At RDC we tend to use terms that reference housing that are familiar to us that sometimes can often be confusing to the average person; terms such as happy, healthy, comfortable and high-performance may mean one thing to us and another thing to you; so what is a happy healthy high performance home?
I would like to highlight one of our current projects in the new subdivision of Crumpit Woods in Squamish to help decodify what we mean. This home will achieve a very high rating for energy efficiency; this a key component in meeting our expectation of a happy healthy high-performance home.
This Crumpit Woods home is a 3000 sq ft, single family home located on a bright sunny lot with a peek-a-boo view of Howe Sound ,surrounded by a stunning vista of West Coast forests and mountains and it will be certified as an Energy Star new home and be part of our Holmes Approved Homes Certification program.
All of our homes are measured using the Hot 2000 Energy Simulation software.
This software allows us at the design stage, to predict what the energy use under normal living conditions is likely to be. Our featured project for this week is modeled to achieve an energy rating or EnerGuide rating of 87 if built with an air source heat pump for air conditioning.
To put this in context, a standard home built to the new building code energy standard in the British Columbia is intended to be around EnerGuide 78. The EnerGuide rating scale is exponential such that a rating of 87 is close to 60% more energy efficient than a modern code built home.
A healthy high-performance home is something that can only be created by incorporating certain features and design philosophies at the very beginning of the design phase. One of the first things we do is look at opportunities for a passive solar design. If we can optimize the location of our windows and incorporate passive shading into the architectural design, we can both reduce our heating costs in winter, and if careful with shading, reduce or eliminate the need for air conditioning in the summer.
As you can see from the photo taken on February 24th, 2016, the sun is streaming in from all the south facing windows. The home design was specifically chosen to optimize the south facing orientation of the lot. An excellent additional benefit is that some of the best views face south as well!
In the summer, when the sun angle is high, the roof overhangs will shade the sun such that the direct sun should only just hit the floor in the mid afternoon resulting in limited heat gain. With the very high insulation values (more on that below), as long as the doors and windows are kept closed during the heat of the day the house should stay reasonably cool without any AC.
Our next design focus is to ensure that the home is constructed to have minimal heat loss (or cooling loss in summer). There are two ways we approach this;
The first and lowest cost strategy is to ensure the home is air-tight – Note, that an air-tight home must have a good whole home ventilation strategy (more on that below). If you know what to do, air tightness can be an easy, low-cost way of dramatically reducing energy loss in both the summer and winter. An air-tight home cuts down on drafts, making the home more comfortable and, depending on the level of air-tightness, can virtually eliminate dust accumulation – hence the first step in delivering a healthy home! Air-tightness values are not something we guess at RDC.
Every home we build is tested to ensure the home meets the target set in the original Hot 2000 model and verifies that we have delivered on our commitment to a healthy home.
The second design strategy is ensuring high effective insulation values (See my post on our Georgie Award finalist Best Certified Production Home for more on effective insulation values). This house is what we would consider a super insulated home with the following insulation values:
To complete the package we need a very efficient heating and (as an option) cooling system combined with a whole home ventilation system, or as we would call it, a Heat Recovery Ventilator (HRV).
For our heating system, we will use Dettson’s small Chinook furnace with their proprietary ducting system. With this system, we get a right sized furnace (Check out my post 3 Technologies You Should Consider For Your New Home to learn more about the importance of a right sized furnace) with a whisper quiet ducting system.
The HRV will exhaust all the stale damp air from rooms such as the baths, kitchen and laundry, and deliver fresh air to all the living rooms such as bed rooms, living and dining areas. The HRV recovers a portion of the energy from the exhaust air and transfers it to the fresh incoming air – this is another key component to a healthy home; keeping the air fresh and clean smelling, exhausting all the pollutants we create indoors and controlling the humidity level.
In review a high-performance home is:
If you are interested in learning how you could build a home like this, please call or email me. I always love to talk housing.