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Rob Dumont

posted Apr 14, 2014, 10:06 AM by ASHRAE Saskatoon   [ updated Apr 14, 2014, 10:17 AM ]

In a previous column I put down some Directives for a Decent, Energy Efficient Home. The Directives are meant for cold climate houses and other dwellings in Canada, the northern United States and other high latitude environments. Some of the directives would not be appropriate for warm or tropical climates.

 The issue of designing appropriate housing is an age-old issue. Socrates , who lived from 470 to 399 B.C. at a time when there was a shortage of firewood in Greece, is quoted as follows by Xenophon,” … his dictum about houses… was a lesson in the art of building houses as they ought to be. Now in houses with a south aspect, the sun’s rays penetrate into the Porticoes (porches) in winter, but in the summer the path of the sun is right over our heads and above the roof, so that there is shade.”   In our times, buildings including houses account for 40 to 50% of the total energy used in our society, and we have a social responsibility to build in a much more environmentally appropriate manner. The following directives are meant to help those wanting to build houses as “they ought to be, ” in this era of global warming.

 I passed on the previous column to a group of professionals working in the area, and asked for their comments. In this issue I am incorporating most of their recommendations for changes and improvements to the Directives. The individuals who commented are Peter Amerongen, Martin Holladay, David Olivier, Gary Proskiw, Monty Samson, Ronn Lepage, Harold Orr, Marc Rosenbaum, Tony Korte, Ken Kelln, Angie Bugg, Juergen Korn, Ken Guido, Chris Richards, and Tim Mayo.  My thanks are extended to these folks for their inputs. The following revised directives have been influenced by their comments, but I take full responsibility for the changes that have been incorporated. I have tried to keep the directives relatively short, and thus have not included any diagrams or lengthy explanations. I do not mention any brand names of products, but I can recommend the Consumer Reports Magazine and Buyers Guide as guides to efficient and generally reliable products. The Energy Star Web site www.energystar.gov/products is also a useful guide to energy efficient products. For potable water saving devices, have a look at www.epa.gov/WaterSense/products/.

 When designing and building, make sure that all applicable building, plumbing and electrical codes are applied. (Remember as well that these codes are generally minimum standards for health, safety and structural sufficiency.  The Directives listed below recommend higher than minimum standards in many areas.)

 A 1982 publication (The Energy Efficient Housing Construction Book, CMHC, 1982) listed four principles that should be used with energy efficient housing construction.

 1.      High levels of insulation

 2.   Airtight construction

 3.      Controlled air management

  4.      Passive solar design

 These four principles have stood the test of time. There are, however, some additional principles that should be added to the list.

 5.      Low energy use LAME (Lights, Appliances and Miscellaneous Electricity)

  6.      High efficiency space heating and domestic hot water equipment.

   7.      Planning of the house so that renewable energy sources such as photovoltaic panels and solar thermal collectors can be readily added.

Here are the revised Directives, including some suggestions about water use efficiency, safety, sustainability, and durability.

 1.      Design.  Do not scrimp on design. Design fees are a small part of the overall cost of a new home. Be prepared to pay 5 to 10% or more of the construction cost for a good design. Do not use plan books or standard plans. Too often the designs will not work for energy efficiency, for your location, or for your lot choice. For comparison, the real estate fees alone on the purchase of a house are typically about 5% of the house cost including the price of the land.“The bitter taste of poor quality lingers much longer than the initial sweetness of a low price.” So wrote John Stanhope. The quote applies to many purchases in life, and especially to house design. For most people, their largest single investment will be their house, and it pays to get the design right. Choose a designer with proven experience with energy efficient design. Ask to see some samples of their work. A good designer can often save you money. The key to good design of an energy efficient home is balance.  While there are many things which can be done to save energy, the costs and benefits of the various options vary tremendously.  A good designer should be able to select those upgrade options which produce the greatest savings at the lowest cost. Third party verification from a recognized agency will help you benefit from the improvements when the time comes to sell the property. It will also help you avoid the pitfalls of wishfully thinking that the measures you happen to prefer will have great benefits.

 For a very useful talk on the design of very efficient houses, have a look at Peter Amerongen’s presentation on Youtube.

 http://www.youtube.com/watch?v=dE83EDZErm8   Peter, an Edmonton builder, has built more Net Zero Energy Houses in Canada as of 2014 than any other builder.

 2. Lot selection. Select a piece of land that has good solar access. The lot should have unobstructed access to the direct sun from about 8 am to 4 pm each day of the year. Watch out for solar obstructions from trees and adjacent buildings on the south, southeast and southwest sides of the lot. A wide lot facing south is definitely preferable to a narrow lot facing south. The wide lot allows for more south window and solar equipment to be installed. The lot need not face exactly south. It can face plus or minus 30 degrees of south with little loss of annual performance compared to a lot facing exactly south. On most places on the planet you can determine south either from maps, a compass, or by observing where the sun is between about 11 am and 1 pm. (Except in the extreme north or south of the planet, where there are times in their winters when the sun does not rise above the horizon.) The Greek author Aeschylus, writing some 2500 years ago, suggested that a south-facing orientation was a normal characteristic of newer Greek homes at that time. At that time Greece was suffering a shortage of wood energy because of deforestation.  A south facing orientation was a sign of a “modern” or “civilized dwelling”, as opposed to homes built by “primitives” and “barbarians”. (A Golden Thread: 2500 years of Solar Architecture and Technology, Butti and Perlin,1980)

 3. House Shape. Choose a shape for the house that is roughly rectangular with the long axis of the house running east and west. Avoid house plan shapes that are L shaped, T shaped or U shaped. Avoid “bonus rooms” over top of an attached garage. It is difficult to provide space heating, ventilation, plumbing, and fire separations for such spaces. The L, T and U shaped houses have more surface area and heat loss for the volume that they enclose compared with a rectangular shaped house plan. Long, narrow, trailer- shaped houses should also be avoided for the same reason.

