The Conserving Cottage
How to build or retrofit a greener getaway
by Susan Nerberg
illustrations by Greg Latimer and Amanda Reed, Levitt Goodman Architects
 Click on detailed
illustrations to enlarge.
We’ve all heard the news about climate change, and people are reacting by doing their bit for the planet.
Making your cottage more sustainable is no exception. But for many, the word “green” conjures up images of a
utilitarian, less-than-cozy retreat with unsightly solar panels strapped to the roof. Not so. And while the
off-grid cottage powered by only sun or wind is still a rarity, many energy- and water-saving principles can
be worked into any structure. So whether you’re renovating or building new, here’s what you can do to go
green.
Site selection and preparation
“The greenest thing you can do for nature is to leave it alone,” says Trevor McIvor, an architect with a
keen interest in sustainable design. “When this is not an option – as in building a cottage – minimize the
disruption.” The starting point, he says, should always be with site analysis and building placement on the
lot. The orientation (north, east, south, or west), topography, vegetation, and unique natural features, such
as exposed granite, all inform the cottage’s design, while shoreline and side lot setbacks specified in
by-laws limit its location within the site. “We tend to play off natural features, stepping the building down
existing slopes,” says McIvor, who’s spent almost a decade designing cottages and overseeing their
construction as a partner with Toronto-based Altius Architecture.
Making the cottage fit the topography – not the other way around – saves the -parcel from blasting and
extensive grading and landscaping. It also spares existing trees and other vegetation, which provide habitat
for birds, butterflies, and other wildlife. As well, a conservative approach to site work preserves as much
as possible of the ground cover and root mass, minimizing soil erosion, especially during the spring
runoff.
Keeping cool – or staying warm
 When siting the cottage, consider passive strategies for summer
cooling and winter heating to reduce energy use. “There should be no need to artificially cool a
well-designed cottage,” says McIvor. Take advantage of prevailing evening winds for cooling in summer. A wind
trap, or raised vent, on the roof pulls hot air up and out, drawing cooler air in below, while strategically
placed windows can be opened to increase cross-ventilation. Ideally, each room should have opening windows on
at least two walls. If this isn’t possible, install an opening transom window over the door (lets warm air
escape) and a lower opening on the exterior wall (draws in cool air).
To bring in natural light and for solar heating in winter, orient the cottage to the sun’s
path, with lots of glass on the south side for solar penetration. Thermal-mass flooring, such as concrete,
brick, or stone, can passively warm the cottage from October to May by absorbing heat from low-angle sun and
releasing it at night. (Thermal mass refers to a material’s ability to absorb heat energy.) But beware in
summer – without proper shading, all that radiant heat can turn the cottage into a sauna. To prevent this,
keep the sun out from June to September by building properly sized eaves (on existing cottages, eaves can be
extended when re-roofing), awnings, horizontal trellises, or exterior louvres. Once this is done, the thermal
mass helps cool the cottage in summer. “If you keep the floor shaded during the day, its temperature will be
lower than that of the air,” says Peter Busby, one of Canada’s foremost experts on green design and a
principal with Vancouver-based Busby Perkins+Will Architects. “Expose it to night air, and it will keep the
space cool all day.”
The windows themselves can either block or admit the sun’s radiant energy. Most new windows have a low-E
(low--emissivity) coating to reduce radiant heat flow. Because such windows let radiant energy in but not
out, they work best with exterior shades. On older windows without low-E coating, light-coloured blinds or
curtains reflect radiant energy out.
Another way to retrofit an existing cottage for solar gain is to add opening skylights, with shades that
block the heat while allowing light in. They open to create nighttime convective ventilation even when
there’s no wind. Ceiling fans – or a dip in the lake – do the trick on very humid days or when airflow is
stagnant.
 Proper insulation minimizes heat gain in summer and heat loss in
winter; it’s one of the best ways to curb energy use year-round. Sprayed-in-place foam and foam panels tend
to provide more R-value (resistance to heat transfer) per inch than batt or other rigid board insulation.
“But insulation performance should be looked at in a larger context,” says Paul Dowsett with Scott Morris
Architects in Toronto. “Consider how much energy it takes to make the material. Is it using non-renewable
resources? Can it be recycled at the end of its lifespan?” Commercially available green insulation can be
made from recycled glass, mineral wool, cotton, or soybeans. Whatever your choice, consider the product’s
potential for releasing harmful gases or supporting mould growth, and keep in mind that since there are
creatures that love to use some insulation as take-out bedding or live-in housing, not all types may be
suitable. Alternatives to traditional stick-frame construction include structural insulated panels (SIPs) and
insulated concrete forms (ICFs), which provide all-in-one options suitable for new cottages. Straw-bale
construction provides R-values comparable to those of super-efficient homes. “Straw bales also take less
energy to produce than most conventional insulation,” says Dowsett. “It’s a natural material that can easily
be returned to the earth at the end of its life cycle, especially if sealed with a clay-based plaster.” A
green roof – a roof structure with living plants in a layer of lightweight growing medium – is another
effective way to insulate. If you are retrofitting, start insulating at the top – roofs and attics are major
contributors to a cottage’s heat loss or gain.
