Thermal imaging (used under GFDL)

Passive House design takes into consideration the 3 ways that heat travels – Convection (via a gas or fluid), Conduction (via direct contact of molecules), or Radiation (temperature equalization of surfaces via radiant energy).   In this thermal image of 2 buildings, the red and yellow areas show the least thermal resistance, the green and blue areas show more thermal resistance.  It is easy to see that the building on the left is losing more heat through the walls and windows than the Passive House building on the right. In this article we will focus on heat loss through conduction via thermal bridges, what that is, and what can be done to control it.

My favorite construction management instructor would be quick to correct me if I said anything about pouring concrete.  Today on Dan’s project they placed concrete and tonight I will pour scotch just to make sure I understand the lesson correctly. <grin> I did offer to be Dan’s worst laborer ever and after a very careful second or two of consideration he wisely declined my offer.  As the activity picked up on the jobsite I retreated to my mobile job shack (aka the back of my minivan) where I could observe the hustle and bustle but not get in the way of the muscle.

The folks from Cornerstone Construction came out to start the dirt work and dug one fine hole – complete with an extra deep portion under the front of the house where the Geotech Engineer determined that extra structural fill was going to be necessary.  Unfortunately the original assessment of 2 – 2.5 feet ended up being 4.5 feet.   Dan was able to re-direct some of the excavated topsoil (sandy & some clay) to someone on Craigslist.  The remaining clay soil was hauled away.

On Friday January 9th, 2010 ground was broken for the first home attempting Passive House certification in Seattle. Dan Whitmore of Blackbird Builders, llc, a recently certified Passive House consultant, is building the house and was very excited to finally be breaking ground after weeks of delay in permitting. He was able to get his design that includes a fully insulated slab AND footing set on rigid foam insulation approved by the city of Seattle. This was a key step towards the project being able to meet the energy requirements of a Passive House by eliminating thermal bridging between the foundation and ground.  Here are the details about the house as Dan describes it:

Passive House construction has come to the Pacific Northwest. It is a very energy-efficient and environmentally conscious building method that has been in use in Europe with more than 15,000 buildings built or retrofit to its standards over the last decade.  A few Passive houses have been built in the United States, with some projects already started in Oregon, but a project in Seattle has just broken ground on what is hoped to be the first certified project here.

If I asked you whether a building’s Indoor Air Quality (IAQ) was important to you, I would most likely get a resounding “Yes!” answer. But what if I asked you about that same building’s Indoor Environmental Quality (IEQ), would the answer be more of a hesitant “yes?” It’s easy to toss around TLA’s (three letter acronyms) when discussing building health and comfort, but if everyone isn’t on the same page someone could get lost.

“What on earth is that?” you may ask.   Quite simply it is the measurable energy that was required to create something.  To make a brick, the clay had to be dug out of the ground, transported to the brick factory, added to other ingredients (that also had to be gathered and transported), mixed together, fired in a kiln, loaded on a pallet, shipped to a project to be installed by a mason.  The final measure of embodied energy is the cost of demolishing or deconstructing an item for disposal.  All of those steps take energy and each of those steps also come at an environmental cost such as air and water pollution through creation and transportation.