Building a Net-Zero House Holistically
- Apr 17
- 7 min read
Guest Blog By Elizabeth Marks
After 20 years of renting and some extensive testing question, I decided to build a house. After searching for a year, I found 10 acres (5 acres of pasture and 5 acres of wooded wetlands) on a dirt road only 15 miles from my office in bucolic upstate New York. The location was idyllic: rolling hills with pastures and woods crisscrossed by horse trails nestled in a friendly and tight knit rural community. I set about to design and build my dream home.
Setting the Project Goal
My first step was to create a holistic goal and resource inventory for my house building process (a holistic goal for this project). Some may say that my personal holistic goal should have been general enough to use, especially since my decision maker (me) didn’t change. However I wanted it to be more specific and identify resources and values that pertained to the building process as well as the place I visualized living in. Here’s what emerged from that process
Core Values:
A living space that is open, light, warm and bright yet energy efficient
Wise use of space – no unused places in the house
Spend money once!
Plan a house that fits my needs now and in the future while considering resale
Stay within my budget
What I need to have in place to achieve those values:
Time to think and plan (don’t feel rushed)
Choose components of the house that I truly love.
Work with people I like and trust; use people who come recommended.
Utilize a budget tracking system
Future Vision:
A place I am excited to come home to; my road is one that I feel good driving down.
A house that visually looks in place with the surrounding farmhouses and country homes.
A house that is low maintenance and allows me to spend time on things I love
Total energy bill < $50 a month
Creating a Resource Inventory
Next, I developed a resource inventory and identified weak links and challenges. Resources included an open, south facing site, friends in the contracting business, and the New York State Energy Research and Development Authority (NYSERDA). In NY, NYSERDA offers rebates and resources to help with green building. They have an energy star program that provides funding for a Home Energy Rating System (HERS) rater, a person who can advise you on green building, what components will give you the biggest bang for the buck, and do a blower door test so leaks can be detected and fixed. NYSERDA also provide funds to off-set solar and green building costs. Challenges included possibly shallow to bed rock soils, lack of building experience, and limited funds while having expensive taste. I did not use the testing questions formally because once I had the context of my project holistic goal, my choices were always clear whether they would move me toward or away from that goal.
For re-sale and financing purposes I wanted to use traditional building materials. Plus I didn’t have the construction experience (or access to people who did) for alternative building materials such as strawbale construction. I explored buying a factory built modular home but ended up not doing it because of cost and it wouldn’t have allowed me to incorporate all of the green building and customized options I wanted. Instead, I decided to go stick built and to be my own general contractor. Even though I had never done anything like this before, I knew what I wanted and I figured no one was more motivated then me to get it done right. Plus I needed to save a lot of money.
The House as a Whole
Because I had great southern exposure, solar was a better option than wind energy (my site was too sheltered by trees and nearby hills) or geo-thermal (excavation costs may be too high). I sited the house so that the long side of one half of the roof was facing due south to provide the most surface area for the solar. When designing the rooms, I placed the majority of my windows on the south side (12 large windows on the south versus 4 smaller ones on the north side). I loaded up the south facing roof with 33 solar electric panels and 2 solar hot water panels on a 1st floor bump-out roof.
Utilizing Allan Savory’s idea that the best way to improved management is through improved decision making, I spent a lot of time thinking and planning. There are a number of things you can do that do not cost extra and are a matter of making good choices. I used advanced framing techniques such as: “California Corners” – 2 studs (vs. 3 or 4) which minimizes pockets of uninsulated areas and uses less wood, 24” on center (vs. 16”) studs to reduce thermal bridging, and 2 x 6 construction (vs. 2 x 4”) – more space for insulation.
Besides the holistic goal and resource inventory, the biggest Holistic Management principle I incorporated was designing the energy system as an interconnected whole rather than individual parts. As is common in farming, people will get fixated on one piece of technology and claim it to be the “best.” When choosing green building elements, it is more important to pick what is best for your site and what works in conjunction with the other components of your system.
