In previous postings we have discussed some of the design rationale and construction methodologies employed and advocated by our company. This is a more detailed analysis of technologies and materials used from foundation to roof.
Not too long ago the construction of a straw bale house involved the design of a custom foundation, sometimes complex and unorthodox framing, shimming trusses and rafters on an undulating box beam on a load bearing straw bale wall, and a host of other quirky construction methods not often encountered by professional builders and home owners. Part to our mandate has been to make straw bale construction simpler and more accessible.
Most of the homes we design are constructed on conventional basements; an eight inch concrete wall and strip footings with a standard I joist floor system. This is the same foundation most standard … Read More »
There are essentially two methods of constructing bale walls to support the roof structure and multi-storey walls (to a maximum of 3 storeys) in residential construction. They are:
load bearing wall assemblies
non-load bearing wall assemblies
Both systems have their advantages and challenges. We have chosen to focus our efforts on non-load bearing straw bale for a number of reasons. Moisture is the biggest enemy of straw bales during construction, and until a roof is constructed the bales are vulnerable to damage even when stuccoed. Load bearing bale walls must be compressed, leveled and stuccoed before second floor or roof assemblies are constructed.
Both non-load bearing and load bearing walls can be constructed on conventional basements with an engineered i-joist floor system, grade beams, reinforced slabs and rubble trench foundations. It is at this point the construction methodologies diverge.
Non-load bearing … Read More »
Straw bales as a choice in new housing is distinctly different from virtually all new products developed to enhance the efficiency of home construction from a structural, energy, environmental or cost efficiency perspective. New building products are often developed by large companies through research and development, then marketed, branded and patented. Straw bale, and its applications in house construction, is a grass roots technology, developed by small builders, home owners and ‘do-it-yourself-ers’ exploring a means of providing housing that is cost effective using local, renewable materials for energy-efficient, healthy homes.
Testing in Canada by CMHC and other housing certification agencies in the United States (with ASTM testing) have confirmed and quantified the many exceptional qualities of straw bale construction such as fire resistance, insulation properties, and sound attenuation. The technology is not propitiatory, brandable or patentable by any individual … Read More »
The two most common questions we encounter from individuals exploring straw bales as a building option are: “Do they pose a fire hazard?” and “Are they going to be a haven for mice and vermin?” This is a cursory overview of both issues which we will be dealing with in much more detail in future postings.
Straw bales are naturally fire resistant. The dry straw that makes up the bale is very combustible when loose, but compressed in the form of a bale, the straw does not trap enough air to allow easy or rapid combustion. Building-grade bales will burn and char on the surface but their density resists combustion. Straw bales are never left exposed on any sides in a properly designed straw bale building. There is a layer of cement-lime stucco on both sides of the walls along with … Read More »
A commentary in the recent edition of Fine Homebuilding Magazine’s ‘Energy-Smart Homes’ (Winter 2013) points out the need for more homes designed and built with energy-efficiency and other sustainable principles that are within the reach of the average home owner.
Residential designer and project manager Michael Maines explains the premise of the ‘Pretty Good House’, “It’s about finding the sweet spot between initial cost and long-term savings, paying attention to critical details while maintaining ease of construction, providing energy-efficiency without ignoring aesthetics, and allowing for comfort while maintaining reasonable size.”
Programs like Leadership in Energy and Environmental Design (LEED) and Passivhaus Institute are examples of building standards achieving the highest levels when it comes to sustainability. While they are admirable targets for many buildings, your average home owner may not have the desire or budget to attain or adhere to the strict … Read More »
Introducing our latest straw bale infill project in Edmonton! The McKernan Duo project was designed for local developer Kanoo Developments and is now under construction at 10973 76 Avenue.
Form and function marry environmental responsibility. It features open floor plans to encourage family, entertaining and accommodate more intimate spaces. Transitional spaces between indoors and outdoors, adequate natural light, views & privacy, sheltered entries and the defining of public and private spaces are our attention and focus.
Each 2 storey unit is 1367 sq. ft. featuring 2 bedrooms plus flex space, 2 1/2 bath. McKernan Duo semi-detached is designed to take full advantage of its southern exposure with substantial glazing that provides light in the winter, passive solar gain in the shoulder seasons and overhangs and sunshades to reduce heating during the summer. Generous windowing on both floors allows for natural light and … Read More »
Edmonton Journal – April 7, 2012
Dave and Carol moved into the home in April 2010. Before they found it, they’d been looking at lofts downtown. Parking was an issue. But neither of them wanted a “cookie-cutter” home. They wanted something unique. And they wanted to live centrally in an area with cultural amenities and/or mature trees.
“I just didn’t want to have to drive the Henday to get anywhere,” says Caroline.
Dave happened to see a discussion about straw-bale housing on a local website and contacted Battle Lake Design Group the next day.
They’ve now fallen in love with their two-storey, 1,200-square-foot, Mill Creek-area triplex and are building another bedroom in the unfinished basement. Their family might expand one day.
“We wouldn’t want to move,” says Dave.
Read More: http://www.edmontonjournal.com/homes/Straw+bale+home+designed+future/6398315/story.html
Private Residence, 2005
Stevenson Residence owner-built project, 2011.
Framing and box columns under construction (May 2011)
Framing and box column installation (May 2011)
East side and wrap-around veranda deck
Finished exterior stucco over straw bales
Straw bale interior ‘columns’ frame the terrace doors
Proposed Devon Professional Building exterior facade renovation, Unbuilt.
The Mill Creek Flex Homes’ project purpose was to develop sustainable residential infill within the inner city. This three-unit, 2-storey row housing fits into the City of Edmonton’s vision of higher urban density in the “core,” while complementing the existing neighbourhood’s built form. The development’s location and proximity to local amenities increases the desirability and livability of the project.
The building design creates open, functional public and private interior spaces on a small footprint. It is designed and constructed to showcase a contemporary, modern straw bale building in an urban setting. Collaborative design solutions using straw bale technology were developed for the challenges of the Alberta climate.
Cement-lime stucco and vertical cedar siding create a contemporary exterior that embraces traditional building materials and techniques. Organic, textured straw bale walls, exposed structural wood and concrete, as well as extensive glazing, form the basis … Read More »