Category Archives for Uncategorized

On Our Green Journey, We Discovered Passive House

November 13, 2010

@font-face {
font-family: “Arial”;
}@font-face {
font-family: “Cambria”;
}p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: “Times New Roman”; }a:link, span.MsoHyperlink { color: blue; text-decoration: underline; }a:visited, span.MsoHyperlinkFollowed { color: purple; text-decoration: underline; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0in 0in 0.0001pt 0.5in; font-size: 12pt; font-family: “Times New Roman”; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0in 0in 0.0001pt 0.5in; font-size: 12pt; font-family: “Times New Roman”; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0in 0in 0.0001pt 0.5in; font-size: 12pt; font-family: “Times New Roman”; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0in 0in 0.0001pt 0.5in; font-size: 12pt; font-family: “Times New Roman”; }div.Section1 { page: Section1; }ol { margin-bottom: 0in; }ul { margin-bottom: 0in; }

Last week, we had a chance to meet Dr. Wolfgang Feist in San Francisco, where he gave a free public lecture on Passive House at the California College of Arts.  Dr. Feist is the founder of Passivhaus Institut and is on the faculty of civil engineering at University of Innsbruck.  He was on his way to Portland, Oregon for the 5th North American Passive House Conference.  My post is a quick summary of the notes I took from that talk.  Just as a new student may not get all her facts correct, my notes below reflect my current state of enlightenment and ignorance.  OK?  Here it goes –
The Passive House is not an energy performance standard, but a concept to achieve highest thermal comfort conditions on low total costs.  The passive house buildings don’t have a particular look and or follow specific architecture.  The concept can be applied to different types and styles of buildings.  What we found impressive about passive house is the performance.  By following the passive house concept a building built in 1991 in Kranichstein, Darmstadt, Germany was able to reduce the energy consumption of the building by 80%.  The building performance was monitored from 1991 to 2010.  Amazing, isn’t?
There are 5 principles –
1.    Insulation.  Lots of insulation on the exterior walls, roof and the basement ceiling.  In the particular building shown in the case study there was 12-inches on the roof, 12-inches on the exterior walls and 10-inches on the basement ceiling.
2.    Free from thermal bridges.  Basically you want to eliminate the path that heat can flow.
3.    Air Tightness.  Warm air moving from inside to the outside of the building will deposit moisture into the building as it exits, causing problems for the building.  Air tightness of the building is achieved by applying special tapes and testing it using the blower door test.
4.    Energy gain window.  Triple pane windows allow more solar gain and less energy loss.  Note that the solar gain in the winter in central Europe is 1/5th of what’s in the Bay Area.
5.    Heat recovery ventilator. HRV is a quiet, hygienic and efficient device that provides conditioned fresh air to come into the building, providing comfort and reduced radon exposure.  The standard for HRV, by the way, is different between Europe and US.
Today all European countries have passive house demonstration projects.  Passive house demonstration projects are also found in other countries such as Russia, Japan, China, Korea, South Africa, Australia, Antarctica, Chile, Canada and United States.
To learn more about Passive House please visit Passive House Institute US and also the Passipedia site, where passive house information is available to the public and member postings are reviewed by scientists.  

Search For Land… Got A House

October 21, 2010

One of the criteria for our green, sustainable home was walkability.  This means being able to walk-to or at least bike-to grocery stores, farmers market, coffee shops, restaurants and entertainment.  Another criteria was good southern sun exposure for solar applications and growing a nice edible garden.  The desire for good air quality and low noise level meant staying away from major streets with high traffic.  There were few other items on our “selection filter” like buildable lot and reasonable cost.   Being the analytical couple that we are we had a spreadsheet with weighted scoring with all of our selection criteria with formulas that summarized numerical value for each of the place we considered.  At times sticking to our agreed upon filters was tough.  We felt impatient and just wanted to begin our journey of building our green home.  It took us over 2 years of serious searching to get a place for our green home project.

In 2008 we were looking for an urban infill lot within the city limits of Santa Cruz.  We were thinking of new construction with perhaps ultra modern design.  With the declining real estate market we thought we’d be able to get a plot of land at a good price.  Well, the people who owned such properties apparently were not in any rush and wanted much more money than we offered.  We looked at MLS listings every few days.  We rode our bikes around town to identify unbuilt lots and looked up the owners info at the county tax assessor’s office and sent them letters.  No sale.  The most exciting thing was going through 3 counter offers on 6098 sq.ft. lot that fizzled when we couldn’t agree on price.

In 2009 we expanded our search to include fixer-uppers and tear-down homes.  We were fortunate to be working with Gary, our real estate broker who also is an attorney and builder.  He gave us valuable remodeling insights as we looked at various properties.  In fact, he opened our eyes to the value of renovating an older building when we bid on the 109-years old Victorian house that was ready for gutting. We lost that bid but gained new perspective.

In 2010 we started the year by bidding on a foreclosure house that was in move-in condition.  The house passed our selection criteria and our idea was to “green it” with additional insulation, water efficiency and energy efficiency.  Though we put in a strong offer we didn’t get it.  We learned that even in this down economy when a good property shows up on the market the competition is fierce.  So we lost that bid and continued searching.  Few months later we again lost the bid on another house that was in ready to move in condition.  In retrospect we are so grateful that we did not get any of those because what we got is a gem.

In late July we saw a house come on the market that looked interesting — a 1922 Craftsman style home that had signs of deferred maintenance and good bones.  It wasn’t love at first sight but it fit our criteria and we didn’t find anything horribly wrong with it so we put in a strong bid, fully expecting a counter offer and bidding war.  Then we got the call from Gary that evening saying our offer was accepted.  We were stunned… and happy.  As we learned more about the house, neighborhood and architecture we felt happier and happier.  More on that later.

So we started our green home  journey with the idea of building something new that would be green but instead we will be doing a project that is much greener.  We are reusing the parts of the house that was built 88 years ago, such as framing, foundation, roof, nice woodwork and built-in features.  What could be greener than that?

1 6 7 8