Oval Strawbale House

The Oval Strawbale House has been given an AWARD on April 8, 2010, in the FOUNDING CUSTOM HOME category by the Home Sweet Home Competition;

“The idea for Home Sweet Home sprouted in 2008 during the research and development of OntarioGreenSpec.ca. OntarioGreenSpec.ca is an online directory that was founded by Mindscape Innovations Group (Mindscape) in response to the overwhelming demand for information about green building products and services to serve Ontario’s growing green building market.  Mindscape, experts in green building consulting and certification, developed OntarioGreenSpec.ca as a free directory for use by the public and industry.”

“OntarioGreenSpec.ca exists to shine a bright light on the great products and services available to Ontario’s high performance builders, and to serve Ontario’s green building sector. As such, Home Sweet Home promotes the use of “home-grown” materials.  Not only does a competition entrant need to be located in Ontario, the judging criteria also gives cumulative points for Canadian, Ontarian, and local (within 800km) content, with triple points when the products in the home come from your region of Ontario.”

Elegant. Efficient. Ecological.

From early design considerations of habitat preservation and geopathic energy assessments through to the final stroke of paint, all features were considered for their effect on human health, environment and of course, comfort and beauty.

In our opinion, the Oval Strawbale House exemplifies that which soma earth ARCHITECT and the builder, Evolve Homes, strives to embody in every one of their projects, a home that is all of elegant, efficient and ecological.

Rear View

Elegant

With its elliptical shape borrowed from the natural contours of its surroundings, the house gently perches on a hillside and also based on the sacred geometry of the vesica piscis. The curved walls welcome the sun’s rays into more rooms, for more hours each day than traditional straight walls while simultaneously promoting views of a neighbouring pond. Adjacent shade trees are carefully maintained ensuring seasonal shading and provision of privacy.

Prior to construction, eco-architect, Ingrid Cryns, dowsed for the geopathic earth energy lines to find the best place to position the house to clear the bed, sitting areas for the couch & office as well as the kitchen sink. The architect and owner also identified a very large, three foot diameter, beneficial energy spot on the site and the house was placed so that this energy spot was located just inside at the corner between the living room/mediation room window and upstairs bedroom walls. A plastic line was embedded into the concrete floor slab to connect this spot to the centre of the house at the fireplace to secure the energetic centre of the house with the land. This was the most critical & significant energy enhancing aspect that was implemented. The design of the house with the two curves in plan creates an extremely strong beneficial energy. All together, this creates a very strong sense of well being, joy and calmness when inside the house that is very noticeable to anyone who visits.

Sitting Room with FSC maple floor

Inside, soft finishes including customized sculpted relief work emerging from walls and fireplace surrounds together with luxuriously deep window sills replete with tiled mosaics, complete the unique look and allow personal expression for the Owner, who assisted with design and implementation of such details.

Efficient

Careful attention was paid to sealing of all joints in the building envelope and upgraded conventional insulation. Low- or no-VOC sealants and recycled under-floor insulation, instead of virgin polystyrene, was used. Additionally, this home’s strawbale insulated exterior walls, at + R30, offers significantly better operating performance than ordinary conventional construction methods.

While insulating is important, so too is the notion of massing: using dense materials in which to store and then slowly release heat. A heavy concrete subfloor as well as 1 ½” of plaster on the interior of the bale walls, combine to provide excellent thermal storage capacity. This mass absorbs heat when it is generated via the sun or the radiant floor heat distribution system, and then gently releases this heat again as the air temperature declines. Strategic use of mass provides comfort and efficiency. Working equally well in the summer by robbing the air of its heat as well as humidity to maintain user comfort, this home has no need for mechanical air conditioning.

Masonry Heater - Designed by the Client & Architect

Integration of an historic “kachelofen”, or masonry fireplace, expands the use of mass in this home. Ordinary fireplaces or woodstoves regularly burn uncomfortably hot while also consuming wood inefficiently as up to 70% of the heat escapes through the chimney. Kachelofens incorporate many small channels into specially constructed masonry masses between the firebox and the chimney. These channels absorb the generated heat before it escapes to the chimney – improving efficiencies by a factor of 2x or 3x.

Better still, this mass radiates the captured heat for hours afterward at a slow, gentle pace, allowing the users to bask in a soft, warm glow with all the visual pleasure of an ordinary fireplace.

Meditation room fireplace

Ecological

Local sourcing and use of naturally occurring materials are vital components in reducing the impact of this home. And what could be more local then felling trees from the owner’s surrounding woodlot, milling them on site, having them kiln dried nearby then turning the finished boards into all of the interior doors, cabinet doors, window sills, stair treads and baseboard. To top it all off, literally, natural oil finishes are applied and offer long lasting protection in lieu of ordinary petrochemical based urethanes.

