that important analysis. I have analyzed Solar PV here and elsewhere and shown it to be FAR from economical, and FAR from being an Energy Solution to the rapidly approaching Peak Oil/Global Warming Crisis. So tacking on to Energy Efficient housing as another DEVIOUS and COWARDLY Greenie way to HIDE the true costs of Renewable Energy. Quite simply despicable. Just like their Renewable Portfolio Standards RIP-OFF. Shoving their Religion down peoples throats.
Large (and tall) zero net energy buildings are quite possible. See SOM's Pearl River Tower in Guangzhou, China. Completed recently, it is a 71 story tower designed to be ZNE. It has VAT wind turbines, battery storage, fuel cells, solar PV and leading edge energy efficiency design features. See: http://www.som.com/content.cfm/pearl_river_tower
Reply | Report Abuse | Link to thisDevelopers, architects, and builders are beginning to realize that Net-Zero Energy Building (NZEB) is central to the future of our industry. Currently, there isn’t a definition. Furthermore, the measuring science doesn’t exist. The National Institute of Standards and Testing has been conducting conferences to flush out a system. One idea is "Whole Building Metrics". Consider the holistic approach and reach beyond NZEB to Zero Energy Concept Building (ZECB). ZECB is a step forward because ZECB includes technology to purify waste water and improve indoor air quality by harnessing the power of Mother Nature to replenish these resources. A draft of a definition for Zero Energy Concept Building (ZECB) is on a website developed for this purpose. Links are provided to support conclusions backed up by 3 years research. There are two pages on the site; the HOME page illustrates an example of a ZECB and the second page is a draft of a definition for ZECB. Here's the link
Reply | Report Abuse | Link to thishttps://sites.google.com/site/zeroenergyconceptbuilding/home
Net zero is just another despicable way sleazy Big Oil/Greenies try to hide the outrageous cost of Solar power. Try to bury the cost into a buildings cost and legislate Solar Power by integrating into a building cost.
Reply | Report Abuse | Link to thisUnderstand this, there is energy efficient building construction, with passive Solar heating, Heat pumps, good insulation, efficient lighting etc. Very desirable. Then there is the energy supply of the building, an ENTIRELY separate issue. It costs a certain amount to supply energy to a building, you want to find the most cost effective way to supply that energy, and if you want zero emissions energy then THE ONLY WAY to calculate that is counting the moment by moment power consumption of the building. It is dishonest, false and deliberately misleading to try to add the total energy dumped to the grid - the total energy consumed by the building and claiming the building didn't consume any energy or the building didn't produce any power plant emissions - wrong it did.
So Building Energy Efficiency is one issue. Building Energy supply is another ENTIRELY SEPERATE issue. And the cheapest way to make a building NO EMISSIONS is to supply its energy from a Nuclear Power plant.