Last November I was approached by legendary energy guru Dadla Ponizil, asking if I would be interested in helping him form a San Diego Chapter of the Passive House Alliance. Little did I know that at the second meeting of the Chapter on March 14th I would end up becoming its first President.
Passive House is a set of design principles and a quantifiable performance standard applied to any building project, producing radically less energy needs, unparalleled comfort and supreme air quality.
Prior to Dadla’s request of me, my own knowledge of the Passive House Standard was fairly rudimentary. Once I accepted his invitation, I started learning more about the Standard and began thinking, “Hmmm, I wonder how easy it would be for LEED Projects in San Diego, already striving for energy efficiency, to also achieve Passive House?” My thought was that because we have such a mild climate that we would not have to do much more to buildings, thus potentially we might be able to dramatically reduce investment in expensive HVAC systems with a small increase in investment in other systems (such as the thermal and air barriers.)
In January the Passive House Alliance US released new regional climate data for the entire country. Our sole Certified Passive House Consultant in San Diego, Lucas Morton, took this new data for San Diego and performed a pro-bono feasibility study on a 5600 sq.ft. LEED for Homes project in Del Mar. The incredible outcome of his study indicates that for the most part we don’t have to go much beyond code construction from an insulation point of view to achieve the Passive House standard.
Why is this incredible news? In this particular project the specification is hydronic floor heating with a backup system for cooling (mini-splits or forced air.) In a home of this size, it is conceivable that this system could cost close to $100,000. If we were able to go Passive House on this project, we might only need a single small mini-split system or a small conditioning system intrinsic to the Heat Recovery Ventilation system (an HRV system is already specified for the home.) By spending, say, less than $10,000 to incorporate air sealing and insulation to Passivhaus standards, we can actually eliminate the things that cause discomfort in house—namely drafts and poor quality insulation installation. A hydronic floor is a great system, and works especially well in poorly insulated and drafty buildings.
So, by utilizing a Passivhaus approach to the building system we might be able to save the project about $90,000 AND achieve the same level of comfort (if not even better!). The home should also cost less to heat and cool and have greater indoor air quality.
The single greatest impact our houses have on the environment is the consumption of energy for mostly heating and cooling of the home—and that includes climates like San Diego. So, the most important thing we can do to make our homes green is eliminate the energy consumption for heating and cooling while maintaining a comfortable interior environment.
The final words are from Luke: "With standard construction it’s kinda like this: You’ve got a bucket of heat (your home or other building) with a big hole in it and you gotta make the HVAC system big enough to keep up with the all the heat leaking through the hole. As long as the bucket stays full, then everyone’s happy and someone pays the bill for keeping the faucet running all that time at the end of the month. Well, we’ve now decided to pay less for our buildings and at the same time plug the hole. The question I just can’t answer is—why would you ever buy an expensive bucket with a hole in it?"
For more information on the Passive House Alliance, visit www.PHAlliance.com
Rich Williams is the president of ArtHaus, a Residential Development company that constructs/remodels and provides consulting on LEED for Homes projects in San Diego County. He is a California Licensed General Contractor, a California Real Estate Licensee, LEED AP BD+C, LEED AP Homes, Building Performance Institute Building Analyst, and is a USGBC REGREEN Trained Professional. Rich has been a member of the SDGBC Residential Committee since 2009, and was recently elected the first president of the new Passive House Alliance San Diego Chapter.
Luke Morton has been working in and around the green building world ever since he quit backpacking around the globe in 2004. He knocked around between jobs as a single-family home rater and a big-picture policy wonk and ended up back in his native San Diego to liberate that housing market from the burden of artificial space conditioning systems. He's keeping his day-job, however, as a building scientist-in-residence at Fergus Garber Young Architects and Pete Moffat Construction. Bona Fides: LEED-AP, GreenPoint Rater, Certified Passivhaus Consultant, CEPE Residential.