Riverstone Retreat Centre
Retreat Centre:
“ The mediator between the head and the hands must be the heart”
-Fritz Lang’s Metropolis
The primary collaboration(s) on this project were between Econest building company (award winning
architect and author Paula Baker Laporte and builder Robert Laporte),local architect David Macaulay, local
timber framer and natural builder Joshua Thornton, local builder Randy Martin and of course the
owner/builders Ernie and Edith Martin.
None of this would have been possible without the enlightened, progressive professionalism of Our local
building inspector Ray Holliday, and sewage inspector Les Mackinnon on behalf of the municipality of West
Grey.
The Econest at the Riverstone retreat centre has been constructed using 85% low processed local (sourced
from within 40k) materials. Of this –another 80% of the materials for this project have come directly from the
building site.
This home- based on techniques of which there are many 1000 year old European specimens, will likely stand
for 500 years. Contrasted with the expected 50 year life span of even the most energy efficient homes today -
the minimal embodied energy in this home has been reduced by a factor of 10! by virtue of its construction
method.
Even using these laborious “custom from scratch” techniques- and calculating the owners sweat equity at a
rate of $20.00/hr. this home came in at $200.00 sq.ft.---very competitive in today’s market!
Philosophy
Natural building differs from green building in that the materials consume less marketing (pamphlet printing,
sample swatches etc.), processing (glues,factories,etc.), transportation, storage and showroom(lights, heat etc.)
energy.
Labour intensive conversion of local, natural materials into building materials keeps money in the local
economy. By contrast, highly processed materials available at big box hardware stores are fabricated by large
corporations in far off lands. Purchasing these materials leads to capital flight from the local community.
Local materials travel less distance and are often processed by hand or very low energy methods. This means
that they have less “embodied energy” than highly processed materials.
Local materials lead to the re-introduction of vernacular architecture, which is…architecture that reflects the
locale in which it exists. By contrast, many homes built today look the same in southern California as they do in
northern Ontario.
The use of local materials encourages the building trades to take a more craft oriented approach to building as
the process is slowed enough to reflect on the purpose of the task at hand.
Foundation
Durisol brand wood ICF (insulated concrete form) used for frost wall/ stem wall construction, made in Mitchell,
Ontario was used for the foundation walls. www.durisol.com,
Durisol has up to 78% recycled woodchips mixed with a cementitious binder. Manufactured with a mineral wool
insert, these ICF achieve R 20 and significantly reduce the use of concrete.
“Cement kilns contribute more to the world's output of carbon dioxide than aircraft and could soon be
responsible for 10 per cent of all emissions of the greenhouse gas. New calculations by an industry scientist
reveal that cement manufacturers already produce 7 per cent of global CO2 emissions—almost three times
previously published estimates—and that CO2 output is increasing faster from cement works than from any
other industrial source.”-July 19, 1997 New Scientist
Durisol is a vapour permeable wall system which requires no vapor diffusion retarder (a.k.a. vapor barrier), and
therefore is congruent with the “flow through” exterior wall design of the straw clay walls.
All the stone for the stone veneer was sourced from the property, and hand selected by Ernie and Edith Martin,
the Clients.
This stone reflects the unique geological pre-history of Grey county, with its rich fossil record of ancient sea life.
The veneer cap is from Owen Sound Ledgerock, which supplies “marble and limestone produced from high
density dolomite. Featuring colours and patterns that are visually distinct. These quarried stones are unique to
certain regions of Ontario.” www.ledgerock.com
The foundation is a floating slab –on-grade which, coupled with the Durisol frost wall significantly reduces the
amount of concrete used in the project.
Timber Frame
Designed By Joshua Thornton , of Thor’s Hammer Timber Framing- also the lead timber framer on the project.
Predominantly local white ash- the square timbers were milled by local Mennonite Dan Shetler. All of the
natural curves were selected by lead timber framer Joshua Thornton and were sourced from the fencerows of
the Riverstone Property.
The use of these curved timbers is not solely an aesthetic preference. Their use also reflects the tradition in
England, and Wales, which was historically a response to dwindling timber resources. The same can be said of
their use in this project.
Otherwise overlooked for their structural value, these pieces would normally only be considered valuable as
firewood.
This timber frame is influenced by two traditions; the Welsh “Cruck” frame typology, and the German,
“Liegenderstuhl”. This frame synthesizes these two ancient typologies to produce a frame which is both
beautiful and functional.
All timber to timber connections (joinery) are wood to wood connections, mortise and tenon joints, and lap
joints fasten with oak pegs.