More than simply “low-VOC”, silicate dispersion paints – Canadian  manufactured using silica sand and natural mineral pigments – are used throughout to provide rich colour and naturally mildew-free painted wall finishes. One room was even more specially treated with a clay veneer instead of any paint at all, leaving a suede-like texture that immediately attracts attention. Additionally, some baseboard was sculpted and the fireplace face’s constructed using only earthen based plasters prepared on site from locally available clays. No cement, no polymeric binders…just rich, durable, natural materials.

Kitchen with paperstone counter

Kitchen

Additional Project Details

Energy Savings

• Typical heating energy reduction of 30-50% compared to conventional construction

• Integration into landscape and existing mature trees to provide seasonal shading

• Orientation of major windows primarily toward south & east (primary view of pond) for as much passive solar gain possible through the dense forested site

• No mechanical air conditioning required

• Significant free “daylighting” through strategically located windows to reduce light use

• Further savings in heating costs achievable by owner use of Kachelofen enhanced further if using deadfall trees from own property

• Reduction in embodied energy in building materials through combination of: local sourcing, use of reclaimed/recycled materials and materials requiring fewer processing inputs

• Fibreglass framed windows provide longer life and higher insulating ratings

• Low E coatings on window glazing reduce heat energy from the sun in summer only

• Thermal edge spacers between window panes reduce thermal bridging

• “Massing” strategically used for efficient thermal storage and heat delivery

• Efficient radiant floor heat distribution on main floor and hot water radiators on second storey

• High-efficiency condensing boiler for domestic hot water and all space heating

• High efficiency Heat Recovery Ventilator (HRV), professionally balanced on start-up

Stairs

Environmentally Preferred Materials

• Local, reused and reclaimed materials and minimally processed materials reduce embody energy inherent in ordinary construction

• Reclaimed wide plank beech flooring

• Forest Stewardship Council (FSC) certified flooring

• Clay veneer wall finishes

• Earthen-based plaster fireplace facing and embellishments

• Strawbale exterior walls complete with hand-applied plaster finish

• Solid wood flooring

• Natural oil wood finishes

• VOC-free mineral based naturally pigmented paints

• Soy based polyurethane vaulted ceiling insulation

• Simulated, long lasting (50yr warranty) cedar shake roofing invented in Canada (Enviroshake)

• Locally made mineral wool attic insulation

• Interior doors, baseboard, window sills, kitchen cabinet doors and stair treads all made by local craftspeople from trees felled adjacent to house

• Kitchen counter top made from pressed and recycled post-consumer paper waste into resilient, satin finished surface

Wood trim & door detail

Waste Reduction

• Lumber off-cuts stored and sorted for reuse later in project

• Construction waste streamed appropriately for local municipal recycling programs

• No general waste construction bin used on site

Transportation

• House is walkable to community centre, shopping, banks and other amenities

• Staff carpool to site to reduce commuting energy costs; some staff stay temporarily on site during construction, eliminating the need for daily commute

• A south facing Potting Room will enable off-season vegetable greens and fruit to be grown while annuals get a head start on the outdoor planting season thereby reducing reliance on shipped in foodstuffs

3Rd Party Labeling Programs Utilized

• Eco-logo™ certified drywall

• Energy Star™ rated windows

• FSC™ certified hard maple flooring

• HRI Institute™ approved heat recovery ventilator (HRV) unit

Technical Repeatability

• All materials selected currently available in the Ontario market

• Traditional trades can use existing skills applied to alternative materials

• Design strategies customized for this site and user though same rules can be applied differently as appropriate for varying circumstances

Affordability

• Super insulated, environmentally preferable straw bale wall system comparable price to ordinary frame wall with brick or stucco finish

• Site felled trees were prepared for use at similar cost to purchasing raw material with unknown provenance from ordinary lumber suppliers

• Mineral wool batt insulation costs just 5% more than fiberglass though with a higher insulating rating, easier & much healthier to install and advantageous hydro-phobic properties

• Sustainably harvested hard maple flooring with consistent clear grade ordinary maple from unknown sources at traditional retailers

• Quality, durable materials and careful construction detailing will ensure longevity of house to reduce ongoing repair and maintenance

Technical Innovation

• The builder, Evolve Builders,  has strategically systemized construction processes and details for straw bale walls to make this labour intensive building method cost-competitive with ordinary construction

• Simple, successful, repeatable “technologies” borrowed from historic building techniques then reformulated or adapted for modern expectations including: natural finishing oils for wood treatment, clay binders for wall finishes, mineral pigments for paint tinting