The Straw Bale House is a new passive solar off-grid straw bale house. Designed as a contemporary post & beam structure located in rural Ontario, this project was featured in Projects Green Toronto and sponsored by the Toronto Society of Architects for it’s extensive and innovative use of many sustainable technologies and green design strategies. Incorporating passive solar design methods, the house is situated to the south with a thermal-glazed top-vented gallery, taking advantage of winter sun but also shaded to reduce summertime solar heat gain. Roof-mounted photovoltaic panels are incorporated as well as a solar thermal hot water system and an electricity-producing wind turbine located on-site that all together collectively harness the necessary energy to run the home off the grid. Meanwhile the structure of the home uses a frame constructed of engineered parallel strand timbers and long-span trusses to create a warm and inviting interior environment. Three exterior walls were then constructed of affordable and environmentally responsible straw bales, and the entire home is glad with solar reflective Galvalume panels.
“A lot of off-grid and environmentally friendly houses are very traditional in design, but we didn’t want that, we wanted to go very modern, very progressive. This house uses the latest technology to transform natural elements into power, and some very basic commonsense planning and material choices to hold onto that energy once we’ve got it.” – Client & Homeowner
Reduced Building Area:
The house was designed as a multifunctional open plan space with a structural grid overlay. The family plans to adapt the space over time with shelving units and partitions according to their changing needs.
The landscaping is minimal and indigenous to the site.
Recycled and Renewable Materials:
The structural columns are engineered parallel strand timbers with non-load bearing strawbale walls. Interior finish wood was harvested onsite; A durable, solar reflective and 1 00% recyclable Galvalume metal roof was installed. The roof was insulated with Roxul mineral wool insulation, manufactured from mineral slag, an industrial waste product.
Natural Ventilation+ Daylighting:
The South glazed wall was designed with sliding doors low and operable windows high to create a natural stack ventilation system. The open-concept and glazed south wall and overhangs were designed to provide minimal solar heat gain in the summer and the optimal amount in winter.
Waste Reduction, and Elimination:
Modular systems and an efficient structural concept reduced construction waste; using furnishes such as high bookshelves and strategic spatial planning of the kitchen/ bathroom core, reduced the requirement of interior partitions. The shell, strawbale walls finished with plaster, serves as the interior and exterior finish, and the concrete floor remains exposed.
Innovative Design+ Energy Efficiency:
Hunter house is 100% off-grid. i.e. it is not connected to electric grid, water, sewer or gas mains. A Load Analysis for solar collectors and wind generator was prepared by Generation Solar. Hybrid photovoltaic (PV)/wind energy system.
Solar Water Heating System;
All systems have automatic controls to regulate consumption. The radiant floor heating is separated into two zones: main living space and ancillary rooms;
Most of the lighting is Compact Fluorescent or Halogen, with a few LED lights;
Efficient Thermo-tech windows were installed for optimal performance. Features include: Low-E, argon filled, double pane, non-glare glass, Super Spacers (foamed silicon), and a highly insulative fiberglass frame.