 4. Design for flexibility. A well designed house should last for centuries, and over that length of time many different uses will be made of the space in the home. As an example, provide a separate entrance to the basement of the house and design the basement space so that a kitchen, bathroom and living space can be incorporated at a later date. Another approach is to design an upper story of the house with a separate entrance and living space. Have the plumbing and electrical systems roughed in so that a separate suite can be readily developed at a later date.  Have a look at the CMHC document on Flex Housing https://www03.cmhc-schl.gc.ca/catalog/productDetail.cfm?cat=17&itm=9&lang=en&fr=1387476360672   Make sure that all codes regarding zoning, spatial separations and safety are respected.  In general, space above ground is much more useful and valued than space below ground. Basement spaces can have problems with privacy, security, and water entry through windows and walls. The separate suite spaces should be developed so that a heating system can control the temperature in the suite independently of the temperature in the other living space. For accessibility reasons, have the main floor entrance of the house at grade level. As people age, there is a greater need to avoid stairs. Plan ahead so that stairs are minimized and an elevator or powered stairlift can be readily added at a later time. Avoid details like sunken floors, with their accident-prone stairs or changes in elevation. Design the entry, hallways, doors, kitchen, bathroom and at least one bedroom to accommodate a wheelchair.  Provide grab bars.  Colour can be used to increase visibility of tripping hazards.  There are many other features that could be added to improve livability and safety for those with physical challenges.

 Good design is not easy. Combining a grade level entrance to the main floor with windows in the basement takes some creativity in the exterior grading.

 5. Trees. Some books on house design suggest placing deciduous (leaf-bearing) trees on the south side of the house and evergreen (needle bearing) trees on the north side of the house. The author does not agree with placing deciduous trees on the south side for the following reason: Many trees will grow to a great height and block the sun on the south side of the house. Although leaves will fall off in the heating season, the branches do not fall off, and a good part of the sun’s rays will be obstructed by the tree branches. A modest number of dwarf evergreen trees on the north side is all right.

 If you must have deciduous trees, choose dwarf varieties that will not block the sun summer or winter. All trees should be located a good distance from the house to prevent leaves and needles from settling on the roof and plugging the eavestroughs (gutters) and downspouts. Never have a tree that overhangs the house or garage; in major windstorms the tree can crash into the building. Also, during high wind storms or ice storms electric power outages often occur because of trees striking the power lines.

 6. Garage Type If you want a garage and have the space on the property, a detached garage is preferable compared with an attached garage for safety reasons. People have died in homes with attached garages from car motors running and producing carbon monoxide which drifts into the living space. Some people also store highly flammable and toxic materials such as gasoline cans, propane cylinders, fertilizer, herbicides, solvents, and pesticides in garages. Cars have been known to spontaneously start on fire from an electrical short. I have witnessed such a fire. If you choose an attached garage, make sure than an excellent air barrier and fire barrier are incorporated between the garage and the living space, and that you have a carbon monoxide sensor in the living area.  I almost lost an uncle whose car was accidentally left running in an attached garage. The carbon monoxide fumes from the car engine entered the house and nearly killed the occupants. Some years ago a lady in Alberta was killed by such an accident. The car in the attached garage was accidentally started by a remote starter. Here is a comment from one of the reviewers:” The remote starter is a dangerous thing.  I bought a used vehicle with a remote start function.  A few times I came to a running car after having left it for some time.  Something in my pocket must have triggered the remote starter.  I disabled the remote start feature on the car for this reason.  I can believe this must happen when cars are parked inside (of garages) too – kids playing with their parents’ keys, remotes triggered by other things in a pocket or purse….” 

 Make sure that an electrical outlet is placed in the garage or close to where a car would be parked so that electric cars can be charged once electric cars are more widely available. Have a look at the following for more information on electric vehicle chargers: http://www.plugincars.com/quick-guide-buying-your-first-home-ev-charger-126875.html

 A 40 amp 240 volt circuit is usually the minimum needed for a fast charger. For a slow charger, a 15 amp 120 volt circuit is usually sufficient.

 7. Contractors   Choose a contractor with experience in building energy efficient construction such as R-2000 Houses. Make sure that the contractor has input on the design and knows enough to be reasonably competent with all aspects of the houses:  building enclosure, heating, ventilation, electrical, controls.   The contractor should also understand the principles of house-as-a-system to prevent backdrafting of chimneys from excessive negative pressures in the house.

 8. Windows   Choose windows with great care. Windows are usually the most expensive part of the walls of the house on a cost per unit area basis. On the south side, put windows with an area equal to about 6 to 8% of the floor area of the house. Thus if the floor area of the main floor of your house is 1000 square feet (93 square metres), the south window area for that floor should be in the range of 60 to 80 square feet.(5.6 to 7.4 square metres) . A more exact formula for sizing south windows is the following: For houses with conventional wood frame construction and gypsum board interior finishes,  the south window area  should be sized using the following formula:

South window area = 8% of floor area * 0.66/ solar heat gain coefficient of the south window.  (The solar heat gain coefficient is the fraction of the solar radiation striking the window that enters through the glazing and becomes heat gain.) Approximate values for the solar heat gain coefficients of common types of windows used in colder climates are shown in the following table

Window Type

Solar Heat Gain Coefficient

(SHGC)

Double glazed, clear glass with no low e coatings

0.66

Double glazed with one low e coating(e= 0.1 on surface  3

0.55

 

 

Triple glazed clear glass with no low e coatings

0.62

Triple glazed with one low e coating (e= 0.2 on surface 2

0.57

Triple glazed with two low e coatings (e=0.1 on surfaces 2 and 5)

0.38

 Note: All windows in the above table are assumed to be fixed (non-operable) with non-metallic frames with individual glass thicknesses of 1/8 inch (3 mm) Source: ASHRAE Handbook of Fundamentals, 2005.  The surfaces count from the outside in. Thus surface 3 on a double glazed window would be the outside surface of the inner glazing layer.

