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Affordable Passive House on BC's West Coast

How to Build an Affordable Passive House on BC’s West Coast

British Columbia is celebrated for its stunning natural beauty, with rugged mountains, pristine forests, picturesque coastal communities, and idyllic islands like Vancouver Island and the Gulf Islands. Living on the BC West Coast, in places such as West Vancouver, Squamish, and Whistler, offers several attractive advantages.

The West Coast enjoys a mild climate, with warm summers and cool, wet winters, providing a comfortable environment for a wide range of year-round recreational activities. Residents have easy access to outdoor activities such as hiking, mountain biking, snow sports, water sports, camping, and fishing.

BC’s West Coast is also known for its exceptional post-secondary educational opportunities, with twenty-five publicly funded institutions that are composed of eleven universities, eleven colleges, and three institutes. The area has a diverse economy with thriving industries like technology, forestry, mining, and tourism that provide job opportunities and a high standard of living.

The passive house standard has gained worldwide recognition for its focus on minimizing energy consumption while maximizing comfort. However, the misconception persists that building one is prohibitively expensive. In this article, we will cover ways that careful planning, strategic sourcing of materials, and leveraging available incentives, can make building an affordable Passive House on the West Coast feasible.

What is a passive house?

The Passive House concept originated in May 1988 as a set of low-energy building principles designed to employ passive solar technologies, while maintaining exceptionally comfortable indoor temperatures, with a minimal energy requirement for heating or cooling. Early builds were based on the research and experience of North American builders during the 1970s, who were required to build homes that required little or no energy in response to the OPEC oil embargo.

Passive houses must adhere to strict building criteria and require meticulous design, which produces homes that consume up to 90% less heating and cooling energy than conventional homes. Typical energy cost savings will be approximately 60 to 80% overall. The five principles central to Passive House design and construction are:

1) super-insulated continuous insulation,
2) extreme airtightness,
3) super-efficient windows,
4) thermal-bridge-free detailing, and
5) heat recovery ventilation.

To effectively build a Passive House home, the design should be looked at holistically and incorporate all five design principles.

The building envelope separates the interior of your home from the exterior. It consists of the foundation and floors, the outside walls and the roofs. Passive house makes the most of the envelope by sealing, super-insulating and eliminating thermal bridging, to increase the thermal performance.

Your home’s air barrier is a layer of material – membrane, tape, seals – around the envelope that restricts the movement of air in and out of the building. Installing superior continuous insulation typically delivers triple the heat resistance when compared to the requirements specified in current Canadian building codes, and offers the added advantages of greater soundproofing, improved durability, and enhanced building resiliency. Thermal bridging occurs when a material bypasses the insulation, allowing heat transfer that can significantly reduce the effectiveness of the insulation.

Design phase

You will work with a Certified Passive House Designer or a Passive House Consultant who understands passive house principles and can optimize the design for energy efficiency while adhering to local building codes and climate considerations. The Passive House Planning Package (PHPP) is the building energy modelling software your designer or consultant will use, and it is an essential part of the building design process in Canada.

The PHPP will enable your home’s designer to determine the most suitable form of building for your project and evaluate the impact various design considerations will have on its energy efficiency. It can calculate the required performance level of individual components and the influence of various options on the energy balance of your home, both in the summer and winter. It can help your designer calculate the heating and cooling load, and determine the size and required performance of mechanical HVAC systems. The software can also estimate the life-cycle costs of various design options.

The PHPP can calculate energy production from onsite renewables such as solar panels and wind turbines, and the building energy needs being met by those renewables. When the design phase nears completion, the software can confirm whether your home meets the Passive House certification criteria.

Sourcing local and recycled materials

By choosing locally sourced materials, architects, designers and builders can significantly reduce the carbon footprint of their projects, while reducing costs. Legislation in BC encourages the use of pine beetle-affected wood as a building material to reduce carbon emissions associated with its decomposition or burning.

Reclaimed wood is also gaining popularity in BC as a sustainable construction material due to its unique character and environmental advantages. This wood is often sourced from old buildings, barns or other structures, church pews, and even driftwood, and repurposed for use in a new construction project as beams, plank flooring, mantels, kitchen cabinets, accent walls and ceiling panelling. Reclaimed wood can add warmth and a sense of history to your space while reducing the cost of materials.

The transportation of building materials over long distances contributes significantly to greenhouse gas emissions, air pollution and handling costs. Sustainable local sourcing helps preserve natural resources by limiting extraction to fulfilling local construction needs, and in the process helps support the local economy and businesses. Local sourcing can promote ecological balance by utilizing both renewable and recyclable materials.

