energy code Archives - Vancouver Architect

Step Code Five: Get Ready to Build Net-Zero Homes

Step code 5 is becoming obligatory in most municipalities in the Lower mainland.

Energy efficiency first became a part of the BC Building Code objective back in 2008. Designers’ options to comply with the requirements comprised “prescriptive” and “performance” approaches, the first being a more common choice. The specific requirements for insulation, windows, heaters, lighting, and other equipment and systems focused on individual elements rather than the whole building as a system. Such an approach led to the performance below the projected possibilities. 

In contrast to that, the “performance” approach starts from a goal. It defines the desired overall outcome and establishes a structure to achieve it. Designers and builders can use software modeling and on-site testing to check the design and demonstrate how the constructed building will meet the requirements. Then they can determine which materials or construction methods will bring optimal results. Many green-building certification programs now take this approach.

The five-step code regulation sets performance targets for new construction, grouping them into steps. The so-called Lower Steps are easy to meet, while the Upper Steps require proper knowledge and efforts. As general guidelines, these will apply across various building types and regions of the province. 

The BC Energy Step Code is meant to ensure that new buildings will perform at their best. Still, it leaves builders and homeowners more flexible options to comply with the legislation. It will support innovative and cost-effective solutions, motivating designers to incorporate cutting-edge technologies, following the progress closely. 

Expectations are that the new five-step Code will keep innovative designs, materials, and high-performance systems getting more affordable and available. The higher steps should turn to a minimum requirement by 2032 in the BC Building Code and 2030 in the National Building Code of Canada.

Vancouver architect five step code
Vancouver architect

Benefits of the Five-Step Code

In Vancouver, for instance, step 3 (lower steps) is already the minimum. But a fully efficient, net-zero level home – step 5 – is an excellent idea for a number of reasons. Besides the obvious, like downsizing bills and doing your part for environment protection, net-zero homes come with increased comfort and resale value, to mention just a few. 

Lower energy consumption reduces overall housekeeping costs and even provides protection from future increases in energy prices, up to a level. Better air quality, achieved by using mechanical ventilation and materials with lower amounts of volatile organic compounds (VOCs), means a healthier indoor environment. 

An energy-efficient building envelope improves overall comfort by maintaining steady indoor temperatures with lower variations. It’s supported by the effective use of daylight, which further reduces your electricity bill.

Moreover, reduced energy use significantly lowers greenhouse gas emissions. Increased insulation levels also reduce sound transmission from outside. Combined with passive solar design, it prevents discomforts during power outages, maintaining stable indoor temperature levels.

Last but not least, net-zero homes feature increased resale value. They are also getting sold more quickly than conventional homes.

The Five Steps

  • STEP 1: EnerGuide Rating System, Built Green Bronze: Code requirements promote a learning process. This step makes the industry more familiar with energy modeling and airtightness testing.
  • STEP 2: Built Green Silver – Making improvements to the building systems based on lessons learned from Step 1
  • STEP 3: ENERGY STAR, Built Green Gold, and Platinum. Further improvements, developing better enclosures and potentially smaller mechanical systems
  • STEP 4: R2000 – Construction of high-performance buildings based on lessons learned from the Lower Steps and facilitated by a mature market.
  • STEP 5: Passive House, Net-Zero Energy Ready

The BC Energy Step Code defines a straightforward path to achieving net-zero energy ready buildings. It starts from the basics, the enclosure-first approach, and guides to progress by helping to minimize energy demand through the use of highly efficient mechanical equipment. 

A continuous air barrier should be considered throughout the design process, to eliminate or severely minimize air leakage. As a result, the heating and cooling demands of the space get significantly lower. Designers and builders learn in the process, including feedback from energy modeling and airtightness testing. Steps 1 -3 (lower Steps) should require little to no market transformation. 

As technology availability develops, together with growing demands for better products and more efficient systems, the capacity to improve will also increase. 

Maple ridge modern home designer
Maple ridge modern home designer

How the Five-Step Code Works

The BC Energy Step Code is a series of measurable requirements. Step 1 requires confirmation that new buildings meet the existing energy-efficiency requirements, while step 5 represents a fully energy-efficient home that is net-zero energy ready. A Step 5 home is the most energy-efficient home level achievable today, and it complies with the Passive House standard.

According to the BC Building Code, all buildings belong to the two basic categories – Part 9 and Part 3. Part 9 buildings are three-story or less with a footprint of no more than 600 square meters. This category includes single-family homes, small apartment buildings, duplexes, offices, and industrial shops. For small buildings, lower steps are achievable using construction techniques and products commonly available in today’s market.

