Madoc Performing Arts Centre, August 2008
soma earth ARCHITECT 2008
Madoc Performing Arts Centre
Lowest Embodied Energy – Natural, Straw Bale Building
Madoc, Ontario
The students at Flemming College Sustainable Design Program finally finished their 5 month course building the Madoc Performing Arts Centre with an internal opening ceremony on Aug 21, 2008. Considered as one of the most sustainable buildings in Canada, it is built with the principles of the lowest embodied energy as much as possible. It considers aspects that not even a platinum LEEDS building rates yet. Only the lowest-impact and longest-lasting materials have been chosen to build this structure. From the compacted stone of the rubble trench foundation, to the hempcrete grade beams, up through the load-bearing round straw bale columns, to the hempbale & earthen plaster walls, the living green roof over the front porch and galvanized metal roofing on the rest of the building, this project represents the best available choices for building materials in our northern climate.
Earth Plaster over Strawbale wall
The hempcrete grade beams are being used for the first time ever on this building. Hempcrete is a mixture of chopped hemp, hydrated lime and a small amount of either portland cement or quick-set gysum. A reaction between the lime and the hemp results in a very lightweight material that still has reasonable compressive strength. The advantage of hempcrete over regular cement is that the hempcrete is both structural and insulative, so both ends are achieved in the same pour. It is also lower in embodied energy. The disadvantages are a longer set time (2-4 weeks) and lower strengths. However, where the high ultimate strength of concrete is not necessary, this option works well.
Chordwood wall
The building is based on upon eight load-bearing columns made of large, round, hemp-straw bales. These 4×4 foot round bales are very tightly compacted when they are made, and stacked three high they make for very stable and strong columns. The straight walls sections between the round bales are infilled with regular, rectangular hemp-straw bales. Clay plastered straw bale walls are one of the most environmentally friendly building systems available. The combination of locally-grown, minimally-processed straw and locally harvested clay means that the embodied energy in the wall system is only a tiny fraction of any other wall system. Combined with excellent thermal performance over the lifetime of the building, this system saves energy in every possible way, and is comparable in time and cost to any conventional building system.
Local round wood column raising
We have used three different insulation types for the three 2 x 6 double frame wood stud wings; One wing is infilled with hempcrete, which is a site mixed combination of ground hemp, water and hydrated lime. Another is infilled with light clay/straw. For this material, we blend chopped hemp straw with a small amount of clay slip (a runny mixture of clay and water). The third wall is insulated with cotton batt insulation. These batts are similar to fiberglass or Roxul batts, but are made from non-toxic, recycled denim fabric.
Front Entrance
The building uses available technologies to drastically reduce its resource consumption and waste production; from the geo-thermal heating and cooling system that allows the building to maintain a comfortable temperature year round without relying on fossil fuels, to the PV panels that provide its electrical power, to the solar ventilation system that provides the building with pre-warmed fresh air, to the rainwater collection system that provides flushing water for the toilets.
Rubber tire wood column foundation trenching
Built by the students of Flemming College Sustainable Design Program, the building was well received by the Township of Madoc, Ontario. A decorative element that included participation with the local children, they were invited to make handprints on the front exterior wall, simulating the leaves of a tree. The students finished off the building with some beautiful final touches; a chordwood wall, an earth brick floor & countertop, hand carved wood trim, rope trim edges, rough hewn pineboard decorative features, timber framed beams with hand carved joints, local roundwood columns sanded & bleached, etc. My good friend, Henry Wiersma, supplied the compressed earth adobe bricks that were used as flooring in one area as well as a decorative wainscoting feature inside.
Exterior decorations
At the official opening of the building in January 2009, Chris Magwood, the teacher of the Flemming College design program who created this project, will be receiving a 2008 Excellence in Education Award from the Canada Mortgage and Housing Corporation (CMHC).
Interior - Strawbale Columns with first layer earth plaster
Tags: Madoc Performing Arts Centre, Natural Building, Strawbale