The timbers have been planed and oiled with Ontario grown hemp oil supplied by Hempola. www.hempola.com
Straw Clay Walls
Walls were constructed by students of a workshop led by Robert Laporte of the Econest building company and
Joshua Thornton. www.naturalbuild.ca, www.econest.com,
Studies conducted by Joshua Thornton for the Canada Mortgage and Housing Corporation demonstrate that
straw clay has an average R-value of 1.6 per inch (about R-20 for a 12” wall with plaster skins
Loose (not baled) straw(grow on site) is combined with a loam slurry, which coats the straw in a protective
mineralizing coating, which adds longevity to the fiber..
These walls are designed to be a “flow through” wall assembly. Flow through wall assemblies are very vapour
permeable but air tight. This is sometimes referred to by the layperson as “breathable”.
This approach works in harmony with the wetting and drying of materials, as it allows moisture which does
occur within the wall assembly to dry rapidly.
This approach also helps to balance the indoor relative humidity during heating periods. This benefits occupant
health. Dry indoor climates lead to dry mucous membranes, the body’s first line of defense against virus and
bacteria.
Masonry Heater
Masonry heaters store heat. Energy from a short hot fire is stored in the thermal mass and can provide heat all
day long.
The masonry heater at Riverstone was custom designed and built by Alex Chernov. www.stovemaster.com
The main thing that distinguishes a masonry heater(from any other wood combustion device) is the ability to
store a large amount of heat. This means that you can rapidly burn a large charge of wood without overheating
your house. The heat is stored in the masonry thermal mass, and then slowly radiates into your house for the
next 18 to 24 hours. It is by far the cleanest way to burn cordwood.
If you burn wood fairly rapidly, it is a clean fuel. If you try to burn it too slowly, the fire will change from flaming
to smoldering combustion. The burning process is incomplete and produces tars. Atmospheric pollution
increases dramatically. This is important if you are planning an energy-efficient house. The average energy
demand of your house will be quite low. For most of the time, it may require only 1 to 2 kW of heat. For most
conventional woodstoves, this is below their “critical burn rate”, or the point where they start to smolder.
Masonry heaters fill the bill perfectly. If you need even a very small amount of heat, such as between seasons
when you simply want to take off the chill, you simply burn a smaller fuel charge–yet you still burn it quickly.
The large surface is never too hot to touch. You have a premium radiant heating system with a comfort level
that simply cannot be equaled by convection or forced air systems.
Septic Design
Passive tertiary treatment reducing footprint of leach field, which is advantageous for small lots or heavily treed
building sites.
Extra treatment through constructed wetland utilizing plants for natural decomposition reduces possibility of
groundwater contamination
Interior/Exterior Trim and Finishes
The straw/clay walls are plastered with an earthen plaster (marl sourced 50’ from the building)
Reclaimed maple hardwood floor upstairs
All soffit tongue and groove is red pine from the site
All the maple trim is reclaimed material. And was installed by Fred Powell and Lynne Stolzfuts.
The cabinet caracase is fabricated with a no voc (volatile organic compounds) fibreboard
The kitchen counters are ledgerock, as well as the patio floor, which is ledgerock in another form
The spa tub is a hypoallergenic air jet system which eliminates mold and mildews, unlike a re-circulated water
system, which leaves moisture in lines to cause mold and mildews.
The walls are painted with a silicate dispersion paint. Silicate Dispersion Paint is also known as Inorganic Mineral
Paint. It was developed in Germany in the late 1800s. It is anti-microbial without fungicides, and very vapour
permeable. www.eco-house.com, Supplied in Ontario by www.harvesthomes.ca
The interior doors are white ash.
All interior partitions are of wattle and daub construction, an ancient method utilizing woven twigs and the
covered with earthen plasters.
The wattle and daub partitions have a high thermal mass and act as a secondary heat sink to the masonry
heater.
Roof Insulation
The roof here at Riverstone is insulated with a spray foam called Icynene. Icynene is 100% water-blown and
does not emit harmful gases (voc’s).
Icynene contains no ozone-depleting substances and does not off-gas over time, unlike some conventional
insulation that can deteriorate, and lose it’s stated r-value as time passes. Icynene maintains its efficiency with
no loss of R-value.
Icynene creates a continuous air barrier in the walls, ceilings and floors, which minimizes the intrusion of
outdoor allergens and pollutants.
As an integrated insulation and air barrier, Icynene effectively minimizes air leakage and accompanying moisture
(air leakage accounts for as much as 99% of moisture movement in a structure).