Part 3 buildings are complex, four stories and taller, with a footprint of over 600 square meters. Those are condos, larger apartment buildings, office buildings, shopping malls, hospitals, theatres, restaurants, and more.

The regulation is fully performance-based. Therefore, it doesn’t specify the materials and strategies but rather sets measurable execution targets.

The five-step Code recognizes three categories to meet: airtightness, equipment and systems, and building enclosure. The airtightness and building enclosure metrics take the enclosure-first approach, essential for minimizing heating demand. The equipment and systems metrics then define the total energy consumption of the building to establish optimal performance.

Building Envelope

Adding more insulation to walls is easy to design, build, and maintain. While new technologies might be the first thing to come to mind when looking for an energy-efficient home, it’s a good base that will ensure their performance. 

Without excellent insulation and proper enclosure, complex technology systems will not be able to perform as expected, turning more costly to operate and maintain over time. The building envelope is not only the correct path to high energy savings but also to the improvement of overall comfort and reduced noise levels. However, making major changes to the building envelope during a renovation can be difficult and costly. Hence, it’s better and more cost-effective to insulate and make the home airtight during construction.

The minimum levels of insulation are defined by R-values by Code. The minimum effective insulation levels by the BC Building Code are between R-15.8 and R-21.9. The requirements vary based on climate conditions, region, and some accessories. The Vancouver Building Bylaw, for instance, requires R-22 effective insulation since January 1, 2015.

Determining the right amount of insulation for a high-performance house depends on several factors, including the local climate, budget, and elements specific to your building. Some studies show that the optimal range comprises R-0 to R-10 under the slab, R-24 in basement walls, R-30 to R-40 for main walls, and R-60 to R-80 in the roof. Lower values are suitable for warmer coastal climates, and the higher ones apply to colder interiors and northern regions of the province.

north vancouver architects five steps code
north vancouver architects

Airtightness Testing

Airtightness testing of the building as a whole is an absolute necessity in all steps of the BC Energy Step Code. Whole-building airtightness testing utilizes blower door fans to pressurize/depressurize the building. This includes fan airflow and the pressure difference across the enclosure. The results of testing determine the overall building airtightness characteristics. 

Building airtightness is an energy model input, both at the pre-construction stage and after building completion. The steps for airtightness vary regarding the building type and size, as well as the testing standard used. Airtightness testing should be conducted by an Energy Advisor or other qualified contractor.

Mechanical Equipment and Systems

The mechanical equipment and systems have an enormous impact on the building’s energy efficiency, directly impacting overall energy consumption. The required capacity varies with the performance of the enclosure and vice versa. Heating and cooling, ventilation, water-heating systems are all part of the metrics essential for achieving net-zero levels as Step 5 of the Code. 

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Five-Step Code Is the Future

The BC Energy Step Code is a result of a desire to manage a consistent set of higher-efficiency standards for the building industry. It offers local governments a simple and effective set of guiding standards to meet energy efficiency and greenhouse gas emissions targets.

Over the coming years, the Province of British Columbia will gradually align the base BC Building Code with the BC Energy Step Code standard, with the goal to make Lower Steps a standard practice for all new construction. 

The Energy Step Code Council encourages local governments by requiring the Upper Steps for any upcoming public-building project. These buildings are meant to serve as high-profile case studies. By referencing one or more steps of the standard, you are doing more for yourself and the community than just accessing co-benefits. It is a contribution to a growing effort to dramatically reduce energy demands across the country. 

By Aryo Falakrou (My Home Designer)

North Shore Municipalities Adopt the Energy Step Code

North Shore Municipalities Adopt the Energy Step Code

North Shore municipalities adopted the Energy Step Code for new homes on July 1, 2018. What does this mean for homeowners or new home buyers?

The Step Code is an amendment to the existing BC Building Code and focuses on air tightness and insulation for new houses and is a five-step process. At this time, municipalities require homeowners to comply with step 3 of the code. That means houses that are built now on will be 20% more efficient and by the year 2032, all new homes will be required to implement all five steps. This will make the houses Net-Zero (or Net-Zero ready), which will be explained later in this article.

Under the new system, Architects/Designers will be free to recommend any wall/ roof or floor assembly for the house construction, as long as they can prove it meets the requirements of the Step of Energy Code they are aiming for.