 Using south windows that exceed the size suggested in the above formula will result in overheating of the house unless additional thermal mass is incorporated. The time of the year that overheating will occur will likely be in late September and early October, when outdoor temperatures are relatively warm and the solar gains from windows on sunny days are significant. The CMHC publication Tap the Sun, listed in the Bibliography, has more information on this subject.

 Fixed windows are preferable to operable windows (windows that open) and are usually less expensive and have narrower frames and admit more light and solar energy. For egress and summer ventilation/cooling, operable windows are usually incorporated in most rooms. Windows that are hinged tend to have better air tightness than windows that slide. However, hinged windows tend to have more problems with window opening hardware such as cranks. (One architect experienced with housing told me that in low income housing he was not allowed to include hinged windows; sliding windows were mandated because of the lower maintenance associated with such windows.)   On the south side, choose windows with a solar heat gain factor of 0.55 or higher. To control unwanted solar gains on south windows in the cooling season, provide a roof overhang or awning that will shade the south windows. At solar noon on June 21, the angle of the sun above the horizon is 61 degrees at locations with a latitude of 52 degrees.  At more northern locations, the corresponding sun angle would be lower. Thus at latitude 62, the sun angle at solar noon on June 21 would be 51 degrees. You can use this angle to size the external fixed shading device.  On the east and west sides, limit the window area, as windows in these orientations provide little passive solar heating in the heating season and yet contribute to overheating the house in the cooling season. Windows on the north side contribute little to useful space heating, and for this reason should be limited in area. On the east, west, and north walls, choose windows with a high R value (low U value). The HOT-2000 computer program can be used to fine tune a design for energy efficiency. Have a look at http://www.youtube.com/watch?v=-go4h75f2DQ&list=PLDAF900F4B5DF377D to see some of these passive solar principles in houses.

 9. Thermal mass. Place inexpensive thermal mass in the home. A simple way to do this is to place scrap gypsum board in the hollow wall cavities of interior wood stud wall partitions. This technique will also reduce the amount of landfill waste during construction and save on tipping fees.

 10. Insulation levels.  The author is a great believer in high insulation levels. His family home in Saskatoon was one of the best insulated houses in the world when it was built in 1992. The house has R-80 in the attic, R-60 in the above grade and basement walls, and R-35 in the basement floor joists.. The walls are about 16 inches thick (400 mm) and use blown in cellulose insulation. Details for constructing walls with high R values using wood framing and lower cost batt or cellulose insulation are available at the following web site: http://www.cmhc-schl.gc.ca/odpub/pdf/66737.pdf

 A home in Dillingham, Alaska, a cold, cloudy, northern latitude climate with high fuel prices, has even higher levels of insulation, with R-90 insulation in the walls, R140 in the attic, and R35 in the wood truss floor. Insulation in the basement floor is important. If a concrete floor slab is used in the basement, place insulation under the slab. Expanded polystyrene (beadboard) is usually the least expensive rigid insulation to use and a minimum of 3 inches (75mm) thickness should be used. Make sure that there is a thermal break around the perimeter of the slab.

 A recent paper (Proskiw and Parekh) recommends the following insulation values for homes that strive to be net zero in annual energy consumption.

 Vancouver--   R60 to R80 attic insulation; Toronto-- R80 attic insulation; Winnipeg--R80 attic insulation; Yellowknife-- R80+ attic insulation

 (To convert the above R values to RSI (metric) resistance values, divide the R value by 5.678. Thus R60 would be equal to RSI 10.6)

 Because wall insulation is more expensive than attic insulation due to additional framing or more expensive insulation materials, the above-grade and below-grade walls usually should have R values about 70% of those in the attic. Insulation in the basement floor is also important. A minimum R value of R-10 is recommended. Expanded polystyrene (beadboard) insulation is usually the least expensive insulation for this application. Higher R values can usually be justified in colder regions. A side benefit of basement floor insulation is the reduction of odour from a musty basement. The HOT-2000 computer program can be used to calculate the effectiveness of insulation.

 11. Air tightness and mechanical ventilation with heat recovery.  Build tight and ventilate right. The R-2000 air leakage standard of 1.5 air changes per hour at 50 pascals is now readily achievable by many Canadian builders, and some reviewers called for an air leakage rate as low as 0.5 air changes per hour at 50 pascals. One contractor in Canada routinely achieves 0.2 air changes per hour at 50 pascals. Have the house tested for air leakage. “What gets measured gets managed” was a key observation by Peter Drucker.

 Select a heat recovery ventilator (air to air heat exchanger) that has a low electrical consumption.. The Heating and Ventilation Institute has a web site with detailed information on the effectiveness and electricity consumption values of commonly available HRVs in North America. http://www.hvi.org/proddirectory/

 Important with heat recovery ventilators are high efficiency (effectiveness), appropriate sizing, air balancing after installation, and the ability to adjust between high and low speed as ventilation needs increase or decrease.  Spare parts availability and knowledgeable service  personnel are also important.

 The author’s house used building materials that have low offgassing of volatile organic compounds (VOCs) and formaldehyde. Particle board, which contains formaldehyde, was not used. Kitchen cabinets and bathroom vanities had the frames made of birch plywood instead of particle board.  Prefinished hardwood floors were nailed to the subfloor. No wall to wall carpets were used. Some smaller area rugs are used.  Wall and ceiling paints that have low offgassing of VOCs were chosen. Ceramic tiles were used instead of vinyl sheet flooring. As my mother often said to me, “If you don’t make a mess, you don’t have to clean it up.” The solution to pollution is not dilution, but source control.

