Passive House EnerPHit retrofit

Passive House Retrofits: Strategies and Techniques for Retrofitting Existing Homes

In British Columbia, as we head towards 2030-2032 we will rely more on clean, renewable energy and less on oil and gas to power our needs. In a typical new house today, constructed to the building code, 60 – 70 percent of the energy use will go towards heating and cooling, according to research by Dalhousie University.

The modernization of existing building stock

In the “Canada’s Climate Retrofit Mission” perspective, Brendan Haley and Ralph Torrie of Efficiency Canada state, “There is no pathway for Canada to achieve its greenhouse gas emission targets that do not include deep and widespread energy efficiency improvements to the residential and commercial building stock, combined with phasing out its fossil fuel use.”

To achieve decarbonization targets in Canada, initiatives like BC Energy Step Code (ESC) level 5 strive to compel builders to use energy modelling software and on-site testing to meet requirements of the standard, to bring all new homes up to ‘net zero ready’ by 2032. And while British Columbia is leading the charge in Canada, Journal of Building Engineering data indicates that the existing building inventory contributes to more than 18% of the total global CO2 emissions and 38% of total global energy-related emissions. Existing homes must be part of the solution.

The Canadian Climate Institute says that simply demolishing existing buildings and building new ones isn’t a pathway to net zero. Mining or harvesting of resources, manufacturing and construction create an enormous carbon debt for each new home built. Pembina Institute estimates that 70 percent of buildings standing today will still be in use as of 2050, and they’re saying that between now and 2050 we will have only one or two can’t-miss opportunities to retrofit each of these buildings.

Passive House as a path to net zero

When we hear the term “passive house” we think of energy efficiency, comfortable living spaces, indoor air quality and longevity. Passive house structures are designed to consume minimal energy and reduce both heating and cooling costs, while significantly reducing your home’s carbon footprint.

Airtight construction and superior insulation provide exceptional comfort, with constant temperatures, free from drafts and cold spots, all year round. The controlled ventilation system ensures that the air inside your home is always fresh and filtered. With a focus on building science and quality materials, your passive house will require less maintenance, so it can become part of your family’s legacy.

Passive house and net zero are two distinct concepts. Passive house is an architectural and building standard, with principles that focus on achieving optimal energy efficiency through a holistic approach to design, meticulous construction, and a plan for its ongoing operation. To achieve net zero, your total energy consumption must be equal to or less than the energy generated by renewable sources.

There’s a synergistic relationship between the two concepts when your passive house’s energy efficiency measures have reduced your home’s energy demands to a level where a small renewable energy source can cover its needs entirely. The two approaches meet in the middle.

EnerPHit certification

Research by Hurnik et al. assessed total energy use in a heating season. By using an energy simulation tool, they used an energy efficiency renovation package with a Life Cycle Cost (LCC) focus to comply with Passive House requirements. They discovered that for many existing homes, the envelope improvement to the passive house standard would be extremely expensive, making it a nearly impossible plan.

Due to extensive structural, insulation, air-tightness and thermal bridging challenges, it may not always be possible to meet the Passive House Standard that’s used for new construction, when remodelling an existing home. Even without budget constraints, such an undertaking would not be practical, or perhaps even possible.

To address the pressing need for upgrading existing buildings, the Passive House Institute (PHI) developed the “EnerPHit – Quality-Approved Energy Retrofit with Passive House Components” Certificate. Energy savings of up to 90% can be achieved in existing buildings under the EnerPHit certification program, by implementing the following measures:

  • superior thermal insulation,
  • minimizing thermal bridges,
  • an almost airtight building envelope,
  • installation of passive house-suitable triple-glazed, low-e, argon or krypton-filled windows and vault-style energy-efficient doors,
  • air ventilation with a heat recovery system
  • an efficient heat generation and cooling system, and
  • addition of renewable energy source(s), if aiming for plus or premium certification.

These are the very same measures specified in new construction to qualify for Passive House certification, but with a lowered bar that takes the age, ‘bones’ and unavoidable thermal bridges of existing structures into account.

By using passive house components, EnerPHit-certified buildings offer most of the advantages of a new passive house building to the homeowners, delivering optimal cost-effectiveness, and the option of upgrading to net zero with a renewable energy system. Certification is a means to ensure quality control during the entire design and planning process, making it easier for your design-builder to specify adequate components. The EnerPHit seal assures that optimum thermal protection has been implemented for your retrofit home.

Can I complete an EnerPHit passive house retrofit in steps?

Yes, many homeowners are unable to undertake a complete passive house retrofit all at once, but can manage the project in several phases. Often, a high level of energy efficiency can be achieved in the first phase, at a very reasonable cost, using passive house components.

Before the project commences, a full EnerPHit Retrofit Plan (available with PHPP) should be completed, outlining the first phase, and each of the future retrofit phases to be completed later. With careful planning, involving you, your retrofit design-builder and the EnerPHit certifier, your project can proceed through the phases of completion without health or safety issues, discomfort or much inconvenience.

The retrofit plan provides a methodology that takes into account the important interrelationships between the various energy-saving measures. To begin the certification process you and your designer will engage a certifier that has been approved by the Passive House Institute.

Incentives, grants and eligible retrofits

At least eighty clean energy incentive programs are currently available across Canada. In British Columbia, there are at least 17 clean energy incentive programs, including energy efficiency incentive programs, renewable energy incentive programs and low-income and indigenous incentive programs.

As part of the Canada Greener Homes Initiative, applicants may have access to grants from $125 to $5,000, up to $600 as a maximum contribution toward pre- and post-retrofit EnerGuide evaluations, and interest-free loans of up to $40,000, with a repayment term of 10 years.

Canada Greener Homes Grants cover eligible retrofits. Applicants must undertake both a pre- and post-retrofit EnerGuide evaluation of their home to be eligible for the grant.

The Canada Greener Homes Loan program offers interest-free financing to help eligible homeowners complete some of the major retrofits recommended by their energy advisor.

Eligible Canada Greener Homes Grant Initiative retrofits include:

  • home insulation, with up to $5,000,
  • air sealing, with up to $1,000,
  • windows and doors, with up to $5,000,
  • space and water heating upgrades, with up to $5,000,
  • solar photovoltaic renewable energy system, with up to $5,000, and
  • resiliency measures that protect the home and your family from environmental damages, up to $2,625.

The CleanBC Better Homes ad Homes Renovation Rebate Program, administered by BC Hydro, FortisBC and the Province of BC, provides rebates, bonus offers and specifies requirements that apply to a rebate application made based on the invoice date for each upgrade. You can use their use their Rebate Search Tool to find offers in your area.

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