HEATING 45% MORE EFFICIENT THAN TITLE-24, 90% MORE EFFICIENT THAN OLDER HOMES
Title-24 specifies energy usage guidelines for new homes. California has some of the most aggressive rules in the world. For a home of this size, title-24 required heating + hotwater energy usage of 998 therms/year or less (18.66 kBtu/sf-yr). The actual usage has been apx. 11kBtu/sf-yr. The home is very tight with proper air handling + flow plus the furnace is efficient.
ELECTRICITY + MONITORING
The home is equipped with an eMonitor power monitoring system. This system displays power used and provides alerts in the event of out of normal usage power. For example, the coffee bar circuit will send out an email if the espresso machine is left on too long, or the fridge will provide an alert if the door gets left open.
This is a view of the house in standby mode. The AV systems are awaiting commands, all lighting keypads, security keypads, remote controls, network switches, security system, monitoring are on. A desktop is in standby mode, a laptop + 2 cell phones charging, an exercise machine is plugged in, insta-hot heater is plugged in as are all fridges. One printer is plugged in, phone system is active. This is a view of all the latent loads in the home, not just the advanced automation. The control room in standby plus the lighting system on the 2nd floor (a portion of the "Unmonitored Power" above) consume 275 watts - a little less than $50/month at $0.25/kwh.
Electrical usage has been fairly high for the past few years as the lower level has been used as a multi-person office for 3-5 people in the owners business. Additionally, there are 11 computers total onsite and only 2 of them could be considered energy efficient. Total household usage is estimated to be apx. 1300 kw/h month (by circuit level analysis.) If that were billed by PG&E alone, the cost would be apx. $350 and $450/month. The house has not been run this way and no bill reports those #'s however.
Meets LEED Gold Standards*
The home was designed and built to be sustainable and green from the get go.
While the US Green Building Council had not published the LEED standards for homes until late 2005 (and even then, it was just a pilot program), many the guidelines were well known.
*The house has not been formally rated but has been reviewed by technical professionals and improved since original construction. This self rating is a best effort but may contain errors. There is one major deficiency in the house - there is an air handler in the garage. Air handlers should be in conditioned space for efficiency and air quality. We don't feel this has negatively effected our efficiency as our gas bills have been extremely low.
LEED had not published it's standards in 2003 when the design began but all the key personnel involved in the design and construction were on a mission to build a truly green home.
The current standard has an adjustment for larger homes. If the lower level is considered office and excluded from square footage, the home would be just shy of platinum level just by adding flow restrictors to the showers + faucets. A grey water system, which was partially planned for from the beginning, would push it clearly into platinum category. If the lower level is considered part of the home, then the large home negative points would need to be offset by alternative generation - probably a 2.5kw solar system.