Westridge Duplex

A southeast BC duplex wanting to improve ventilation to fix mould and indoor air quality issues, replace propane with electrical, add a heat pump, and upgrade attic insulation while replacing all windows and doors.

Building Type Single-Family Bungalow (incl. 1.5 Story) Location Invermere, BC
Year Built 1999 Foundation Type Concrete (Full Basement)
Structure Type Wood-Framed Post-Retrofit Total Floor Area 214.1m2
Climate Zone 6 Heating Degree Days 4650
Retrofit Status Complete Year Completed 2025
Retrofit Phasing Yes Geometry Changed No
Annual Energy Savings 34.76% Operational Carbon Savings 1.65 tCO2eq/y
Retrofit Type Envelope and Mechanical Performance Level The focus for this home was energy reductions, comfort, and HEALTH as this family has respiratory illnesses and are loving the fresh clean indoor air quality.

Project Team

Retrofit Support Organization

Organization Name: Community Energy Association

Program Name: Retrofit Assist

Website: Retrofit Assist

Project Priorities

  • Reduce Energy Consumption
  • Increase Thermal Comfort
  • Improve Indoor Air Quality
  • Reduce GHG Emissions

Project Goals

LEEP10 project is part of the Retrofit Assist program, but is a distinctly separate program trialling a General Contractor model with a sub-contracting trade team, using Integrated Design Process to create 2-phase Deep Energy Retrofit Plans. DER plans provide homeowners with an accessible starting point, including a roadmap to net zero.

The Client

Client is interested in retrofitting their home to improve comfort, energy efficiency, and reduce energy bills. Duplex home with 7 occupants (2 adults and 5 children) living in the home. There is an undersized HRV in the basement. There is a 100amp service and there is concern with the high moisture level in the home.

Key Goals: (goals that must be met, or the project will not move forward)

  1. Budget – The project must stick to client budget (<$100K)
  2. Ventilation – this is high priority with mould and IAQ issues in some areas of the home
  3. DHW – Replace propane tank with electric system
  4. Heating/Cooling – upgrade with Heat Pump – mini split system
  5. Insulation – Upgrade attic insulation
  6. Windows – Replace all 9 windows and 2 doors

Secondary goals: (goals that can have some flexibility, could be described as preferences rather than must haves)

  1. Carbon Reductions – Mechanical system upgrades have largely accomplished this already.
  2. Resiliency – explore solar generation and battery backup in future
  3. Long term improvements and energy bill reduction – lower bills as home improves over time.

Upgrades

Envelope Improvements

  • Wall Insulation – Exterior – Foam Board Insulation
  • Attic / Roof Internal Insulation
  • Foundation Walls Exterior Insulation

Windows and Door Improvements

  • Window Replacement – Triple Pane
  • Door Replacement – High Performance

Mechanical: Heating and Cooling Improvements

  • Air Source Heat Pump – Mini-Split

Mechanical: Ventilation Improvements

  • Heat Recovery Ventilator (HRV)
  • Kitchen / Bathroom Ventilation

Mechanical: Hot Water Improvements

  • Electric Hot Water Tank

Health, Safety & Sustainability Improvements

  • MERV 13 or Above Air Filtration
  • Low-Embodied Carbon Materials

Project Description

Getting to Net Zero

DESIGN 43% energy savings projected as part of the Integrated Design Process (IDP)

OUTCOMES 35% energy savings and 69% GHG reduction! Indoor air quality (IAQ) is vastly improved. Temperature stability and comfort vastly improved. Homeowners and tenants are very happy with comfort, aesthetics, and health outcomes. Retrofit was relatively low cost, well under budget.

Total cost <$80,000 (+/- $1,900 GJ)

The focus for this home was energy reductions, comfort, and HEALTH as this family has respiratory illnesses – they are now loving the fresh, clean indoor air.

Before & After

General

Envelope

Mechanical & Electrical

Annual Energy Usage

Carbon Emissions

Technical Documents

Photos