With all of the techniques I used, I heard warnings of how “they don’t work.” For example, I went to great lengths to seal all gaps in the sheathing and around windows and used spray foam to create a warm, insulated building envelope. So many times I heard this was a bad practice because a “house needs to breath”. Fresh air exchange is very important, but rather than random gaps in the walls, I opted for an energy recovery ventilator. For about $2,500 this is a system that sucks in fresh air, runs it through a closed system of baffles adjacent to the outgoing stale air which warms it before discharging it through the vents into the house. This is an energy efficient way to bring in fresh, filtered air that I can control.
The basement was constructed out of insulated concrete forms (ICFs). These look like giant Legos with a piece of foam on the outside, a piece on the inside and a 6” gap in the middle in which to place the concrete. They create a cool, dry basement that stays a consistent 55-65 degrees year round. This was one of the green building techniques that was actually cheaper than a traditional poured concrete basement because I used less concrete and I was able to do the labor myself along with a couple of gal pals.
With a well-insulated interior, I could install an energy efficient air source heat pump. This is a system that utilizes electricity to extract heat from the air and distribute it through forced air ducts. It also is an air conditioner in the summer. A lot of folks warned me away from air source heat pumps saying they don’t work in colder climates (I live in Zone 4b). This technology has been around for years and in the last four or five have gained efficiency in colder temperatures. In February, temperatures dipped down to 25 degrees below zero Fahrenheit. While the oil furnace couldn’t heat the house fast enough in my mom’s house (the thermostat was set to 70 but the house was only heating to 64) and she had pipes freeze, my system had no trouble keeping up and every part of my house was warm. Although we had an unusually mild winter, my heating and cooling costs for January through June have only amounted to $130 (0.05 cents a kWh) with heat set to 65 degrees F.
I installed Energy Star appliances, windows and doors. All of my lights are LED which use 90% less energy than incandescent bulbs. I’m forever forgetting to turn off the lights in the closets and those have occupancy sensors in them so lights will go out if no movement is detected. Outside lights also operate on motion detectors.
I searched for ways to reduce/reuse/recycle. During the construction process I generated about 2 garbage bags a week. I used long lasting, low maintenance materials such as Hardie board siding and a metal roof. I opted for spending a bit more on quality, American made materials rather than buying something cheap now with the idea of replacing it in the future. Much to my disappointment, I wasn’t able to use salvaged materials. In the end they cost more either in actual price or in labor. What I was able to do was get fine antique furniture at the local auction. For $100 - $300, I was able to pick up bureaus, writing desks, tables, and oriental rugs, etc. for a quarter of what a similar item would be at Pottery Barn. I used local materials where possible. Floors and other wood were local pine or other wood native to northeast. Using local stone and wood was an important design element of the house. The house was designed to look like an 1840 Greek revival farmhouse, one of many in my area.
The benefits of building green have been immense and hit evenly on my financial, environmental, and social values. My utility bill (heat, hot water, electric) averages $25 a month ($16 monthly utility service fee and $9 on average for propane for a cook range and fireplace), or about $300 a year. Many houses of similar size in my area of upstate NY (think cold winters) pay $3,000 - $5,000 a year for heat and electric. The total additional costs for the energy efficiency components minus my federal and state tax deductions and an incentive payment from NYSERDA was $16,000. I estimate that the payback period is about 5-6 years. My solar panels have a 30 year life expectancy.
Environmentally I am not using oil and have significantly reduced my carbon emissions. Due to improved water efficient appliances and fixtures, I use an average of 40 gallons of water a day, versus 80-100 gallons per day for the average American.
Equally important has been the satisfaction of living according to my values. Building a net-zero home has generated so much positive energy and people are excited to see my home. Good planning in combination with actions in alignment of your values is a powerful force.
Elizabeth Marks is a Holistic Management Certified Educator in New York who can be reached at: Elizabeth_marks@hotmail.com or 518/567-9476
