Q3 2021 MD&A

MANAGEMENT'S DISCUSSION AND ANALYSIS

2021 Q3

FORWARD-LOOKING STATEMENTS

Certain statements in this MD&A are "forward-looking statements" within the meaning of applicable securities laws. These statements reflect Management's expectations regarding the REIT's future growth, results of operations, performance and business prospects and opportunities including expectations for the current financial year, and include, but are not limited to, statements with respect to Management's beliefs, plans, estimates and intentions, and similar statements concerning anticipated future events, results, circumstances, performance or expectations that are not historical facts. Statements that contain the words such as "could", "should", "would", "can", "anticipate", "expect", "does not expect", "believe", "plan", "budget", "schedule", "estimate", "intend", "project", "will", "may", "might", "continue" and similar expressions or statements relating to matters that are not historical factors constitute forward- looking statements. Such forward-looking statements reflect Management's current beliefs and are based on information currently available to Management.

These statements are not guarantees of future events or performance and, by their nature, are based on the REIT's current estimates and assumptions, which are subject to significant risks and uncertainties. A number of factors could cause actual results to differ materially from the results discussed in the forward- looking statements including, but not limited to, risks associated with real property ownership, debt financing, interest and financing, capital requirements, credit risk, general uninsured losses, developments, future property acquisitions, competition for real property investments, environmental matters, land leases, potential conflicts of interest, governmental regulations, the relative illiquidity of real property, taxation, reliance on key personnel, and the pandemic caused by the spread of the novel coronavirus ("COVID-19"). These risks, and others, are more fully discussed under Appendix F | Risks and Uncertainties in this MD&A. Material factors and assumptions that were applied in drawing a conclusion or making an estimate set out in the forward-looking information may include, but are not limited to: interest rates; access to equity and debt capital markets to fund, at acceptable costs, the future growth of the REIT and to enable it to refinance debts as they mature; the REIT's ability to maintain occupancy and to lease or re-lease space at current or anticipated rents; and the availability of purchase opportunities for growth in Canada. Given the impact of the COVID-19 pandemic, and government measures to contain it, there is inherently more uncertainty associated with any assumptions made. The REIT has attempted to identify important factors that could cause actual results, performance or achievements to be other than as expected or estimated and that could cause actual results, performance or achievements to differ materially from current expectations. These factors are not intended to represent a complete list of the factors that could affect the REIT. Although the forward-looking statements contained in this MD&A are based upon what Management believes to be reasonable assumptions, the REIT cannot assure investors that actual results will be consistent with these forward-looking statements.

The forward-looking statements contained herein are expressly qualified in their entirety by this cautionary statement and readers should not place undue reliance on such forward-looking statements. In addition, certain statements included in this MD&A may be considered a "financial outlook" for purposes of applicable securities laws, and such financial outlook may not be appropriate for purposes other than in this MD&A. These forward-looking statements are made as at the date of this MD&A and the REIT assumes no obligation to update or revise them to reflect new events or circumstances unless otherwise required to do so by applicable securities legislation.

NON-GAAPFINANCIAL MEASURES*

Readers are cautioned that certain terms used in this MD&A are non-GAAP financial measures that do not have any standardized meaning prescribed under IFRS and, therefore, should not be construed as alternatives to net income or cash flow from operating activities calculated in accordance with IFRS. Such terms do not have a standardized meaning prescribed by IFRS and the computation of these non-GAAP financial measures may not be comparable to similarly titled measures presented by other publicly traded entities. See Appendix A | Non-GAAP Financial Measures for more information on the non-GAAP financial measures used in this MD&A and their associated reconciliations. Non-GAAP financial measures are referenced with an asterisk footnote "*" throughout this MD&A.

The REIT's significant accounting policies are described in Note 3 to the audited consolidated financial statements for the years ended December 31, 2020 and 2019, and in Note 4 to the Financial Statements. The preparation of financial statements requires the REIT to make estimates and judgements that affect the reported results. For a detailed discussion of the critical estimates refer to Note 5 to the audited consolidated financial statements for the years ended December 31, 2020 and 2019, and to Note 3 to the Financial Statements.

Additional information relating to the REIT, including the latest AIF is filed on SEDAR and can be accessed electronically at www.sedar.com.

This Management's Discussion and Analysis of results of operations and financial condition of Summit Industrial Income REIT relates to the three and nine months ended September 30, 2021, and was approved by the Board of Trustees, upon the recommendation of its Audit Committee on November 8, 2021.

This MD&A has been prepared with an effective date of November 8, 2021, only includes material information and should be read in conjunction with the Financial Statements.

