One of the key goals of this project was to reach embedded carbon neutrality. While many projects claim carbon neutrality of the operation of the building by being energy free or independent of purchasing energy produced from fossil fuels, this house accounts for the embodied carbon footprint of the components of the home, the carbon footprints of the subcontractors who built the home, and the embodied carbon footprint of the materials used in its construction. It has been the intent of the Hamptons Green Alliance to deliver to the owners a true carbon neutral home through the purchasing of carbon offsets from the Chicago Climate Exchange equal to the embodied carbon footprint.
The four-bedroom house in Southampton has been renovated using both cutting-edge, green building technologies as well as proven energy-efficient techniques including: open and closed cell insulation, geothermal heating and cooling, evacuated tube solar thermal hot water, thin-film photovoltaic solar power, conventional solar power panels, rainwater harvesting, LED lighting, and smart home technology. Thanks to this combination of renewable energies and energy saving devices, it is estimated that $250,000 of energy could be saved over a 30-year period.
Interview date: July, 2010
Interviewer: Toby Price
Thanks for giving us the opportunity to talk to you about the “HGA House”. Firstly, how did this project come about? Was it the owners’ idea or the HGA’s?
FD -After one of the members of HGA suggested we look for a project to apply our knowledge; Telemark sent out an email blast to the members of the local chapter of the American Institute of Architects (AIA Peconic). HGA offered to do a gut renovation of the home at cost in return for the ability to treat the renovation as a science project and educate the public about sustainable building.
One of AIA Peconic’s members responded and mentioned he had a client and friend that might be interested in rebuilding his house using renewable energy and sustainable technologies. We met with the architects and the owner the following weekend and agreed in concept to move forward.
Did the project go according to plan? Were any particular challenges faced that would not have existed had it been a conventional house?
BM - We had many challenges. We had three major goals for the project, being Net Zero Energy, being embodied Carbon neutral and achieving a LEED Platinum rating. These three goals impacted most major decisions that were made. For example, had the project called for a conventionally-built home, we would have decided to raise the house rather than make the more environmentally responsible decision to save as much of the existing structure as possible.
We spent a great deal of time planning and used a process called Integrated Project Delivery. This process helped identify the problems before they occurred and allowed all the stakeholders (architect, owner, subcontractors, and general contractor) to work together from the planning standpoint to engineer solutions that would work in the field.
Is there anything the HGA would have done differently based on this experience?
BM - There were many decisions that were made by compromise. One of the more interesting ones was the decision to use thin-film photovoltaics for the available south facing roof. Some on the IPD team favored traditional panels while the architect wanted thin-film. One decision meant we could create more energy, while the other choice was a decision based upon aesthetics.
Certainly when undertaking a highly technical project and using some subsystems for the first time, one learns a great deal. I am sure the next time we use the technologies we did for this project; we will be able to do so more easily.
As we used a number of new technologies, we probably underestimated some of our costs from a time perspective. In the end, we learned a great deal from this experience.
How compatible are luxury and sustainability in the housing sector?
BM - They coexist very easily. Luxury building should demand that the best that building science has to offer is used. There is too much of a mystique that is being built around “green” or “sustainable” building by the media. Though there are some different mechanical subsystems and materials used in green building, the building science has remained the same.
We have been using some of the technologies that are considered sustainable for many years. For example we have been using geo-thermal HVAC systems for upwards of twenty years. In fact, we traditionally installed them in some of the more luxurious homes that we have built over the years.
What percentage of the dwelling’s energy demand is met by each type of renewable energy system, and how and why were the different energy generation and efficiency systems chosen?
BM - We took on this project to answer this very question. We plan on following the costs and energy made by each of the subsystems we used. The owner has pledged to work with us over the next year so we can create a spreadsheet that is accurate, factual, and backed up by data.
To provide solid numbers to answer your question, we plan on tracking the performance of the home over the next year. When completed, we plan on publishing the results on the HGA website.
At this point we conservatively estimate that over the next 30 years, the owner’s saving will exceed $250,000.
It is also important that we not only focus on the energy that we are making via solar and solar thermal technology but the energy that we do not have to make. By using open and closed cell insulation, we are dramatically reducing our need to produce heating and cooling. By using LED lighting, we were able to reduce the total electric usage of the house by between 17% and 21%.
