Energy Savings by Retrofitting Multi-Unit Residential Buildings:

Case Studies

Marianne Touchie, Kim Pressnail & Ekaterina Tzekova University of Toronto

BEST 3, Atlanta, Georgia April 3rd, 2012

• Energy use in MURBs • Study Methodology • Assumptions • Case Studies: • Conclusions and Lessons Learned

Outline

2

Rental Properties Condominium Properties

MURBs in Toronto, Canada

3

MURB Housing starts in the Toronto Area

30 year design life

Housing Stock

Residential GHG Emissions

30%

40% 1950

1960

1970

1980

1990

2000

28,200

15,900

Figure Adapted from T. Kesik and I. Saleff. 2009. Tower renewal guidelines. University of Toronto.

Methodology

4

• Building Owner/Manager Interviews

• Pre and Post-Retrofit Energy Consumption Analysis

• Weather normalization

• Energy Cost Savings

• Financial Performance of Retrofit Measures

$-

$0.50

$1.00

$1.50

$2.00

$2.50

$0.00

$0.10

$0.20

$0.30

$0.40

$0.50

2003

2004

2005

2006

2007

2008

2009

2010

Historical Utility Costs

5

Cost

of W

ater

and

Was

tew

ater

/m3

Cost

of E

lect

ricity

/kW

h an

d N

atur

al G

as/m

3

Electricity

Natural Gas

Water Sources for Figure: City of Toronto. 2010. http://www.toronto.ca/utilitybill/water_rates.htm; E Ontario Energy Board 2010 http://www.ontarioenergyboard.ca/OEB/Consumers/Electricity/Electricity+Prices; Ontario Energy Board. 2010 http://www.oeb.gov.on.ca/OEB/Consumers/Natural+Gas/Natural+Gas+Rates/Natural+Gas+Rates+-+Historical;

Projected Utility Costs

6

$-

$5

$10

$15

$20

$25

$30

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

Aver

age

Util

ity C

ost p

er m

2

Electricity

Natural Gas

Water

Pre-Retrofit Condition:

32 suites Built in 1930’s High maintenance costs Frequent equipment breakdowns

Case Study 1 (Rental)

7 7

Retrofit Strategy:

Windows

Attic insulation

Boiler controls and steam traps

Common area lighting

Faucets, showers, toilets

Case Study 1 (Rental)

8 8

Actual Performance

Total Project Cost $74,200

Tonnes CO2e avoided/annum 46

Simple Payback 6.5 years

IRR over 10 years 10%

Net Present Value (4% Discount Rate)

$27,000

Case Study 1 (Rental)

9 9

0

15,000

30,000

45,000

60,000

Nat

ural

Gas

Use

(m3 )

0

1,000

2,000

3,000

4,000

Wat

er U

se (m

3 )

50% 40%

Pre-Retrofit Condition:

128 suites Built in 1970 Roof reaching end of life Original, single-glazed windows

Case Study 2 (Rental)

10 10

Retrofit Strategy:

Improved building envelope (replace windows, balcony doors and roof)

Reduced reliance on fossil fuels (install a solar thermal hot water system)

Case Study 2 (Rental)

11 11

Case Study 2 (Rental)

12 12

0

100,000

200,000

300,000

400,000

500,000

2007 2008 2009 2010 2011*

Annu

al N

atur

al G

as U

se (m

3 )

Projected Natural Gas Actual Natural Gas

21%

Actual Performance Total Project Cost (after incentives) $568,000

Tonnes CO2e avoided/annum 160

Payback based on energy cost savings 16 years

Payback based on energy cost savings and increased rental income

3 years

Pre-Retrofit Condition:

210 suites Built in 1974 Excessive energy bills Wanted to avoid borrowing costs

Case Study 3 (Condominium)

13 13

Retrofit Strategy:

Boiler Replacement Air Handling Unit (AHU) Retrofit Toilet Replacement Chiller Replacement

Case Study 3 (Condominium)

14 14

Actual Performance

Total Project Cost $678,000

Tonnes CO2e avoided/annum 277

Simple Payback 4 years

Net Present Value $267,000

Case Study 3 (Condominium)

15 15

0

200,000

400,000

600,000

Nat

ural

Gas

Use

(m3 )

28%

0

30,000

60,000

90,000

Wat

er U

se (m

3)

29%

Pre-Retrofit Condition:

116 suite Occupied in 2001 Investigation into solar energy led to discovery of other energy savings measures

Case Study 4 (Condominium)

16 16

Retrofit Strategy: Lighting Retrofit CO Monitor Installation Boiler Replacement Installation of Variable Frequency Drive on Make-Up Air Unit

Case Study 4 (Condominium)

17 17

Case Study 4 (Condominium)

18 18

Actual Performance Total Project Cost (after incentives) $146,000

Tonnes CO2e avoided/annum 153

Simple Payback 2.4 years

IRR over 10 years 45%

Net Present Value $260,000

-

400,000

800,000

1,200,000

1,600,000

Elec

tric

ity U

se (k

Wh)

12%

-

100,000

200,000

300,000

400,000

Nat

ural

Gas

Use

(m3 )

31%

19

$83/tCO2

Summary of Retrofit Impacts

Boiler Controls/Wndw Replace/Attic

insulation (Bldg 1) Boiler Replacement

(Bldg 3)

Boiler Replacement (Bldg 4)

Lighting Retrofit (Bldg 1)

Lighting/ Exhaust /MAU

(Bldg 4)

Water Fixture Replacement (Bldg 1)

Toilet Replacement (Bldg 3)

Chiller upgrade (Bldg 3)

$-

$200

$400

$600

$800

$1,000

$1,200

0 2 4 6 8 10

Cost

of A

void

ed G

HG E

miss

ions

($/t

CO2 e

)

Simple Payback (yrs)

Planning:

Whole Building Approach Establish Baseline Utility Use Enhance Existing Maintenance Projects Quick Payback + Longer Payback Items http://www.stlucieco.gov/planning/planning.htm

Lessons Learned

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Financing:

Energy Conservation Incentives

Financial Analysis Tools Construction:

COMMUNICATION! Operations:

Ongoing control

hwww.mediatonet.com/Financing.html, www.reggin.ca/hvac.htm, www.afmcontrols.com/, ableandbakerdesign.blogspot.com/2009/09/1968-airstream-retrofit-window.html

Lessons Learned

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For more information…

Energy Retrofit Case Studies on the TowerWise Website towerwise.ca/case_studies

Marianne Touchie

marianne.touchie@utoronto.ca

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