British Columbia is at the forefront of innovative wood architecture, engineering and product development. BC’s abundant forests and commitment to innovation and sustainability have positioned the province as a global leader in energy-efficient, earthquake-resistant, and sustainable engineered wood products. Through the Wood First Program, the province encourages the use of wood in construction to promote climate-friendly building practices, supporting its forest-dependent communities, to grow local and global markets for value-added wood products.

Sustainable softwoods such as slash pine, bald cypress, and Douglas fir, along with hardwoods like black cherry and black locust, are fast-growing BC lumber species, with high strength-to-weight ratios that are excellent for construction projects.

Squamish quarries beautiful basalt and granite formations that are ideal for flooring, wall cladding, and kitchen or bathroom countertops. Marbles sourced from quarries on Vancouver Island deliver elegance and durability for flooring, countertops, fireplace surrounds, stairs, walls and backsplashes, and columns.

Energy-efficient systems

Mechanical systems are a key design consideration in passive house design. These homes are known as ‘passive’ houses because they are so well sealed and insulated they lose very little heated or cooled air. A comfortable interior temperature can be maintained year-round with little or no conventional heating or air conditioning.

The primary source of heating and cooling comes from sunlight delivered by the orientation of the house on the lot, shade provided by landscaping and hardscaping features, thermal mass and materials and features that reflect or absorb heat, and energy exchange and heat transfer provided by the ventilation system.

A heat recovery ventilator (HRV) is a fresh air system that removes the stale air from your home, while providing a 24/7 supply of fresh, filtered air to every room, recovering the heated or cooled air from the exhaust stream. Another option is an energy recovery ventilator (ERV) system. In addition to recovering heated or cooled air, it can also transfer water vapour from the exhaust air, which helps prevent over-drying of the indoor air during the winter.

Exhaust air is drawn from the kitchen and bathrooms, where odours, moisture and chemical pollutants collect. The air passes through the heat exchanger, where it makes its thermal energy available. Fresh intake air is drawn in from outside your home, it passes through the HRV or ERV heat exchanger, where up to 90% of the thermal energy from the exhaust air is recovered and transferred into the incoming air stream.

Construction phase

Your passive house building is wrapped with a continuous layer of thick insulation to optimize thermal comfort, reduce condensation, and enhance energy efficiency. During construction, meticulous care will be given to air sealing details, to minimize air leakage, a key requirement for meeting passive house standards.

A final blower door test result of less than 0.6 air changes per hour at 50 pascals of pressure (ACH 50) will be required to qualify for certification. Blower door tests are typically conducted throughout the construction process to identify and address any air leakage issues promptly, ensuring the building envelope’s integrity.

Advanced construction techniques, such as insulated concrete forms (ICFs) or structural insulated panels (SIPs), are often employed to mitigate thermal bridging. Conductive materials used to frame glazing systems can be a source of thermal bridging and heat transfer. Wood, fibreglass, and PVC window and door frames, with insulating air chambers, or thermally broken aluminum frames are a good solution.

Rebates and incentives

British Columbia periodically offers several rebates and incentives to encourage the construction of energy-efficient homes, including passive houses. Leveraging these programs can significantly offset the initial investment and make building a passive house more attainable:

Municipal Incentives: Some municipalities in British Columbia may offer additional incentives or fee waivers for building energy-efficient homes, in the form of Municipal Top-Ups.

FortisBC New Home Program: At this time, FortisBC is designing a New Home Program for 2024 which will address the revised DSM regulation and the building code changes.

CleanBC Better Homes New Construction Program: As of January 1, 2024, the CleanBC Better Homes New Construction Program has closed. Through the CleanBC plan, the Province of British Columbia has been supporting the adoption of the BC Energy Step Code and making energy-efficient, climate-friendly homes more affordable and accessible for British Columbians. There may be a new version of this program released at a future date.

Renewable energy: passive house meets net zero

Over the long term, the energy savings you’ll enjoy by adding a solar panel system should more than offset the cost of the system. However, if achieving the lowest construction cost is more important right now, building to Net Zero Ready is likely your best choice. You can add a renewable energy source at a later date. A net-zero energy-ready house has been designed and built to a level of performance that it would, with the addition of a solar panel renewable energy system, qualify for net-zero energy certification.

BC Hydro’s net metering program is designed for BC homeowners who generate electricity for their use. It allows you to power your own home with renewable energy, with the flexibility to rely on their power grid if you need it. When your system generates more energy than you need, your control panel will feed that power back to the grid, and you’ll receive a generation credit toward your future electricity use.

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