 The preferred type of vacuum cleaner is a central vacuum that vents to the outdoors. Most regular vacuums tend to blow a lot of dust around the house. A central vacuum does not have this problem. At the framing stage, rough in the plastic ducts for a future central vacuum to be installed.

 12. Efficient Water Use. 

 Domestic Hot Water Use. The domestic hot water (DHW) load is usually the second largest energy load in houses after space heating. To reduce the DHW load, the following measures are recommended:

 1.                Low flow shower heads. In the U.S. the EPA has a WaterSenseTM  program to identify water saving shower heads. To qualify, the showerheads must use less than 2.0 US gallons per minute (7.6 litres per minute) at a water pressure of 80 psi. Some brands have an integral shut-off valve in the shower head that allows you to save water while you are soaping yourself. They are sometimes called “Navy Showers”.

 2.                Energy Star clothes washer (Tier III)

 3.                Energy Star dishwasher (Tier III)

 4.                Drain water heat exchanger (see the Wikipedia web site for further information  on these simple, reliable devices http://en.wikipedia.org/wiki/Water_heat_recycling)  and http://www.youtube.com/watch?v=8YTWHdkiVvA&list=PLDAF900F4B5DF377D

 5.                Extra insulation on the water heater storage tank, and pipe insulation on the hot water lines. By adding R28 insulation to the outside of  his tank type water heater and placing pipe insulation for the first meter of both  the cold and hot water pipes to and from  the water heater, the author reduced  the standby heat loss from 100 watts to 25watts on a 40 gallon electric water heater tank. Be very careful when adding an insulation blanket to a fuel- fired tank water heater, as blocking the air flow through the combustion chamber and air dilution inlet could result in carbon monoxide production.  A better alternative is to choose a well insulated tank type water heater. One manufacturer in the U.S. offers  non-metallic electric tanks that are well insulated and have Energy Factor (EF) values in the range of 0.9 to 0.94. A Canadian company that rents water heaters chooses that brand in large part because of the low maintenance requirements and absence of the need for anode rods. In California, commercial water heater tanks must have a minimum insulation value of R16. 

 6.                Locate the water heater close to the end uses in the kitchen and bathrooms. This reduces the large slug of cold water that must travel from the water heater to the end use.

 7.                In larger, taller houses with a bathroom or kitchen a large distance from the water heater, it may be desirable to install a small (cottage-style) booster water heater that is well insulated in the remote location so hot water is available in seconds (rather than minutes).  As an alternative, one reviewer suggested using an electric pump and a return water line to the regular water heater from the hot water tap in a remote bathroom to allow hot water to be rapidly available. Put a timer on the pump switch to make sure that the pump does not run for more than the short time needed to bring hot water to the tap.

 8.                Use smaller diameter plumbing wherever possible.  The volume of a ¾” pipe is twice that of a ½” pipe of the same length.  The volume of a ½” pipe is about twice that of a 3/8” pipe.  If a half inch diameter pipe will do, you only need to run ½ the amount of water until it gets hot than if the pipe were ¾”.  Low flow fixtures such as low flow shower heads and aerating taps would allow smaller diameter pipe to be used compared to conventional fixtures because of the lower flow rate requirements.

  9.                High efficiency water heater.  Check the Energy Star Web Site.  http://www.energystar.gov/certified-products/

 10.             With tank type water heaters, you can extend the life of the water heater by changing the anode rod every 5 to 7 years. Make sure that there is a free space above the water heater so that the anode rod can be replaced. In locations where the water has a high mineral content, the anode rod should be changed more frequently.

 11.             Have a look at the Water Heater Handbook, which is referenced in the Bibliography, for more practical information on extending the life of water heaters.

 12.             Some municipalities including Saskatoon now require a check valve and an expansion tank on the cold water supply to the house. If the bladder in the expansion tank fails, very high pressures will develop in the plumbing system as cold water enters the tank water heater and expands. Periodically check the temperature and pressure relief valve on your tank water heater to make sure that it will function. A plugged relief valve can be very serious, and has resulted in the explosion of water tanks in a few instances. Have a look at the following video to see the effect of an exploding hot water tank. http://www.appliancevideo.com/5017/results-of-an-exploding-electric-hot-water-tank/. Make sure that the outlet from the temperature and pressure relief valve can drain to the sewer and not on expensive floor coverings.

 Cold Water Use. For qualifying products, have a look at www.epa.gov/WaterSense/products/.

 1.      Toilets are usually the single largest interior water users. Choose low water use toilets. Some toilets use a dual flush mechanism with either 3 or 6 litres per flush. One single flush toilet on the market is so well designed that it can provide a good flush with only 3 litres of water.  Make sure that your plumber is confident that the low water use toilet works well and that there are readily available repair parts in your market area.  The same comment can be made about other water using devices such as faucets and shower valves.  “If you cannot find spare parts, it is exactly the same as if they never existed.”

 2.      For extra water saving, consider a Japanese style combined sink and toilet. These units have a sink on the back of the toilet. Waste water from the sink flows into the toilet tank and is used for flushing the toilet.  A drawback is that the sink normally only provides cold water.

 3.      Choose low water use vegetation on the outside of the house using native plant materials.

 The author has used almost all of the above water conservation measures on his house in Saskatoon, and in 2012 the house used 140 cubic metres (37,000 U.S. Gallons) of water for three adults (my wife, daughter and I), a good sized vegetable garden, and a small area of grass on a 6000 square foot (558 square metre) lot. An article on the house is available at http://futureproofmybuilding.com/wp-content/uploads/2013/01/The_Best-Insulated_House_in_the_World.pdf  and shows the low water use landscaping (a rock garden with native evergreen plants) at the front of the house.

