My wife and I embarked on this adventure in 2008 when searching for a home to buy. Our search criteria included a very walkable, safe location close to transit, parks, and restaurants, in a good school district; a strong, durable structure and roof to withstand Miami storms and last for 25 years; an existing pool or enough room to build one; and an open floorplan with living spaces just the right size - not so small as to feel cramped and not so big as to be wasteful. After searching for over a year we began to realize what we wanted was not on the market and perhaps did not even exist.
As an architect I was able to convince my wife that it was best to design and build our home instead of settling for less than what we wanted. Once the search was limited to location it became much easier, and we were very fortunate to find the great location for this project. We have been able to inject our values into the design of the house and form it to the way we prefer to live, as opposed to molding our lives to fit a pre-existing house.
With a design starting from scratch we were afforded the flexibilty to expand greatly from our original home purchase search criteria. The strong, durable structure became a poured-in-place concrete shell. The roof became a sturdy, energy efficient standing seam metal roof with recycled content on the concrete deck. Window and door selection was based on high impact resistance ratings and good thermal performance. The open floorplan flows from the entry, through the library, into the living space with vaulted ceiling and open loft space above. The bedrooms are all on the small side, meant for sleeping only so that activities stay in the communal spaces.
As both of us are committed to sustainability, we started with a minimum concept of what eco-friendly measures we would incorporate into the design. PV and solar thermal panels are a must. We already have a number of energy efficient electronics, so Energy Star appliances just make sense. With particular consideration for our children we have been very careful to select materials and finishes that emit very low or no toxicity. We prefer natural ventilation over air conditioning, so the design incorporates passive air circulation using operable windows and the chimney effect. In trying to conserve water we specified dual-flush toilets, low-flow water fixtures, and a rainwater capture cistern, as well as implemented native landscaping to eliminate the need for a sprinkler system. When asked what the added cost is for this home to reach LEED Platinum standards, I have to answer that it has been simply the LEED registration and certification fees. Most everything else has been something we intended to include anyway. Since we were already at or close to the platinum level, it made sense just to document and submit for the official certification.
Net Zero Electricity Potential:
Judging by the last three years of electric bills at our current rental, our family uses between 8700 and 9400 kWh per year. The solar panel array for our new home is expected to produce more than 7500 kWh per year, leaving a worst-case scenerio of about 1900 kWh difference. That means that if the new home is designed even just 20% more efficient than our current rental, we will be at net zero electricity for the year. The current HERS estimate shows us at 33% more efficient than the HERS baseline home when not considering the PV. Of course these are just projected estimates, and the proof will come once we live in it day to day. But the potential is certainly there for us to produce more electricity than we use, which I find very exciting.