There is one thing that EVERY homeowner has in common: we all want lower utility bills. If you are in the planning stages of a new home, GOOD NEWS – you can achieve this goal easily and with little/no extra costs (that’s right – some of these savings are completely 100% FREE)! This may seem like a complex problem involving various building assemblies, professional energy modelers, accountants to determine net present values, ROI vs. payback, etc., but there are some simple steps that can be taken to increase the efficiency of your future home.
You can scroll down to view a more detailed list of items to consider during the planning/design stage of your home, but for now I would like to compress them into a broad, 3-point list (in order of importance):
1) Design your home (including its orientation) to minimize energy requirements and maximize free energy. Reduce the building footprint by eliminating any wasted space where necessary (eg, re-configure hallway space, etc). Orient the home to maximize passive solar gain in winter, while avoiding the same in summer (ie, south facing windows should be designed with awnings/overhangs to absorb the lower winter sun, while shading the higher summer sun). Designing a home with some of these details in mind is FREE – take advantage of this knowledge! It is wise to align yourself with designers/suppliers/builders/trades that have experience building energy efficient homes early in the design stage and ask each for input prior to putting pencil to paper.
2) Make sure the building envelope is well-insulated and air-tight. Special care should be taken to eliminate thermal bridging (floor joists, headers, studs, etc). Using methods/material that contribute to an air-tight building envelope ensures you are not passively losing the air you have paid to heat! FYI - NUDURA’s design (continuous insulation on both sides of a monolithic concrete core) results in a building that is inherently air-tight (take care to properly detail openings/service penetrations) and has a high level of insulation with little/no thermal bridging. The addition of the thermal mass properties of the concrete core inside an ICF wall have shown to further increase the performance beyond that of a low mass wall.
3) Use of “green” energy technologies. The previous 2 points are aimed at REDUCING your energy needs as much as possible. The remaining needs can be met by use of solar, wind, LED lighting, Energy Star appliances, etc. It is always in your best financial interest to eliminate the energy requirements FIRST and then worry about energy generation SECOND.
For the more comprehensive list, I am going to defer to the expertise of an absolute legend within the green building industry, the late Dr. Rob Dumont.
The following is information taken from an article by Dr. Dumont in the September 2013 edition of Solplan Review. If you are not familiar with the work of Dr. Dumont, he was a superstar in the world of energy efficient building and design. His work on the Saskatchewan Conservation House, the Factor 9 Home, and his own personal residence in Saskatoon, SK (which was the best insulated house in the world!) among others contributed to the creation of the Passivhaus and R2000 building standards. An awards banquet is held in his honor each year in Saskatoon (https://www.emtfsask.ca/awardsdinner2018.html) to recognize individuals who continue to work in advancing these interests.
So here is the checklist to follow (in order of importance):
1) Don’t scrimp on design. Be sure to hire a competent designer that can work to incorporate the following details. Remember, you get what you pay for!
2) Choose land with good solar access. Preference should be given to a lot that can accommodate a large amount of south facing exposure. Be mindful of obstructions, such as large trees or buildings that can limit passive solar gain.
3) Choose a roughly rectangular shape. This will maximize the interior volume of conditioned space vs. the exterior wall surface area. If possible, the long sides of the home should run east-west to maximize south exposure/solar gain.
4) Design for flexibility. Think of future needs, such as basement entry, separate suite, etc.
5) Detached garage is preferable. This was not included for energy efficiency, but rather safety, as Dr. Dumont expresses concerns regarding carbon monoxide poisoning from vehicles running in attached garages. Consider including a 220 volt outlet in the garage for charging an electric vehicle as they become more commonplace.
6) Choose a contractor with experience in building energy efficient homes. Also, choose the contractor at the design stage and ask for input regarding building details/design. Input from sub-trades & suppliers in their area of specialization can also be helpful (ounce of prevention….as they say!).
7) Choose windows with great care. South facing walls should have windows with an area of about 8% of the floor area of the house. Use overhangs, awnings, etc. to ensure shading of these windows in the summer (when sun is higher) but allow solar gain in winter (when sun is lower). Limit the windows facing north/east/west as these do not contribute to space heating. Consideration should be made regarding style of windows to maximize insulation value and minimize air leakage (ie, hinged style is better than sliding windows).
8) Place inexpensive thermal mass in the home. A simple (and free) option is to place scrap gypsum board in the hollow wall cavities on interior stud walls. Thermal mass is needed to absorb the passive solar heat that was gained during the day and retain/emit that free heat at night.
9) Insulation levels. Given our cold prairie climate, it is no surprise that insulation is money well spent. When Dr. Dumont built his house in Saskatoon, it included R-80 attic insulation, R-60 for above and below grade walls, and R-35 below the basement floor. Reducing/eliminating thermal bridging is imperative to achieving a well-insulated home.
10) Air tightness and mechanical ventilation with heat recovery. Be sure to design the building to be air tight at all openings/connections. When inefficient passive air movement is eliminated you must introduce mechanical ventilation to control humidity and stale air. Do so with a Heat Recovery Ventilator (HRV) that has low electrical consumption.
11) Water Efficiency. Domestic Hot Water is usually the second largest load in a home next to space heating. This can be reduced with low flow faucets, Energy Star appliances, drain water heat exchangers, high efficiency water heaters, and locating the water heater near kitchens/bathrooms.
12) High Efficiency Lighting. Light emitting diode (LED) lamps are money well spent!
13) Energy Star Appliances can reduce both power and water consumption.
14) Renewable energy sources. Even if you don’t plan on installing solar panels at time of building, consider making your home “solar-ready” for future installation. This can be as simple as a conduit from basement to attic to run a future wire. A quick call to a local solar company (we have some great one’s around Saskatchewan!) will help to determine what preparations should be made.
15) Safety. Smoke & carbon monoxide detectors are now mandated by code.
16) Durability. Build with proper materials/methods for your climate. A home is designed to perform as a SYSTEM. This system is negatively affected if a key component is not performing as expected or if it wears out prematurely.
17) Reduce phantom loads. An electrical switch can be installed to cut power to outlets controlling the TV, cable box, etc. These devices will continue to draw power even when turned off.
There you have it! Remember the 90/10 Rule when building: “90% of the results come from 10% of the effort.” This means that the remaining 10% of results are only achieved by proper planning and great care in each of the details of your home. Feel free to contact a Prairie ICF representative as you begin planning your new home. We would be happy to discuss some of the aforementioned information. We also offer NO CHARGE design assistance! By working with your designer we can adjust the wall dimensions to optimally suit NUDURA’s products, thereby reducing waste and construction time.
Don’t forget that effective January 1, 2019, Saskatchewan has adopted an Energy Code for homes (Section 9.36). Not sure what this means for you? Our previous BLOG covers this topic.
Keep these things in mind when you begin your planning. Happy building!