 Conventional houses in Saskatoon average about 306 cubic metres of water use per year or 2.2 times as much as our consumption. Water charges currently amount to about $2.07 per cubic metre in Saskatoon plus monthly service charges. At the current water price, we have an annual saving of $344 from the water conservation measures. Over a 25 year mortgage, the water savings amount to about $8600.

 13.  High Efficiency Lighting.  Use natural lighting, light the task rather than the whole room, and use light coloured walls and ceilings.

 Compact fluorescent lamps (CFLs) and light emitting diode (LED) lamps are recommended. Choose Energy Star rated lamps. LED lamps are preferred as they typically have a longer life than CFLs and do not contain any mercury. Most LED lamps are also dimmable and can be used outdoors. Choose warm white LED Lamps with light output levels of 80 to 100 lumens per watt. Many currently available LED lamps in most stores produce less than 50 lumens/watt.  As with any lamps, be sure that they are suitable for enclosed light fixtures. Enclosed light fixtures will build up heat and can damage many lamps. Large, linear fluorescent lamps (2 or 4 foot long T8 lamps) are all right for some applications in a home, but when the ballast fails an electrician is often required.

 13.             Energy Star Appliances (refrigerator, freezer, dishwasher, and clothes washer) are recommended. Look for Tier III Energy Star Appliances for the best efficiency. http://housewares.about.com/od/majorappliances/f/CEEtiercertification.htm

 Front loading clothes washers tend to have higher spin speeds and remove more moisture than top loading clothes washers, resulting in less energy used for clothes drying. Consider a drying rack in addition to a regular clothes dryer. My sister claims there are two big benefits to the drying rack—energy is saved and the clothes do not wear out as much.  Washed towels, however, take a considerable amount of time to dry out on a rack. The drying rack also adds moisture to the house air, which may be a problem if there are other large moisture sources in the house. As the bathrooms should be continuously vented to an HRV, moisture generated from a drying rack can be vented to outdoors with some heat recovery in the HRV. An outdoor clothes line is also an option for part of the year. A conventional electric clothes dryer is usually the largest consumer of electrical energy of all the appliances in a house. Many homeowners like to have the clothes washer and dryer located in a bathroom close to the bedrooms of the house or adjacent to a hallway close to the bedrooms. To conserve space, use a stacked washer and dryer combination. 

 In the author’s family house over a one year period, the electricity consumption for LAME (Lights, Appliances and Miscellaneous Electricity excluding space heating and domestic hot water) amounted to 4086 kilowatt-hours (kWh). We have a full complement of white appliances including an electric oven and rangetop, Energy Star refrigerator, separate Energy Star chest freezer, Energy Star Dishwasher, and Energy Star Front Loading Clothes Washer. The average household in Saskatchewan uses 8340 kWh a year for LAME according to Statistics Canada. At the current electricity price of 13.8 cents per kWh including GST, we have saved about $549 a year compared with the average Saskatchewan house by using less than half as much electricity for LAME. In addition to the Energy Star appliances and entertainment products, we use compact fluorescent lamps, and light emitting diode lamps in our house. The exterior light fixture on our most frequently used exterior door is a motion sensor activated light. We also have a detached garage that is insulated (but not heated), and normally we do not use a block heater to keep the engine warm for starting. In sustained cold weather we use a timer on the block heater so that the block heater is only on for about 3 hours overnight. (In Saskatoon in January, the average outdoor temperature is about -18 oC [0oF]  and temperatures will occasionally fall to about  -35 oC  [-31o F] or slightly colder.)

 Over a 25 year mortgage life, the savings on LAME in our house amount to $13,725. (If you are using electric heat for space heating, the savings would be less, as the heat released from conventional appliances is mostly useful for space heating during the heating season. In our house, the space heating season extends only from about October to May. From June through September, there is normally no auxiliary space heating required, as the energy conservation features in the house along with small heat gains from the appliances and lights provide sufficient heat. A small amount of heat is also provided by passive solar gains from windows. Heat released from appliances and lights during that period just adds to the cooling load.)

 Keep the space heating and water heating systems simple. "While there may be a temptation to use every thermodynamic opportunity to maximize performance, the reality is that complex mechanical systems almost always prove to be problematic, expensive and far too unreliable (and often do not deliver the promised efficiency). .  Perhaps the most trouble-prone example has been seasonal heat storage systems which attempt to capture and store large amounts of energy between seasons.  “While technically feasible, such systems are usually extremely expensive, produce nominal savings and may require the homeowners to adopt a full-time repairman as a live-in family member" (Proskiw, 2008). 

 Make sure that the space heating equipment and water heating equipment are efficient and reliable yet do not require unusual professional maintenance. For instance, some instantaneous, tankless water heaters incorporate heat exchangers that must be acid washed each year by a professional to remove scale buildup from the water in the heat exchanger in order to keep the unit operating properly and the efficiency high. In areas with high mineral content in the water this scale buildup is a serious problem. The cost of the regular visit by a professional plumber to do the acid wash will most likely exceed the saving in energy costs. Consult with a space heating and plumbing contractor or other specialist to select equipment available in your town or city with a track record of efficiency, reliability and low maintenance.  The Energy Star web site has a listing of heating and domestic hot water equipment with certified high efficiency.  http://www.energystar.gov/certified-products/

 14.             Auxiliary space heating equipment. With very energy efficient houses, the space heating demands are modest. For instance, in the author’s  family home, which is rather large with 1100 square feet (102 square metres) per floor and 3 floors (two storeys plus a full basement), the peak space heating requirement is 5.5 kilowatts (18,800 BTU/hour) at -34 C (-30 F).  For comparison purposes, the 4 electric elements on our range top are also rated at 5.5 kilowatts.