Septic systems and toilets
“A properly functioning septic system, together with the maintenance of natural shoreline buffers and
protection against soil eroding into the lake, is the most important measure cottagers can take in
safeguarding their lake’s water quality,” says Gord Nielsen, an aquatic biologist in Bracebridge. “Phosphorus
from improperly treated sewage has a direct effect on the amount of algae in our lakes.” A standard
installation – consisting of a tank, an effluent distribution system, and a tile bed in which the effluent is
dispersed – is the best first option for most family cottages. (Advanced systems, which might include an
aerobic treatment tank or a bacterial culture, are designed to provide acceptable treatment in a smaller
space.)
A promising new technique to remove phosphorus from effluent (still in the early stages of implementation)
uses a specific type of soil – known as pre-Cambrian B Horizon soil – in and around the tile bed. The high
aluminum and iron content of these soils – which occur naturally on many cottage sites or can be locally
sourced – binds phosphorus chemically and physically. The septic contractor and the municipal health officer
will help you determine the best location for the tile bed; in general, the farther from the lake, the
better.
Reducing the effluent flow to the septic tile bed minimizes the risk of untreated or partially treated
water escaping. Graham Smith, also a partner at Altius, suggests installing low-flow (six-litre) or, even
better, dual-flush (three-litre/six-litre) toilets to reduce wastewater. Composting toilets, which use little
or no water, work well where a traditional septic system can’t be installed, such as on small rocky islands.
They are a sensible option when adding a second toilet, especially if the extra septic load of another
conventional toilet is a concern. But choose a composting toilet that suits your usage patterns. To function
properly, some models need to be used regularly, or the culture that does the composting dies. If use is
infrequent, an outhouse is a tried-and-true option.
Renewable energy sources
Solar panels convert sunlight into electricity via photovoltaic cells. Today’s lightweight panels can
easily be attached to just about any roof. Photovoltaic electricity generation doesn’t produce any emissions
at point of use and the power source will not run out in the foreseeable future. But consider whether your
energy needs and usage patterns make solar a wise choice: In a seasonal cottage with high energy
demands, it may not make financial sense as the upfront costs can take many years to recover. Paul Dowsett
suggests a rule of thumb – if your cottage is more than 400 metres from a power line, your bank account may
be better off with a solar or wind system than a hydro hookup.
There are also many solar water-heating systems on the market: flat plate collectors that can be
winterized and systems in which a metallic solar collector is suspended inside clear vacuum tubes. All
require a storage tank and, likely, an auxiliary water heater, which uses a small amount of energy to boost
the temperature from sun-warmed to hot, if needed.
Other renewable options include wind power and geothermal (also known as water- or ground-source) heating
and cooling. While these, like photovoltaic panels, are certainly eco-friendly, they may not be appropriate
for your cottage. Wind turbines are only cost-effective in areas with good and reliable wind (breezes are not
enough); a geothermal heating system works best in a well-insulated building with a constant, moderate demand
for heat.
Backup systems and generators
 Being green shouldn’t end when there’s a power failure. While
the conventional back--up solution – a gas generator that powers an electrical subpanel – keeps the
refrigerator and a few lights on, it also produces emissions and noise. Adding a muffler and specifying a
propane or diesel generator (that runs on biodiesel) make the backup system more environment friendly, but
there are even greener alternatives. A battery bank that’s charged by regular hydro could power a cottage for
a week, depending on its size and the cottage’s energy needs. Where smart meters are available, the charging
could be set for off-peak hours, when electricity is less costly. Battery backups can be designed to come on
automatically if there’s a power outage and create no local emissions or noise. Another option is to use
hydro for everyday cottage needs, but install a small solar or wind system just big enough to charge a
battery backup. If you also install a net metering system, as long as the batteries are charged, the excess
power from your solar or wind system goes back into the grid, saving you money on electricity bills.
In the end, says Graham Smith, dealing with power failures comes back to the cottage itself. A
well-designed structure can eliminate many of the problems cottagers try to overcome with technology (think
air conditioning or space heating), and minimize the electricity need in the first place. In the winter, for
instance, a properly insulated cottage that’s sited to take advantage of passive solar heat and equipped with
a carefully designed plumbing system should stay warm enough to keep the pipes from freezing, with little or
no artificial heating. What’s more, installing energy-efficient appliances and maximizing natural light
reduces the size, complexity, and cost of any backup system. What’s true for emergency power also goes for
the actual cottage. “The bottom line,” says Smith, “is that conservation by design is still the first and
best option to consider.”
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