Last week a group from Oregon Institute of Technology in Klamath Falls toured Desert Rain with Tom. Tom’s tours are chock full of information about the project, the house, materials, the process, and the Living Building Challenge. For those of you that have not yet visited Desert Rain, you are invited to come along here for a condensed version focusing on the Seven Petals of the Living Building Challenge.
“About 6 years ago we started thinking about building a home here in Bend. We wanted to build a green home. Well into the design we were driving in Utah to go backpacking and we were listening to the radio and heard a presentation of a Bioneers conference by Jason McLennan, the founder of the LBC. We both just knew, right there – that’s what we wanted. We realized we were really drawn to the LBC for a number of reasons. One, it is about a living building. It is not about getting points and putting a plaque on the wall. It is very much a performance based standard. We really wanted our home to perform that way, not just to look nice and have green products in it. We were excited about that aspect of it and the community aspect of it, and the equity aspect. All the various pieces of the Living Building Challenge excited us and challenged us. “
The Living Building Challenge is based on Seven Petals. Tom talked with the group about each of the petals.
“The Site petal is very much focused on limiting growth and building on existing land or renovating in place, rather than expanding and contributing to urban sprawl. Site issues revolve around accessibility and minimizing the use of the automobile. We particularly picked this site because it is in a diverse neighborhood, very easy access to everything – library, stores, and recreation. We like to bicycle and walk so it is very easy here. It is also a place we thought we could age in place. The other piece is a living building fits into the community. There’s a certain sense of engagement that invites participation in the neighborhood and not just isolating ourselves. That was something that really attracted us about the Living Building Challenge – the site piece of it. “
“The Water Petal has two components. The first is net zero water in terms of where the water comes from. We won’t use any city water. All of our water will be from the water that falls on the site, the rainfall. We have a very extensive rain water collecting/harvesting system. All the roofs that you see on all the five different structures here – all that water feeds into a single cistern – a 35,000 gallon cistern. We get to charge that cistern once to start. So net zero water in terms of source and also, what they call ecological water flow. That is, all the water that falls on the site needs to remain on the site. Storm water needs to remain on the site. After it has run thru the house, the discharged water has to remain on the site. Nothing will go in the sewer. Water has actually been our largest challenge here because we’re in the city limits. If we were in the country we could put in a septic system for wastewater and the problem is solved.”
“The other side of the ecological water course is handling our wastewater. The original intention was to build an underground bio-constructed wetland that would handle both the greywater and the blackwater. Current regulations won’t allow us to that. We’re still going to build one. The only thing that will run through our constructed wetland is greywater. The greywater will travel from the various buildings into a collection tank that basically separates any solids. From there it goes into a small constructed wetland where it is processed using a natural process through gravel and plant root systems. At that point the DEQ qualifies it as Type ll greywater. It will go to a holding tank by the side of the garage and can be used for irrigation and water features. Basically it will be used as irrigation water or evaporated. It will be sub-surface irrigation. We are relying on the constructed wetland to purify the water.
Then we have the blackwater. That’s been particularly challenging. Early on we had some indication from the city that they were going to allow us to use the constructed wetland for that purpose. So we designed the home that way. We didn’t design the home based on the idea of having a composting toilet. So we had to go to plan B and C as we worked our way through that issue. What we’ve come up with is a using a hybrid system. The sewage will go from the homes to what we’re calling, ‘The Desert Throne’. It will be a separate building. Solids will go through a commercial scale composting unit and the liquids will go to what we are fondly calling, the ‘evapatron ‘. Basically it is a large scale evaporator system. That is a dead end. Once it gets there it will be composted or it will be evaporated. That takes care of the blackwater and everything stays on site. We are required by code to be connected to city water and sewer for safety purposes.”
“Then we move to the Energy part of it. The imperative there is net zero energy. We want to be not only net zero in the home, but we also wanted to provide enough energy for two electric vehicles so that our transportation is also net zero energy. Our first approach was to have as efficient building envelope as possible. Our intention is to be net zero energy or maybe overall, surplus energy producing. We’d like to be a power plant too and provide enough energy to be on the positive side. I think it’s likely. We’ll be grid connected so we’ll be net metering with the power company. We’ll use the grid as our storage device for now. The house will be heated, in fact is currently being heated, with a solar, atmospheric hot water system with infloor radiant heat. When I say atmospheric, it is not pressurized. When there is no demand all of the water drains back to the storage tanks in the corner of the house so there is no risk of freezing. There is also a super efficient therma-monoblock heat pump that is tied into that system if there is not enough solar heat and we need a little boost.” Jim Fagan, General Contractor with Timberline entered the conversation, “ It is an extremely efficient, electric, air to water heat pump. Also the domestic hot water is tied into the system.” An interesting side note: Bobcat and Sun the contractor that installed the solar thermal system said that normally on a home here in Bend, based on efficiency of the building envelope, at least 26% of the homes’ energy could be met with the solar system. The calculations on Desert Rain are somewhere in the 86 to 90% range that will be met by solar.