It seems that everyone values the creation of new energy via sustainable measures while I think our calculations may show the measures we took to reduce energy consumption may be equally if not more important.
Remember the phrase, “a penny saved is a penny earned”.
Smart home technologies are still in their infancy. Why did you choose to install such a system and how effective is it at managing the energy balance and expenditure in the HGA House?
BM - Smart home technology is an important component of creating a net zero energy home. Though the system has many functions which I will call customer features, it also monitors energy usage and can adjust the heating, AC and electric usage depending upon whether someone is in the house. Since we are very concerned about energy production and usage, control is very important as it helps us meet our zero energy and LEED goals.
We also installed a system that monitors the energy produced by our solar panels. This has proven to be a fun device as the homeowners are able to monitor energy production and the dollar value of the energy produced in real time.
Based on your experience building the HGA House, is this the start of a lot more Net Zero Home projects to come for the HGA?
BM - I think a better way to say this is, most if not all new projects will include some measure of sustainable design. As I mentioned before, the projects we do demand and we provide the best that building science has to offer.
I can say that for all projects we have been involved with recently, all of them have included a discussion of the various measures that can be taken to reduce energy usage and or create energy in a sustainable way.
There is an educational process that is ongoing where owners, architects, and builders are beginning to understand and learn about the importance of sustainability.
How big could the Net Zero Home market be over the next decade?
BM - I believe we are at the beginning of a paradigm change and ten years from now, what we are doing currently to push technology, will minimally be the standard.
Many towns [in the US] are demanding Energy Star, USGBC LEED, or NHAB Green Building as part of their building code. I see a great and wonderful future and believe the there are many technologies that will be in use then, that have not yet been invented.
One of the key goals of the HGA House project was to reach embedded carbon neutrality (i.e. the house accounts for the embodied carbon footprint of the components of the home, the carbon footprints of the subcontractors who built the home as well as the embodied carbon footprint of the materials used by this home). How easy was it to accurately calculate and, more importantly, certify these carbon footprints?
FD - We have a partnership with Verus Carbon Neutral from Atlanta Georgia to do the carbon audits of the operations of the subcontractors. Verus is one of the leaders in our country for auditing businesses and they have a seat on the Chicago Climate Exchange (CCX). Everyone purchased carbon offsets through Verus. The carbon offsets are certified by the CCX so the entire system maintains integrity.
All founding members of the HGA made a commitment to walk the talk by having Verus perform a carbon audit of operations for a full year and then offsetting their entire carbon footprint and becoming certified carbon neutral. A carbon neutral contractor and subcontractor have zero impact on the project when it comes to calculating the embodied carbon footprint of the components of the home. That made it very easy, since the founding members of the HGA represents the major contractor and subcontractor components. Not only did it make it easier to calculate the embodied carbon footprint but going carbon neutral established us as leaders in our respected industries.
Finally, carbon credits were purchased from the Chicago Climate Exchange to offset this embodied carbon footprint. Ideally, the objective of any future Net Zero Home has to be to reduce the embodied footprint as much as possible, thereby avoiding the need for carbon offsetting (which doesn’t necessarily reduce emissions merely redistributes them). How small do you envisage the carbon footprints mentioned in the previous question could get and how will such reductions be achieved?
FD - In any carbon reduction scheme, we first must mitigate our carbon footprint. What we can’t mitigate we offset. We must always keep that in perspective.
Transitioning to a low carbon society we must start by raising the consciousness level of people by creating an awareness of our own carbon emissions. I believe we started that with everyone involved with this project. It was very important for us to achieve net zero energy since a large majority of a carbon footprint associated with a building is the operation over the life time of that building. We cannot achieve a zero carbon footprint so some portion will always require offsetting.
As the cost of carbon credits and the cost of energy increases good businessmen will continually seek ways to mitigate their own emissions since it affects the bottom line. Implementing an embodied carbon footprint component into existing third party certification systems such as LEED and National Green Building Standard will create a competitive advantage for contractors and subcontractor to become carbon neutral.
If ICEMAN is implemented theoretically every component, product, contractor and subcontractor can become carbon neutral. If that occurred, then no component, product, contractor or subcontractor will have an impact on the embodied carbon footprint of the home, leaving direct energy used in construction, waste and perhaps transportation to the jobsite that will need to be offset.
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