Case study

Duplex from 1959

Here’sa case study

based on energy efficiency analysis reports, before and after work, carried out by an expert firm commissioned by Transition Énergétique Québec.

The purpose of the work was to improve the energy efficiency of the above-ground exterior walls of a 2-unit detached duplex built in 1959. The work was subsidized under the Rénoclimat renovation assistance program. The insulation work was completed in just 8 hours.


Insulation work on a 1959 duplex

Setting the scene

  • The customer wanted to insulate his building to reduce heating costs and improve comfort for his tenants.
  • Inside walls with sufficient air space (0.75pc and =)
  • The interior of the wall structure is free, sound and without any apparent problems.


  • High insulation costs due to demolition.
  • Long lead times due to demolition, reconstruction and finishing work, which can take from 15 to 30 days.
  • Little space available for insulation.
  • Relocation of tenants, storage of goods.
  • Several tons of demolition and construction waste.


Building description

  • Customer/owner : B/W
  • Locations: Quebec City, QC
  • Housing type: 2-unit detached duplex
  • Number of floors: 2
  • Year of construction: 1959
  • Living area: 1050 p2
  • Heating system: electric
  • Number of windows and OBs: 13
  • No air-conditioning system
case study duplex 1959 insulation


Energy assessment BEFORE work

Reference: Evaluation report produced by an accredited consultant mandated by Transition Énergétique Québec.

Analysis report date: November 16, 2018

File reference # 3M03D18229

Analysis of test results used for building energy assessment prior to insulation work.

  • Insulating value of empty walls: R-0 @ R-14
  • Air infiltration rate: 4.23 CAH
  • Equivalent air leakage area: 745 cm2
  • Estimated heat loss: 86 gigajoules
  • Energy rating: 60
  • Main heat loss: walls
  • Heating energy consumption: 67%.

Recommendation increase wall insulation value by 1.6 RSI (R9) and lower air change rate per hour to 3.80 CAH


Energy assessment AFTER work

Reference: Evaluation report produced by an accredited consultant mandated by Transition Énergétique Québec.

Date of final analysis report: November 2018

Analysis of test results used to assess the building’s energy performance after insulation work.

  • Empty wall insulation value: R-15.82 @ R-18.29
  • Air infiltration rate: 3.61 CAH
  • Equivalent air leakage area: 637 cm2
  • Estimated heat loss: 41 gigajoules
  • Energy rating: 70
  • Heating energy consumption: 56%.
  • GHG reduction: 6.4 tonnes/year
energy loss analysis report
duplex heat loss


Summary of results after case study

  • Average insulation value of treated walls increased from (R-0 @ R-14) to (R-15.82 @ R-18.29)
  • Air infiltration rate dropped from 4.23 (CAH) to 3.61 (CAH), an approximate but significant decrease of 5208ft3 of air change/hr.
  • Air leakage area in the building envelope reduced from 745 cm2 to 637 cm2, equivalent to caulking a 111cm2 gaping hole (10cm x 10cm).
  • Significant improvement in heat loss, from 86 (GJ/year) to 41 (GJ/year) for a gain of 45 gigajoules/year.
microbeads insulation without demolition

Comparison table

Number of days planned for insulation work 15 – 30 days 1 day
Total cost of insulation work 30000$ – 40000$ 6000$
Renovation grant 2685 min. 2685 min.
Major constraint Rented accommodation
Amortization 10 – 20 years 5 to 10 years
Quantity of renovation waste 2500 kg 5 kg

We have identified several advantages of using microbead injection technology Ecobill MD/® microbead injection technology.


  • Work easily carried out in an occupied dwelling;
  • Quick response. Generally speaking, 1 day is enough for a 2400 sq. ft. bungalow;
  • No demolition required, clean;
  • No health hazards, harmful dust or vapors (asbestos).
  • Represents a fraction of the price of conventional work with demolition;
  • Short- and medium-term amortization of work;

Environmental impact

  • Enhancing the value of existing buildings;
  • A zero waste approach to renovation;
  • Reuse of 2.90 cubic meters of recycled polystyrene.
  • Easily recovered during deconstruction, does not contaminate materials in contact with it;
  • 100% recyclable for reuse in the same polystyrene microbead injection process.


Some photos of the work