 The CSA standard for sizing heating equipment recommends that the furnace output be no greater than 40% higher than the peak heating requirement. It is difficult to buy an efficient furnace small enough for that low a heat output.

 Oversized heating equipment has several problems: the equipment is noisier, larger ductwork is needed,  the equipment cycles on and off too frequently, and the rapid cycling causes premature failure of  vulnerable parts such as relays and electronic igniters for fossil fuel furnaces. Short firing cycles also result in more frequent condensation inside the furnace and venting system. Condensation causes corrosion unless the parts are specially designed. Short firing cycles also mean that rooms located a good distance from a forced air furnace will not heat up, as the cold ductwork needs a long firing cycle to heat up satisfactorily.

 Some small super-insulated low energy houses have been heated with a single natural gas or propane fireplace or an oil fired space heater. These heating appliances are point sources of heating, and the heat will not be evenly distributed throughout the house if the house has multiple storeys or is divided into small rooms.  A Building America project in the New England States used point source heating in modest sized superinsulated homes. The following pdf file has more information. https://www.eeba.org/conference/2012/presentations/2012/Aldrich-Simple-Hvac.pdf.  In some of the homes, heat was moved to the second floor from the point source of heat with small, efficient fans. A 4 unit multiple residence in Regina was recently retrofit with super-insulation, improved air tightness and a heat recovery ventilator.  Each of the units in the building was supplied with a single natural gas fireplace in the living room to replace the old heating equipment.  The units were of modest size, with each having a floor area of about 1000 square feet (93 square metres). Each unit has mostly an open floor plan, except for the bedrooms and bathrooms, and heat will circulate to the rooms in each suite by natural convection as long as the doors are open.

 As a backup, each bedroom was supplied with a small, thermostatically controlled 500 watt electric baseboard heater.  (As the units are rented out, the owner told me that because the tenants pay the electricity bill but not the natural gas bill for the fireplaces, the electric baseboard heaters are rarely if ever used.)

 Another heating technology being used by some advanced designers is a mini-split heat pump designed for cold temperatures.  Several Japanese companies make these units. They also can serve as air conditioners in the cooling season.

 The author recently sized the heat loss and heating system for a net zero energy house for Vernon, BC, conditions. A whole house cold climate air source heat pump was chosen for space heating. The air source heat pump was built by a Japanese company.

 Some very low energy houses have used ground source heat pumps. However, while somewhat more efficient, these ground source heat pumps tend to be considerably more expensive than air source heat pumps.

 15. Plan for the use of renewable energy technology devices such as solar water heaters and photovoltaic panels by orienting a roof surface toward the south at a tilt angle roughly equal to the latitude angle plus or minus 20 degrees at your geographic location. (Example: Saskatoon is at latitude 52 degrees North. A south facing surface tilted between about 32 and 72 degrees from the horizontal will be close to the optimum for solar collection.)  One reviewer with experience in PV installations on the Canadian prairies stated that a 60 degree tilt angle is a good angle in the lower part of Canada. An engineer experienced with PV installations recommends that PV panels be mounted at least 6 inches (150 mm) above the roof in order to keep the PV panels cooler and more efficient. Choose PV panels that have a guarantee as to their output and are rated by a third party agency. Given Saskatchewan’s current (2014) electricity price of 13.8 cents per kilowatt- hour including GST, a low maintenance, high quality solar photovoltaic system amortized on a mortgage is now competitive with grid supplied electricity.  During the lifetime of the house, electricity generated by solar photovoltaic panels will very likely become less expensive than grid electricity in most parts of the world. Plan for it.

 16. Cooling/Air Conditioning.  The first thing to do to provide efficient cooling is to limit the sources of heat gain. Use efficient LAME (lights, appliances and miscellaneous electricity). Limit solar gains through unshaded windows, which are often a major source of unwanted heat gain during the cooling season. Unshaded west facing windows can be the worst, as they add heat during the warmest part of the day. East facing windows should also be minimized. Shading devices on the outside of the windows are much better at excluding unwanted heat than shading devices such as interior venetian blinds or curtains. With global warming, we are likely to experience hotter days, which will add to the cooling load. In many parts of Canada during the cooling season, the outdoor air temperature at night will fall below 20oC (68 oF). This cooler night air can be brought into the house to provide inexpensive cooling. In the author’s house, a window-mounted fan is used to blow this cooler outside air into the bedrooms at night.

 16. Safety. If you have any combustion appliances in the home or if you have an attached garage or you allow tobacco smoking in the house (definitely not recommended), install a carbon monoxide sensor in the living space. Placing smoke detectors in each bedroom in addition to the ones mandated by the building code is also a good idea.  Remember that the building code requirement is a minimum standard, and not a best practice standard. A younger brother of mine once started a small fire in his bed by using an incandescent lamp under the covers to do some night-time reading. He was very fortunate that he was not burned or killed, as he fell asleep with the light on.

