Interest in greener buildings has skyrocketed in the last decade. From commercial properties taking steps to add green spaces on their rooftops to home builders and do-it-yourselfers making residential buildings more sustainable, the push toward greater energy efficiency in construction continues to gain momentum.....albeit at a pace far below the optimal.
Particularly with regard to home building and renovation, I frequently talk with people who want to turn their houses into net-zero-energy (NZE) or near-NZE living spaces, meaning that over the course of a full year, the residents consume no more energy than the home itself produces. Sounds tough, right? Maybe even downright impossible, especially for residents living in colder climates that demand home heating for six or more months each year?
Take it from me, I'm living proof that an NZE home is possible, even for someone who lives in the unpredictable climate of upstate New York, where temperatures can drop to 10-below zero in January and soar to over 100 in August. And as someone who moved here from the southwest, I wondered what kinds of challenges these seasonal changes would present someone aiming to achieve high energy efficiency in their home.
Because I've had a lifelong interest in sustainability, I wanted to build a house that reflected my beliefs. Fortunately for me, I found an innovative, skilled builder named Anthony Aebi who had a similar dream: to create a repeatable, cost-effective approach to achieving zero energy in a development he's creating called Green Acres in New Paltz, NY. I eagerly signed up to become the first resident. Green Acres now has five occupied homes and we can find no other examples in the world of a NZE development that has proven its claim.
So how do you get started in building an NZE home, with or without a committed builder? First, there are several misconceptions about projects like this. In particular, many believe it's an enormously expensive endeavor. That's simply not the case.
In our experience, we've found that it cost only 10 percent more to include the many energy efficiency features, while the payback period will be seven to 12 years, depending upon the price of heating oil. Added to this, based on recent sales of homes in the development, I strongly suspect that if I were to sell, I would recover most, if not all, of these additional costs -- even in this housing slump!
To help defray the costs, there are a number of federal and state incentives that can help as well. Take a look at the U.S. Department of Energy website to learn more about currently available tax credits and rebates.
Another common misconception is that adequate commercial technologies simply do not exist. As Anthony can testify, this also is a myth. Many large home appliance companies, such as WaterFurnace, are producing wonderful systems that are reasonably priced and perform very well.
My home combines a geothermal heating and cooling system (HVAC) along with solar panels, superior insulation and sealing. I also recover energy that would normally be lost in air exchange through a heat recovery ventilation system. My house is located about 90 miles north of New York City. Because of its latitude and weather conditions, this region isn't the easiest place to generate solar energy. Frankly, NZE is much easier to achieve in places like California, Arizona or throughout the south; so if we can do it here, it can be done virtually anywhere!
Now this is where taking a greener approach gets interesting. I pay $16 a month to the local utility here in New York in order to stay connected to their electrical grid. And last year, the utility actually paid me for the energy I sold back to them! Check out some of the features from my NZE home, then read on for some tips to put to use in yours:
Here are some more details on the specific features I've built into my NZE home. Perhaps you're interested in incorporating some or all of these into your home building or renovation project.
The only way we as a country are going to get away from our fossil fuel dependence is to tackle the biggest areas of energy waste. Buildings (commercial and residential) are well established as the single largest consumers of energy worldwide. Moving toward the zero-energy model is a great step in the right direction. I live in a true dream house, and it didn't require a huge trade-off to maintain environmental stability. I hope this inspires others to follow my lead.
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Check out the contest --> http://www.nesea.org/inspirationawards/zeroenergy/
We just installed our solar yesterday and became America's oldest and Michigan's first net zero house. It's also the first net zero restoration in a historic district. Here's some photos of our 110 year old net zero home:
http://picasaweb.google.com/greenovationtv/SolarInstallAmericaSOldestAndMichiganSFirstNetZeroHouse102110842PM?feat=directlink
Facts about the house: www.MissionZeroHouse.com and www.Greenovation.TV
My husband and I are in the planning stages for an environmentally friendly, and hopefully net zero, new "old house." Its interior/exterior will look as if built in 1820 and its innards will be strictly 21st century.
We have one significant advantage in that we live in South Carolina.
Do you have a website which explains your building methods in detail? Is the insulated concrete used for walls, pad or both? We are looking for a construction method which will give the appearance of at least 1 foot thick exterior walls which will makes deep enough window embrasures to allow historically correct solid interior shutters as well as exteriorn--not just for looks either, as we have designed them with an insulated core.
What is the R factor of the foam insulation used on your attic roof? Do you insulate the attic floor as well? If so what do you use and what is the R factor?
Also, what, if any, savings have you experienced by planting deciduous trees or other passive solar projects?
Hats off to you for tackling a retrofit so aggressively. That's fabulous and in many ways much harder to pull off than new construction, of course. All the best in your effort, and please keep me informed of your progress.
Let me now answer your questions:
1. Yes, you can learn more about the building methods at: www.greenacresnewpaltz.com
2. The insulated concrete forms (ICF) are just for the walls, but they extend all the way from the foundation to the very peak of the roof. My walls are quite thick at about 1 foot, providing nice fat sills that allow me to accumulate too much junk. :(
3. My builder used sprayed icynene foram, about a foot thick, completely enveloping the rafters. The foam is R-38. He could have gone higher with closed (versus open) cell foam, but he felt more comfortable with the breathability of the open cell, esp given that the wooden rafters are smothered in it.
4. It's impossible for me to quantify the savings that have resulted from my choice to place the majority of the windows on the south side. I can tell you experientially that it has a tremendous affect on sunny days in the winter. I wish I had more hard data to know.
So please keep the questions coming and your NZE journey going strong!
We will be using architectural features suitable for our area like 12' ceilings, wraparound porches and center hall floorplan upstairs and down. All the room entry doors line up with windows for perfect cross ventilation. Our ancestors knew a thing or two about building we forgot when air conditioning became readily available.
We are building on a 5 acre lot allowing us to have a kitchen garden which will supply most of our fruit and vegetable needs.
Since we are staring down the barrel of Social Security, this is our retirement project. We don't like golf, our three dogs make it difficult to travel and my husband's avocation is historic carpentry.
We call the house "Green Grove" and are hoping that publicizing it will make sustainability attractive in our highly Conservative area by showing how inexpensively one can live even in a 4400 SF home that looks like a documented plantation house.
Thank you so much for the information and links.
And yes, all appliances in the house (kitchen and laundry) are EnergyStar. I didn't go nuts on this particular aspect, but picked models that had nice energy performance as well as aesthetic appeal and performance. I could find for you the exact models if you wish.
And finally, I was paid last year by Central Hudson Gas & Electric for my over-production. I made about 1500 kWh more than I produced, and CHGE wrote me a check for $85. It won't pay for my kids' college educations, but it's better than nothing. I'd actually like to see the U.S. go towards feed-in tariffs (where utilities have to pay you more than normal rates for excess energy produced at home) to properly incentivize efforts like mine.