Then there is the Materials Petal : The red list is very stringent. There are 14 chemicals or materials that are not allowed. “That’s probably been our second biggest hurdle – just vetting through materials. We have a very comprehensive process. We maintain a spreadsheet with all these questions that would have to be answered for that material. We’ve had to reject a lot of materials for various reasons. PVC is on the Red List. It is very difficult to build a home without PVC. There are a couple of instances where we’ve had to get a minor exemption because there is just nothing but PVC – like some of the wiring in the house has a PVC coating. Jim Fagan comments, “there is really no other code material we can get. Another one is that there is a fire retardant in this foam that is on the red list but there is no alternative.” In order to mitigate that, we found that if you only put on 4” at a time it off gasses very thoroughly. Where as, if you put on 8” at one time it sort of traps the gas and it takes years to off gas.
We’ve tried to stay with local materials as much as possible. Part of the materials requirement is that heavier items come within 350 miles. That would be stone, cement products, aggregates – the heavy materials. Then you can step out as the weight range shifts, you can go within 500 mile. As you get a little lighter you can go 1000miles. It is basically intended to minimize the carbon footprint. There is so much CF associated with the transportation of materials and that is always externalized. Basically, society pays for it rather than the person actually using the material. The LBC feels that needs to change. We need to pay the current dollars for those things or minimize them.”
Jim adds, “One of the things that is required when we do get an exception, like the PVC on the wire or the fire retardant; the LBC requires us to write a letter to the manufacturer. We let them know that yes, we are using this because it is the only thing that will make our envelope what it is. But we tell them we’re not happy about it and we want them to figure out a different way to do it. It is pretty comprehensive -covering all those bases. Our stucco contractor has developed his own Oregon mix. Most of those products, at least part of them come from California or Mexico. He found all the aggregates and parts and pieces to create a stucco product that is all Oregon. That is kind of cool.” That is part of the Living Building Challenge intention, to be pro -active that way and push change, not just exemplify it but push the envelope with manufacturers and sub -contractors.
“There’s lots of interesting stories about materials. Every material that has gone in the house has a story. Interestingly we know the story a lot more than on a normal house because of this process and the qualifications of that material. We’ll see that even more as we get into the finish work. One example of that is there is a fair amount of walnut on some of the surfaces, counters and built-ins. All the walnut in this house comes from one tree that was harvested when a parking lot was being constructed in Portland at Concordia College. We got that whole tree. Everything has a story and that’s awesome. For me it adds a lot of interest and connectivity to the house. When we look at that walnut – the rest of our lives we’ll feel a special connection with that walnut knowing where it came from or where the tile came from or the story with the rocks or whatever. I think that is an attribute of the Living Building Challenge.”
“Health is the next petal. Having a civilized environment basically means, light and fresh air. And what is calld biophilia, basically mimicking nature in some way. It is pretty well documented that humans respond to natural settings and natural dimensions. We wanted to build a supertight container and have controlled air through an air exchange. We’ll be required to measure air quality after the house is constructed, for VOCs and particulates. We’ll have to measure it again, nine months later to demonstrate that the house has exceptional air quality.”
Jim tells, ‘We did a preliminary blower door test. We were at .65 air changes per hour. That is almost at the Passive House standards. We did that pre -sheetrock and actually don’t even have the spray foam in the sub- floor or under floor yet so we’re pretty happy with that.”
“Then we move to the Equity part – that is making things human scale and accessible. All of our homes are wheel chair accessible. We did that for a few reasons. One, we already have a couple of friends in wheelchairs and we know as part of the aging process people are in wheelchairs. Also equity refers to terms of production of materials. All the lumber in the house is either reclaimed or Forest Stewardship Certified. They certify all the way back to source, and that the labor was treated properly, and the material is treated properly. Awareness and that consciousness – we need to embody more and more. I think a lot of times we feel like we don’t have any individual power. But certainly we make a choice. I think collectively we have an enormous amount of power to make important choices and that really applies in this materials and manufacturing.
Finally Beauty. We hope we’ve designed something beautiful. Beauty is in the eye of the beholder. We’re confident that the space and form, and when the terraces are in and the landscaping, the courtyard, the interior finishes – it will be a beautiful home. Certainly it will be beautiful in our eyes.”
This dialogue is a glimpse of the information to be gleaned from a tour. Tom and Barb very much see Desert Rain as a demonstration project and an educational tool. Tours are part of that process. Many groups have been through the site at various stages of the building process. Are you interested in learning more about Desert Rain? Send us an e-mail or email@example.com or subscribe to our e-mail newsletter at the bottom of this blog page.