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How we build homes in Canada has changed very little in the last 35 years: until very recently, we have been using the same wall systems with the same insulation as we did in the 1980s.
2015, a new energy efficiency requirement was introduced into the building code. The recent introduction of defined energy efficiency requirements in the building code is likely the 1st step in a series of code changes over the next 15 years. These changes will see new homes become so energy efficient that they will use 75-80% less energy than a code-built home of today. Adding solar panels will enable many homes to produce as much energy as they consume. Homes that meet this standard today are referred to as Net Zero homes.
Recently, the Canadian Home Builders Association (CHBA) launched a labelling program to help identify homes that could produce as much energy as they consume. RDC has qualified to label our new homes under the CHBA Net Zero Energy Label. I am excited to announce that we have just begun constructing the first home to qualify for this new designation.
Net Zero Energy Label projects are required to achieve a high insulation number to reduce the homes’ overall energy use. To help achieve this, RDC has partnered with a number of our Holmes Approved Homes product partners on this demonstration project. We are also showcasing some innovative products that we believe are key to building a better home. Our key partner when it comes to reducing energy will be BASF and their new HP+ Wall System.
This new wall system will allow us to achieve a very air-tight home with great insulation values for a reasonable price using standard materials. One of the great advantages of this wall system is that BASF has extensively tested it and offers a 10-year limited warranty; no other insulation manufacturer offers a guarantee on the durability of their system. The 10-year warranty is double what builders in BC are required to offer as part of the provincial-mandated warranty program.
Our project partners include BASF, Eaton Electrical, DBG Drywall, PinkWood, and Greer Spray Foam.
Over the next nine months, I will write regular posts with photos chronicling the progress of this exciting new project. I will describe the products and features that make this home affordable, comfortable, healthy, durable, and energy efficient.
This week, we started work on our footings. Note the plastic under the forms. This is to keep moisture from wicking up into the concrete foundation. While we do this on all our builds, this site is particularly concerned as significant water comes out of the hillside during heavy rains.
Moisture wick in concrete is the fundamental cause of that musty basement smell we most likely grew up with. You are smelling the mould and mildew collecting on the framing and insulation behind your drywall, which is not a very healthy condition. You will also notice the Insulated Concrete Forms (ICF) in the photo.
For more information on the benefits of ICF, please see our blog, Insulated Concrete Forms: 5 Steps to a Better Built Home.
These progressive building code changes aim to achieve a Net Zero energy standard for new homes (and all buildings) in BC by 2032.
RDC agrees with and is excited about these changes. It is working with several key industry partners to build a demonstration home highlighting how a Net Zero Home (a home that produces as much energy as it uses) can be built. However, this project is not without its challenges. The home design and orientation are not optimal for a Net Zero outcome; the design was not optimized for solar orientation; instead, the home was designed to take advantage of the lot topography and the view corridors.
As you can see from the EnerGuide Home Owner Information label shown at the top, the home modelled by the energy software Hot 2000, with the solar panels on the roof, would produce as much energy as it uses. This satisfies the goal of designing a home considered Net Zero. In our case, we are not planning on installing the solar panels immediately to achieve a Net Zero READY status.
While most of the emphasis on these super energy-efficient homes is on the energy saved, there are numerous other benefits—from improved thermal comfort to better indoor air quality. An energy-efficient home will give back in many more ways.
In today’s post, I will give an overview of the steps we use at the foundation stage to improve thermal comfort and indoor air quality while reducing energy use to meet the Net Zero standard.
But first, here are some details about our Net Zero-ready home:
Until recently, basements and crawlspaces required minimal insulation; additionally, traditional concrete foundations only required minimal waterproofing strategies. Unfortunately, this can lead to damp, mouldy, and smelling ground spaces often turned into living spaces. I am sure we all have lived in a home (or suite) that was cold, damp, and smelly. This condition can be uncomfortable and make the occupants much more susceptible to colds and flu.
This is what we recommend:
Here, you can see the various layers applied to the foundation wall. The foundation itself is poured using an Insulated Concrete Form. Then, to bump up our insulation values and improve our air tightness and waterproofing, we have added 2″ of Halo Subterra, a graphite-impregnated expanded polystyrene foam provided by Standard Building Supplies. The ICF foundation blocks have an effective insulation value of R 24; the Subterra will add R10, giving us a total effective R-value of 34.
Concrete is like a sponge; if exposed to water, it will quickly wick moisture, which can then transfer to interior framing and insulation. The high moisture/ humidity levels then promote mould and mildew, a nasty, musty basement smell we know so well!
In the photo above, if you look closely, you can see that the base of the foundation/footing is wrapped in plastic. This plastic is wrapped under the footing and will be sealed to the interior under slab insulation, ensuring the entire foundation is moisture-free. The plastic is connected to the exterior with a layer of the peel-and-stick membrane (Nudura), and the whole assembly will be protected by a plastic-dimpled membrane designed to eliminate hydrostatic pressure. Of course, we will have the required perforated pipe as a perimeter drain.
Foundation forming will be completed this week, and framing of the revolutionary HP+™ walls and XR series system will begin on March 13.
Today, I will focus on the wall systems and insulation we will use to achieve the insulation values required to build a home that can produce as much energy as it uses (with solar photovoltaic panels).
When considering building a home designed and modelled to produce as much energy as it might use, it is very important to reduce energy use as much as possible; the biggest energy demand in a Canadian home is for heating and cooling, so we must design and build a home that is airtight with very good insulation.
The wall system you choose has a big impact on your energy consumption. When RDC looked at the new BASF HP+ wall System, we knew we had found the formula for exceptional insulation performance and building air tightness.
The BASF HP+ advanced high-performance wall system uses the following products:
How does HP+ help make a home better? In addition to energy reduction, a high-performance wall system will also provide the following benefits:
The HP+ wall, at 1st glance, looks much like a conventional framed wall Until you look closely! Rather than a typical 2X6 stud, this system uses a 2X4 on a 2X6 top and bottom plate with a 2″ horizontal strapping (to make up the difference between the 2X4 stud and 2X6 plates). This significantly reduces the thermal bridging typical of a conventional stud wall, as we now only have a thermal bridge where the strapping connects to the 2x4s. We use 2.5″ of Waltite spray foam on the inside of the assembly to seal between the strapping and the 2×4 studs.
The NP1 seals all the framing connections, such as studs to plates and plates to the floor. These two elements combine to give the walls an airtight seal.
You might think that 2.5″ of spray foam does not give us much insulation, and you would be right. We would now have an effective R-value of about 12 – a long way from where we need to be.
This is where the Neopor ridged insulation comes in. We will use 4.5″ on the home’s exterior, giving us an additional R20 for a total of R32. This is where we need to be for our climate zone to achieve the energy reduction standard and a Net Zero Ready energy footprint.
– Bob Deeks & The RDC Team
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We specialize in building custom homes and renovations in the picturesque Sea-to-Sky Corridor, including Whistler, Squamish, North Vancouver, West Vancouver, and Pemberton.