The Natural Building Intensive (NBI) brings together a collaborative group of experienced and enthusiastic instructors with students in an in-depth, hands-on experience in natural building, from the design and planning stages through the finishing touches. Over the course of a 12-week curriculum, students in the Summer 2010 program are helping to design and build a complete home from start to finish – a building handcrafted from natural stone, straw, timber, and clay along with more modern building materials, emphasizing an integrated approach to natural building systems for a northern climate.
This year’s clients, Bryan Redmond and Kate Clemente, live in Montpelier, Vermont and for years have dreamt of building their own home. Three years ago they purchased a piece of land on a hilltop in Middlesex abutting the Green Mountain National Forest. They cleared trees, put in a driveway, and started to think about the design of their future home. Bryan enrolled in Yestermorrow’s 6-day Timberframing course in 2007 and met instructors Josh Jackson and Skip Dewhirst. After finishing the course he was convinced he wanted to build a timberframe home, and started to work with Josh and an architect friend to develop a design concept.
Bryan and Kate were starting to think about the process of building their home last summer when they went to hear Ace McArleton, natural builder and Yestermorrow instructor, give a presentation. Having initially dismissed the idea of building a strawbale home, they were intrigued by the images and past projects Ace showed in his slideshow. After further conversation the topic of the Natural Building Intensive came up. Having taken a course at Yestermorrow, Bryan was familiar with the School, and realized that many of the builders he talked to were also instructors at Yestermorrow and taught in the NBI program.
After meeting with a variety of potential clients last summer, Yestermorrow staff selected Bryan and Kate as the clients for the 2010 NBI program and hired José Galarza as the NBI Program Director and Designer. Throughout the winter José worked with Bryan and Kate to refine their design ideas and put them onto paper and into digital 3-D models. He also worked closely with the different instructors in the program to coordinate the curriculum components and determine what elements the students would build. Due to the scope of the project (a 1700 square foot home) they determined early on that it was not be possible for the students to complete all aspects of the building in 12 weeks, and it would be necessary to collaborate with additional contractors to complete other aspects of the project. The client Bryan Redmond took on the role of general contractor, hiring the crew of New Frameworks (http://newframeworks.com) for the main components of natural building during the NBI program. The partners of New Frameworks are Ace McArleton and Jacob Deva Racusin, both experienced Yestermorrow faculty members (Jacob was the former NBI Program Director in 2008 and 2009). Their crew includes a variety of Yestermorrow instructors as well as alumni.
On May 30th the eleven students in the program arrived on campus to kick off their 12 weeks with a 5-day introduction to natural building, then a 3-day survey of Permaculture and site design. Next they went out in the woods for 2 days of Stump to Sticker, looking at forest management, harvesting and milling. The class worked on site in Middlesex to fell trees and cut them in a portable bandsaw mill for use in the structure. Next they came back to campus for 6 days of Timberframing, culminating in a raising day on June 19th.
From then on, the students were on site every day, learning basic carpentry skills while installing the roof and interior walls, laying the strawbale walls, and applying natural plasters to the bales. The program concludes with work on stone masonry, super-insulation with cellulose, electrical and plumbing rough-ins, and many finishing touches in the final week leading up to graduation and an open house on August 20th.
At the end of the program, the clients will still have lots of work to do to finish the interior of their new home, but the majority of the building envelope will be complete. The design of the home includes many unique features which demonstrate a strong commitment to sustainability, high energy performance, craftsmanship and beauty. In addition, the house will achieve an Energy Star rating through Efficiency Vermont’s Energy Star Homes program, and the clients hope to engage in long-term monitoring of moisture content, indoor air quality, and energy performance so that the project can serve as a demonstration of high performance natural building systems.
The home is designed with a southern orientation to take advantage of passive solar heating. A large percentage of the wood in the structure was harvested on the building site and from local sawmills. The foundation is constructed of insulated concrete forms made Durisol, a product made of recycled concrete and wood chips. The roof is constructed with 16.75” of cellulose insulation (made of recycled newspapers) for an estimated R-value of 60 (assuming R3.6 per 1”). The walls are strawbale infill around a timber frame, with unique knee braces framed to the interior for ease of plastering. The strawbale wall envelope is finished with a coat of lime-stabilized clay and manure plaster for moisture protection and initial air barrier, followed by a lime-sand-manure top coat for durability as well as vapor permeability. The manure was gathered from neighboring horse farms by the clients, utilizing a local waste product. Interior partition walls are constructed with woodchip clay infill for sound deadening. The standing seam roof is made of recycled steel and the wood floors and trim are made from local, native wood.
The building envelope features exceptional detailing for contiguous air barrier, contiguous thermal barrier, and implemented a comprehensive moisture management strategy throughout design and construction, addressing head-on the issues of moisture management in a vapor-permeable, organic-based wall system. Passive solar heating will be supplemented by a high efficiency Euro style woodstove with a direct vent propane back-up. The mechanical systems include heat recovery ventilation, a necessary component to mechanically control air exchange in a super tight and well insulated structure. The building also features WaterSense certified fixtures and a high efficiency toilet.
One of the key elements of the success of the NBI program is its emphasis on team building. A major focus is on building relationships between the key players involved in this project on a macro scale (instructors, contractors, client and the School) and also within and among the students themselves as a team. The curriculum also emphasizes the individual development of each student to strengthen and support the skills-based learning of the program.