Financial data provided has been derived from financial statements that have been prepared in accordance with IFRS, which is the REIT's GAAP, with the exception of certain non-GAAP financial measures that are identified as such in this MD&A (see Appendix A |Non-GAAP Financial Measures).

Certain investment properties were classified as held for sale in periods reported within this MD&A. These investment properties were excluded from certain operational measures for the periods during which they were classified as held for sale, including property count, GLA, occupancy, and same property NOI. The number of properties and associated GLA of investment properties held for sale is reported by quarter in Appendix B | Summary Financial Results.

Except for per unit amounts and where otherwise noted, all amounts in this MD&A are reported in thousands of Canadian dollars. Except where indicated, GLA and sq. ft. are reported in thousands of sq. ft.

CONTENTS

1	| BUSINESS OBJECTIVES AND STRATEGY..........................................	10
2	| STRATEGIC VALUE DRIVERS ..........................................................	11
3	| FINANCIAL AND OPERATING HIGHLIGHTS.....................................	12
4	| KEY PERFORMANCE INDICATORS..................................................	14
5	| RESULTS OF OPERATIONS .............................................................	15
6	| PROPERTY PORTFOLIO..................................................................	18
7	| DEVELOPMENT AND EXPANSION ..................................................	21
8	| OPERATIONS.................................................................................	25
9	| LIQUIDITY AND CAPITAL ...............................................................	30
10 | DISTRIBUTIONS...........................................................................	37
11 | MARKET OVERVIEW AND OUTLOOK ...........................................	39
APPENDIX A | NON-GAAP FINANCIAL MEASURES ..............................	42
APPENDIX B | SUMMARY FINANCIAL RESULTS...................................	47
APPENDIX C | BALANCE SHEET ANALYSIS ...........................................	48
APPENDIX D | RELATED PARTY TRANSACTIONS .................................	49
APPENDIX E | TAXATION ....................................................................	51
APPENDIX F | RISKS AND UNCERTAINTIES..........................................	52
APPENDIX G | OTHER DISCLOSURES...................................................	62
APPENDIX H | GLOSSARY OF TERMS ..................................................	63

Founded in 2012, Summit is the only publicly-tradedpure-play industrial REIT with 100% of its properties located in Canada. Summit owns, manages and develops light industrial properties located in key major urban markets.

Summit is headquartered in Markham, Ontario and has 5 property management offices.

The light industrial sector is a vital part of the Canadian economy and is a stable long term asset class with numerous opportunities for growth. Summit's portfolio encompasses distribution facilities, warehouses,

cold storage and light manufacturing, with a focus on single-tenant larger properties.

Q3 2021 SNAPSHOT

Summit is listed on the TSX under the symbol SMU.UN and is a constituent of the S&P/TSX Capped REIT Index.

Number of Properties: 154

(20.1 million sq. ft)

Total Assets: $4.4 billion

99.2%

OCCUPANCY

29.3%

LEVERAGE*

$40.2 million

NET RENTAL INCOME

$0.086

FFO PER UNIT*

($0.180 EXCL.

PREPAYMENT COSTS)

71.5%

UNSECURED DEBT %

$253.0 million

NET INCOME

+5.4%

SAME PROPERTY NOI

GROWTH*

$2.8 billion

UNENCUMBERED

ASSETS

8.4x

DEBT-TO-ADJUSTED

EBITDA*

SUMMIT'S PORTFOLIO

ATTRACTIVE LIGHT INDUSTRIAL ASSET CLASS

						LOW CAPITAL
LOW RENT				GENERIC AND		MAINTENANCE,
VOLATILITY WITH		REDUCED			LEASEHOLD
		HIGHLY
HIGH TENANT		OPERATING COSTS			IMPROVEMENT &
		MARKETABLE SPACE
RETENTION					TENANT
						INDUCEMENT COSTS

Historically, vacancy rates in the industrial sector over the long term have been low, with a tenant base that is generally a reflection of the broader economy and increasingly includes e-commerce and logistics tenants. Property location, access to major highway infrastructure, as well as strong labour pools are key value drivers for industrial real estate.

REIT PORTFOLIO

The REIT's portfolio focuses on well-maintained larger properties in key target markets in Canada, encompassing distribution facilities, warehouses, light manufacturing and cold-storage. The majority of the REIT's properties encompass "Triple-Net" lease structures.

2300 Émile Bélanger Steet & 3665 Poirier Boulevard, Montreal QC

305 C H Meier Boulevard, Stratford, ON