Additionally, a certified government energy advisor will be required to advise on the assembly detail and run the tests to make sure the builder has achieved appropriate airtightness in the house.

What does airtightness do?

When our homes are heated or cooled by our mechanical systems installed in the house, the temperature difference between the inside and the outside the house will create a negative or positive pressure which forces the air inside or outside the house. This means any hole will cause a draft that pushes the conditioned (or heated) air outside. Think of the gap between your door and the floor; if we’re cooling the home in the summer, our cool air is seeping out under the door. The same happens in the winter with our heat, if we don’t block that gap between the door and the floor. This means we are cooling or heating the neighbourhood with the lost energy, which translates to money leaving our wallets.

Evolution in Building Techniques

Decades ago, home builders were building homes with a 2×4 structure, exterior clad with lath and plaster inside. Typically, the houses were smaller and occupancy was higher, but with the changes in our society, the houses have gotten bigger and bigger with occupancy shrinking.

Later, the Building Code came into force and required more insulation in the exterior envelope, which required houses to be constructed with a 2×6 structure. The lack of proper air barriers caused mold to develop and most windows, doors, floor junctions with walls and bay windows had a draft.

Now we are in new era of building techniques and technologies that helps us to build more comfortable homes.

The amount of insulation required for Step Three of the energy code is greater than the 5.5” cavity in a 2×6 structure. As a result, many designers have suggested adding a 2” insulation layer to the outer layer of the assembly before installing the siding. This method proves the required insulation value can be achieved.

Personally, my preference is to make the change from a 2×6 structure to a 2×8 one, which will provide enough room for the required insulation value. The reason for this is because when the insulation is installed on the outer layer of the house, rainscreen strips have to be installed to create airflow (to avoid water damage). The contractor has to screw the strips through 2” of insulation to 1/2”- 5/8” sheathing, which in my opinion, don’t have enough of a grip to hold on. More importantly, the building façade is connected to the building through these strips.

So that’s why I prefer the 2X8 structure which gives the total wall assembly the same thickness as the other method and provides stronger connection of facade to the structure.

Netzero home

Netzero home

Ventilation

Since the new buildings have very little air flow from outside because of airtight construction the indoor air has to maintain in high quality. That’s when HRV (Heat Recovery Ventilation) or ERV (Energy Recovery Ventilation) systems come to the rescue. These systems work around the clock in our homes to make sure the right amount of fresh air is coming into the house and the indoor air is flowing to help prevent the growth of mold in a damp environment. They also help the heated or cooled air to be distributed evenly throughout the house, making the entire house comfortable.

This would be a little different for smaller or laneway houses, which might use passive ventilation by requiring the bathroom fan to operate 24/7 along with a fresh air intake to maintain the air flow in the house.

Certified Energy Adviser (CEA)

Prior to the submission of blueprints to the municipality, the Step Code requires a Certified Energy Adviser (CEA) to confirm the exterior walls, roof, and floor assembly meet the Step Code requirements. Additionally, during construction, the CEA will do a series of tests to make sure the builder is on track to meet the requirements.

In the City of Vancouver, it is required to have an air blow test done by the CEA after the insulation has been installed, but prior to drywall going up. The CEA is required to provide the final report to environment Canada after the house is built, but prior to the occupancy permit being issued.

Construction Standards

Over the last 50 years many different standards that have been established to provide guidelines and standards to build more energy efficient houses. R2000, Built Green, LEED and Passive House are some of the most recognizable ones and some of them are on a point system that considers the entire construction process and practice. Included in the points that can be collected is the way the builder runs his/her site in terms of efficiencies in manpower, equipment, and recycling, to name a few.

Passive House is the most recent standard that has been introduced to North America from Europe. It is focused on achieving net-zero homes by designing the house with the appropriate house direction toward to sun, windows and door sizes, locations, exterior shell assembly, and airtightness. The wall thickness of a Passive House reaches up to 12” and up.

What is a Net-Zero House and How Can it be Achieved?

Step three and four of the Energy Step Code provide guidelines to achieve higher airtightness and more insulation so we use less energy to heat or cool our homes. However, the ultimate goal is to build homes that can produce the energy it consumes.

That means the power to heat/cool, to provide domestic hot water, to run small and large appliances are produced by the solar panels installed on the house or by a windmill connected to the house or any other renewable energy methods.

Is it more expensive to build? Absolutely, but, in the long run, it pays for itself and at the same time it is more comfortable to live in.

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