Building my dream home GREEN

At Verdis we are all driven to reduce our impact on the environment; at work and at home. Everyday, we work with clients to develop and implement changes to reduce energy use, reduce waste, recycle more, and simply reduce our collective impact on the natural environment. Beyond working with our clients, all of us individually pursue our passion to make the environment healthier in other ways. Craig chairs the group Mode Shift Omaha working to broaden active transportation options in Omaha, and Daniel serves on the Metro Transit Authority Board. I’ve been working on my personal impact on the environment, and have been building my dream home in the most sustainable manner we could.

House

What were we able to accomplish from a sustainability perspective on our new home?

 

My husband and I are quite proud of our HERS 32 Rating.  A Home Energy Rating System (HERS) rating is a score that compares a home’s energy use to a modeled house that is the same as your house, but built to 2004 International Energy Conservation Code. For a HERS rating, the lower the better. A home that scores zero is a Net Zero home, meaning it produces as much energy as it uses, typically through solar or wind power. Our HERS score of 32 means that our house is 68% more efficient than the HERS reference/modeled home. The U.S. Department of Energy determined that a typical resale home scores 130 on the HERS Index, so we are 98% more efficient than a typical resale home! My understanding is that only a handful of homes in Nebraska receive a HERS score this low on an annual basis, and once we add solar – net zero here we come!

 

Here are the highlights of changes we made from a typical home, which make our home more energy efficient and lessen our environmental impact:

Mechanical Systems

  • Open loop geothermal heat pump uses the 52 degree ground water temperature to heat and cool the home. We don’t need an air conditioner! And we expect our heating & cooling bills to be only $39 a month on average. The cost of this system is significantly supplemented by the Federal Tax credit.
  • Hybrid heat pump water heater uses the energy in our basement’s air to heat our hot water (along with electricity). This water heater is twice as efficient as a regular hot water heater (expecting to cost only $9 a month for hot water heating).
  • A variable frequency drive (VFD) on the well pump allows the pump to use only the energy needed to pump the amount of water needed at the time, instead of only having two options of “on full speed” or “off.”
  • A desuperheater transfers excess heat from the geothermal system to the water heater to preheat the water.
  • An Energy Recovery Ventilator (ERV) acts as the home’s lungs bringing fresh air into the house, while recovering some of the energy in the stale air before its removed from the house 

Construction Methods

  • rigid foam2×6 framing of the walls to allow for two extra inches of insulation (57% more), compared to traditional 2×4 construction
  • One inch rigid foam insulation used continuously on the exterior (instead of plywood) provides additional insulation and air sealing (see image at right)
  • Borate only treated blown in cellulose insulation in wall cavities, mainly used for health reasons, but also because cellulose is a great insulator and made from recycled paper. We used Green Fiber insulation made in Norfolk, NE
  • Energy efficient windows by Gerkin made in Sioux City, NE
  • Some Forest Stewardship Council (FSC) wood during construction, bonus from Millard Lumber – thanks!
  • Caulking the top and the sill plate before insulation to seal air gaps
  • Capillary breaks under and around foundation (plastic under the basement floor and waterproofing spray between the foundation walls and footings) minimizes the water that can enter the basement through the concrete
  • Passive radon mitigation system that allows radon under the home to exit through closed pipe that goes out the roof
  • Rough in for future solar, hopefully installed before the tax credit expirescarpet tile

Lighting, Interior Finish, and Other Sustainable Choices

  • LED lighting, we found screw in bulbs in traditional fixtures were the most economical, especially when bulbs were purchased in Council Bluffs.
  • A detached garage (attached garages often bring unhealthy air into the home)
  • East and south windows to warm the house in the winter, and larger eaves to keep the sun out in the summer
  • Energy Star appliances
  • No and low VOC paints/stains
  • Low flow water faucets, toilets and showers
  • Recycled carpet tile samples in our office / guest room (see image at right)
  • Products made close to home to minimize transportation emissions. For example, pre-finished wood floors are often finished in Asia with significant emissions from that transport; ours is wood floor from the United States and manufactured in the United States.

Implementation Evaluations

  • Blower door tests evaluated air sealing. We did this before paint, trim and floors were installed, to see if the house was sealed well at a point – it was!
  • Personal inspection of the items that were different from what our builder usually used, like the blown in cellulose insulation

So with all of these great energy saving strategies – What can I tell YOU about saving energy at your home?

  1. If you have incandescent lights in your home, go to Home Depot in Council Bluffs ledsTODAY and buy LED light bulbs to replace all the lights in your home. REPLACE them TONIGHT.

If you have a large home, this could add up to a couple hundred dollars investment, but the investment will pay for itself in electricity savings over the course of a year or less if you are replacing incandescent bulbs. The payback if you are replacing compact florescent lights (curly cue ones) is not as good. This Home Depot has the best prices I’ve seen for LEDs; a 60w-equivalent bulb is usually $5-7 each. On sale for $3 a week or two ago… After the first year, you’re saving lots of money in electricity each year! Here is a handy calculator to see this savings.

  1. If you are building or want to do a more significant project in your home, air sealing and insulation are the most cost effective ways to save energy. I would suggest getting your home’s HERS rating calculated. Then I would talk to the rater that does this calculation to see what you could do to improve your specific home in a cost effective way. I used American Energy Advisors (AEA) here in Omaha for this, and was very happy with the work they did for us and the advice they provided throughout the building process.
  1. If you are installing new insulation, take the day off and oversee the installers. The installers my builder used had never installed blown in dry cellulose and were given insulationno instruction on how to do so. When the ‘finished’ insulation was reviewed by the manufacturer representative to ensure it met manufacturer specifications (at my special request), it was short about 25% of the needed material. I’ve heard of other installers in town just skipping entire wall cavities. My advice here is to get lots of references before you choose a company, spend 20 minutes learning what you need to on the internet about how things should be installed, and then be there while the job is happening to actively review the installer’s work.

At the end of the building process, when AEA brought their infrared gun to check wall temperatures on a very cold December day, I was happy with the temperatures on the walls at this point. We’ll see a few years down the road, whether the insulation settles or not, a check we can do with an infrared gun that reads wall temperatures.

  1. If you want to build a green home, make sure you find a builder in the area with some experience with this, and just as importantly, a builder that is interested and willing to learn. Based on my research and conversations with others in the green community, there doesn’t seem to be a go-to green builder in Omaha.

We asked Landmark Performance Homes to build for us, and the owner Steve Faller was great throughout the entire project. Whenever we had a green practice in mind that Landmark had never done before, we talked through it. Steve gave us his insight based upon years of building experience and together we chose the best path forward. This was critical to keep our costs under control and to ensure that best practices in green building were incorporated whenever possible. I found Building Science and Green Building Advisor to be the most helpful websites when sorting out detailed questions on what to do.

  1. If you are buying a new home, check out the HERS scores before you buy. Here is the Residential Energy Services Network’s (RESNET) database of all HERS scores. Also, keep an eye out in realtor descriptions for HERS scores; local builders are working to get HERS scores included as part of the Multiple Listing Service (MLS) system where all realtors share listing information. If you are buying a home with a lower HERS score, this will save you money every month and should tip the scales when selecting between homes.

 

In the end, we love our dream home, and we are proud to have built a home that will stand for hundreds of years, making a small ongoing impact on our environment.

And if you wake up to this view everyday, how can you not want to protect our environment.

 

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