 17. Durability. In coastal and higher rainfall areas, make sure that your walls are of a rain screen design. Don’t buy the cheapest asphalt shingles for your roof.  A lot of energy is required to replace short-lived building materials. If you are building in a rural area with limited or no fire protection services, use non-combustible siding and roofing materials.  As an extra measure, some homeowners in rural areas purchase roll-down steel shutters to protect the windows during the fire season. Trees should be no closer than about 15 metres from the house. For more information, have a look at the Firesmart principles available at the following web site: http://srd.alberta.ca/wildfire/firesmart/documents/Firesmart-HomeownersManuaYl-ProtectYourHomeFromWildfire.pdf

 To extend the life of the tank in your water heater, periodically change the anode rod, which helps to protect the steel tank from corroding. An experienced plumber told me that he had seen a tank water heater last 50 years because the anode rod was periodically replaced. Have a look at http://www.thisoldhouse.com/toh/video/0,,20047047,00.html to learn more about how to change the anode rod in a water heater. The video has a good cutaway view of a natural gas water heater, and after seeing the video you will not drink hot water directly from the tap any longer. (The scale and corrosion buildup inside the tank is a concern.) An anode rod costs about $30 plus installation as of 2013.  A new tank water heater has an installed price of about $500 to $1500.  All tanks can potentially leak. Install a drain pan underneath the tank to collect water leaks and run the drain into the sewer.

 Regularly change the air filters in your furnace and heat recovery ventilator. Furnace efficiency will be severely reduced and furnace heat exchanger failures are more common when the air filters are not regularly changed.

 Although not as dramatic as fire, moisture problems can make homes unliveable in a few short years.   If building materials are kept dry, wooden structures can last for centuries.  Europe in particular has many examples of this, including a wood stave church in Norway that dates to the 1200s.

 Anecdotally, Yukon Housing’s Technical Officers estimate that as many as 90% of the houses that they see have some moisture problems. Moisture problems may be the biggest issue in housing:  moisture from the roof, moisture around foundations, roof water draining against foundations, poor site grading and poor foundation drainage, moisture build up in the house due to poor ventilation, condensation due to air leakage and thermal bridging, ice damming, poor siding and flashing details, plumbing leaks, high water tables, flooding, capillary rise from the soil, etc. 

 Plumbing leaks can be very expensive to repair. A friend in Saskatoon had a hose break on the rubber hose that connected the hot water line to the clothes washer. Murphy’s law also cut in, and the hose break occurred on a weekend when the family was away. The clothes washer was on the second floor of the house, the house had hardwood floors, and no one checked on the house while the owners were away.  I estimate the repair costs to the ceilings and hardwood floors below the laundry room in the $10,000 range. To reduce the chance of this happening in your house, a few things can be done:

 1.      Use special hoses to the clothes washing machine that have braided stainless steel weaving on the outside to minimize the likelihood of hose breaks. The two hoses cost about $50 as of 2013.

 2.      Put a floor drain in the laundry room, and caulk the baseboards and door threshold to the floor to prevent water seeping into the base of the walls and into other rooms.

 3.      Turn the water supply to the house off when you are away and the house is unoccupied. Check your insurance policy to see how often someone must check the house when it is empty.

  A good roof overhang and drainage plane behind siding can protect the façade from rain and water ingress.  Eavestroughs with downspouts that drain away from the house, positive site drainage, and foundation drainage, and capillary breaks are all necessary to protect foundations and basement walls from getting wet.  Do not put cast in place concrete sidewalks directly against the foundation wall, as soil compaction over time will cause a cavity to exist under the sidewalk.  Water will accumulate in this cavity and may leak into the basement. In the author’s house, the sidewalks adjacent to the foundation walls were made of precast 2 inch (50 mm) thick paving blocks about 24 inches (600mm) by 30 inches (750 mm) laid over a double layer of black plastic placed over soil. The soil was graded at a 1/10 slope away from the house.

 Moisture problems can result in costly repairs, and even destroy houses.   They can affect the physical and financial health of occupants.  You could also say that it also affects people’s mental state, knowing that they have mold problems, that it may be affecting their family, but they don’t have the means to repair it. 

 Protect your house from moisture from rain and snow melt:  1 mm of rain over 1 square meter of roof results in 1 Litre of  run off, which can result in a much higher volume of soil becoming saturated. In coastal cities such as Vancouver and St. John’s, Newfoundland, about 1.5  metres(57 inches) of precipitation in the form of rain and snow will fall in a year. On a typical roof with 100 square metres (1076 square feet) of area, the annual amount of rain to be drained from the roof is 150,000 litres. Scale this up to bigger roof areas and bigger rainfalls, and much higher volumes of water will result. (However, Vancouverites and Newfoundlanders should not get too cocky with their 1.5 metres of annual average precipitation. Prince Rupert in BC averages 2.6 metres of precipitation a year. One site in the Himalayas received 22.9 metres of precipitation one year, according to the Wikipedia web site.) My home city of Saskatoon receives only about 0.4 metres (16 inches) of annual precipitation. However, at certain times as much as 4 inches (0.1metres) of rain will fall in a single day. These water amounts, small and large, must be kept well away from the foundation by careful placement of the rain water leaders and splash blocks at the base of the downspouts. Most house insurance policies do not cover surface water entry through basement windows or foundation walls. “The insurance runs out when the water runs in.” Make sure that the roof water is carried well away from the foundation. Some informed reviewers stated that the outlets from the rain water leaders should empty at least 3 metres (10 feet) away from the foundations of houses, and a positive drainage slopes should exist to move water away from the foundation. Normally the backfill against the foundation will settle, and initial slopes as high as 1 in 4 were recommended by one reviewer.   With continued global warming and higher evaporation rates from oceans and lakes, higher rainfall values are likely. Calgary and High River in Alberta experienced major flooding in 2013. Don’t build on a flood plain unless there are dykes with a proven record of protection against flooding. Do not use flooring materials below grade that are susceptible to moisture damage.

 18. Reduce phantom energy loads (the electrical loads that draw power even though the device is nominally off) by having  separate, wall mounted electrical switches and outlets to control devices like your cable box, satellite dish, internet router, and TV.

