Energy Savings by Retrofitting Multi-Unit Residential Buildings: Case Studies

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1 Energy Savings by Retrofitting Multi-Unit Residential Buildings: Case Studies Marianne Touchie, Kim Pressnail & Ekaterina Tzekova University of Toronto BEST 3, Atlanta, Georgia April 3 rd, 2012

2 Outline Energy use in MURBs Study Methodology Assumptions Case Studies: Rental Properties Condominium Properties Conclusions and Lessons Learned 2

3 MURBs in Toronto, Canada MURB Housing starts in the Toronto Area 28,200 Housing Stock 30% 15,900 Residential GHG Emissions % 3 30 year design life Figure Adapted from T. Kesik and I. Saleff Tower renewal guidelines. University of Toronto.

4 Methodology Building Owner/Manager Interviews Pre and Post-Retrofit Energy Consumption Analysis Weather normalization Energy Cost Savings Financial Performance of Retrofit Measures 4

5 Historical Utility Costs 5 Cost of Electricity/kWh and Natural Gas/m 3 $0.50 $0.40 $0.30 $0.20 $0.10 $ $2.50 $2.00 $1.50 $1.00 $0.50 Sources for Figure: City of Toronto E Ontario Energy Board Ontario Energy Board $- Cost of Water and Wastewater/m 3 Electricity Natural Gas Water

6 Projected Utility Costs $30 Average Utility Cost per m 2 $25 $20 $15 Electricity $10 Natural Gas $5 Water $

7 Case Study 1 (Rental) Pre-Retrofit Condition: 32 suites Built in 1930 s High maintenance costs Frequent equipment breakdowns 7 7

8 Case Study 1 (Rental) Retrofit Strategy: Windows Attic insulation Boiler controls and steam traps Common area lighting Faucets, showers, toilets 8 8

9 Case Study 1 (Rental) 60,000 40% 50% 4,000 Actual Performance Total Project Cost $74,200 Natural Gas Use (m 3 ) 45,000 30,000 15,000 3,000 2,000 1,000 Water Use (m 3 ) Tonnes CO 2 e avoided/annum Simple Payback 46 IRR over 10 years 10% Net Present Value (4% Discount Rate) 6.5 years $27,

10 Case Study 2 (Rental) Pre-Retrofit Condition: 128 suites Built in 1970 Roof reaching end of life Original, single-glazed windows 10 10

11 Case Study 2 (Rental) Retrofit Strategy: Improved building envelope (replace windows, balcony doors and roof) Reduced reliance on fossil fuels (install a solar thermal hot water system) 11 11

12 Case Study 2 (Rental) Annual Natural Gas Use (m 3 ) 500,000 21% 400, , , , * Projected Natural Gas Actual Natural Gas Actual Performance Total Project Cost (after incentives) Tonnes CO 2 e avoided/annum Payback based on energy cost savings Payback based on energy cost savings and increased rental income $568, years 3 years 12 12

13 Case Study 3 (Condominium) Pre-Retrofit Condition: 210 suites Built in 1974 Excessive energy bills Wanted to avoid borrowing costs 13 13

14 Case Study 3 (Condominium) Retrofit Strategy: Boiler Replacement Air Handling Unit (AHU) Retrofit Toilet Replacement Chiller Replacement 14 14

15 Case Study 3 (Condominium) 600,000 28% 29% 90,000 Actual Performance Natural Gas Use (m 3 ) 400, ,000 60,000 30,000 Water Use (m3) Total Project Cost $678,000 Tonnes CO 2 e avoided/annum Simple Payback years Net Present Value $267,

16 Case Study 4 (Condominium) Pre-Retrofit Condition: 116 suite Occupied in 2001 Investigation into solar energy led to discovery of other energy savings measures 16 16

17 Case Study 4 (Condominium) Retrofit Strategy: Lighting Retrofit CO Monitor Installation Boiler Replacement Installation of Variable Frequency Drive on Make- Up Air Unit 17 17

18 Case Study 4 (Condominium) 400,000 31% 12% 1,600,000 Actual Performance Natural Gas Use (m 3 ) 300, , ,000 1,200, , ,000 Electricity Use (kwh) Total Project Cost (after incentives) Tonnes CO 2 e avoided/annum Simple Payback $146, IRR over 10 years 45% 2.4 years Net Present Value $260,

19 Summary of Retrofit Impacts Cost of Avoided GHG Emissions ($/tco 2 e) 19 $1,200 $1,000 $800 $600 $400 $200 $83/tCO 2 $- Lighting/ Exhaust /MAU (Bldg 4) Toilet Replacement (Bldg 3) Lighting Retrofit (Bldg 1) Water Fixture Replacement (Bldg 1) Boiler Replacement (Bldg 4) Chiller upgrade (Bldg 3) Boiler Replacement (Bldg 3) Boiler Controls/Wndw Replace/Attic insulation (Bldg 1) Simple Payback (yrs)

20 Lessons Learned Planning: Whole Building Approach Establish Baseline Utility Use Enhance Existing Maintenance Projects Quick Payback + Longer Payback Items 20 20

21 Lessons Learned Financing: Energy Conservation Incentives Financial Analysis Tools Construction: COMMUNICATION! Operations: Ongoing control 21 hwww.mediatonet.com/financing.html, ableandbakerdesign.blogspot.com/2009/09/1968-airstream-retrofit-window.html 21

22 For more information Energy Retrofit Case Studies on the TowerWise Website towerwise.ca/case_studies Marianne Touchie 22 22