 19. Think multiple uses when designing. As mentioned above, orient the roof surface for future solar devices. A roof overhang can also serve as an exterior shade for the windows on the south side. The noted architect Frank Lloyd Wright stated that you should never put anything in a dwelling that serves only one purpose. One net zero energy house has used concrete floor toppings that provide both thermal mass and a floor surface with a polished surface. http://greenedmonton.ca/mcnzh-finished-concrete-floors Stamped and coloured concrete is another possible alternative. Use water collected on the roof for irrigation. A rain barrel is an inexpensive technology. A typical rain barrel will store about 45 imperial gallons( 204  litres). This is not a large amount. One manufacturer is planning to produce 300 gallon (1360 litre) rain barrels.

 20.  Recycled and low impact building materials. In the author’s home, cellulose insulation was used throughout. About 16,000 pounds (7,300 kg) of cellulose insulation were used in the house. Cellulose insulation is made from recycled newspaper with a fire retardant added. Wood based products have the advantage that they generally take less energy to produce than competing products. Wood products are about 50% carbon by weight, and this carbon  is extracted  from the carbon dioxide in the earth’s atmosphere during photosynthesis as the trees grow, reducing this greenhouse gas. Wood generally has a lower embodied energy than steel or concrete.

 The author’s house used a lot of wood materials including cedar shakes on the roof, pre-finished hardboard siding with a 25 year warranty, a preserved wood foundation, and hardwood floors. In addition to the conventional wood framing materials, birch plywood frames for the kitchen cabinets and vanities, and wooden interior doors were used. The exterior front and back steps of the house have treads made of recycled polyethylene.  The treads have the advantage that the colour is integral with the material, and painting has not been required, even after 17 years of service. The detached garage for the house was recycled from a small (500 square foot) 1920s house that was originally on the front of the lot. My building contractor estimated that we had a saving of about $5,000 by reusing the old house as a garage. No heavy imported materials such as granite counter-tops were used in the house.

In summary, a good house design should make use of strong energy and water conservation measures, use passive solar heating, be adaptable in space use, use low impact materials for construction, and plan for the eventual use of more renewable energy devices such as photovoltaic panels and solar water heaters.

Here is a table summarizing the energy and water savings that the author has achieved in his family’s house in Saskatoon compared with conventional houses in the same location. The measured data for the Dumont Residence are for 2012, when three adults (two parents and a daughter) were in the house. During 2012 there was no contribution from solar thermal collectors or photovoltaic panels. 

 

Conventional Existing

Houses in Saskatchewan

Dumont Residence

(built in 1992)

Measured data for 2012

% reduction for the Dumont Residence

Annual total purchased water consumption (cubic metres per year) (City of Saskatoon data)

306.0

140.0

54%

Annual water consumption for domestic hot water (cubic metres per year)

82.1

40.8

50%

Annual Electricity Usage for Domestic Hot water (kWh/yr)

(SaskEnergy data)

4546

2254

 

 

50%

Annual Electricity Usage for lights, appliances and miscellaneous uses excluding space heating and water heating(kWh/year) (Statistics Canada data)

8340

4086

51%

Annual Total Energy Consumption [purchased energy for space heating, water heating, lights, appliances and miscellaneous electricity per square metre of floor area] (kilowatt-hours per square metre per year)

300

56.7

81%

Table 1. Comparison of Energy and Water Consumption of Dumont Residence in Saskatoon with Conventional Existing Houses.


Third Party Certification of Energy Efficient Houses

 In Canada, there are several third party groups (R-2000TM, and Passive HouseTM) that will certify houses with energy efficiency features that substantially exceed the current minimum standards of the National Building Code. A number of builders are now able to construct these homes. These third party groups incorporate some of the Directives mentioned in this article.

 Final thoughts: The Roman architect and engineer Vitruvius, working about 2100 years ago, wrote that buildings should be designed to be “solid, useful and beautiful”.  I interpret his words to mean that buildings should be durable, make good use of the local climate, and be sufficiently economical, adaptable, and attractive that people will want to maintain the buildings for a long time. These are truly admirable goals, and ones that we should all strive to incorporate in our building designs. Let’s make our new houses “the way they ought to be,” as Socrates recommended.

 

Bibliography and References:

 A Golden Thread: 2500 years of Solar Architecture and Technology, Ken Butti and John Perlin, Cheshire Books, 1980

 A Pattern Language, Towns, Buildings, Construction, Christopher Alexander, Sara Ishikawa, Murray Silverstein and Max Jacobson,1977 (Warning: Fairly theoretical)

 Builders’ Manual, Canadian Home Builders Association, 150 Laurier Avenue West5J4, Suite 500, Ottawa, ON, K1P 5J4

 Canadian Wood Frame House Construction,  Canada Mortgage and Housing Corporation2013, http://www.cmhc-schl.gc.ca/odpub/pdf/61010.pdf?fr=1390234379115

 Case Study of a Very Low Energy House http://futureproofmybuilding.com/wp-content/uploads/2013/01/The_Best-Insulated_House_in_the_World.pdf

 Green Housing Videos. www.cmhc-schl.gc.ca/en/co/grho/grho_014.cfm

 Heating Systems for Your New Home, The Drawing Room Graphic Services Ltd. Box 86627 North Vancouver, BC V7L 4 L2  solplan @shaw.ca

 HOT-2000 Computer Program. Available free from CANMET. Use your search engine to locate.

 Not So Big House, Sarah Susanka

 Proskiw, G.  pel@mts.net and Parekh, A. Optimization of Net Zero Energy Houses, BEST 2 Conference Proceedings

 Tap the Sun, Canada Mortgage and Housing Corporation, Ottawa, ON

 The Water Heater Workbook: A Hands-on Guide to Water Heaters, 1992, Larry and Suzanne Weingarten, Elemental Enterprises, P.O. Box 928, Monterey, CA 93942, USA  

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