Q3 2018 results November 8, 2018

Forward-Looking Statements and Non-IFRS Measures Certain information regarding WSP contained herein may constitute forward-looking statements. Forward-looking statements may include estimates, plans, expectations, opinions, forecasts, projections, guidance or other statements that are not statements of fact. Although WSP believes that the expectations reflected in such forward-looking statements are reasonable, it can give no assurance that such expectations will prove to have been correct. These statements are subject to certain risks and uncertainties and may be based on assumptions that could cause actual results to differ materially from those anticipated or implied in the forward-looking statements. WSP's forward-looking statements are expressly qualified in their entirety by this cautionary statement. The complete version of the cautionary note regarding forward-looking statements as well as a description of the relevant assumptions and risk factors likely to affect WSP's actual or projected results are included in the Management's Discussion and Analysis for the year ended December 31, 2017, which is available on SEDAR at www.sedar.com. The forward-looking statements contained in this presentation are made as of the date hereof and WSP does not assume any obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise unless expressly required by applicable securities laws. WSP reports its financial results in accordance IFRS. However, in this presentation, the following non-IFRS measures are used by WSP: net revenues, adjusted EBITDA, adjusted EBITDA margin, free cash flow, days sales outstanding (DSO) and EBITDA. These measures are defined at the end of the « Glossary section » of WSP’s MD&A dated November 7, 2018 and a reconciliation to IFRS measures can be found in the MD&A. Management of WSP believes that these non-IFRS measures provide useful information to investors regarding WSP’s financial condition and results of operations as they provide key metrics of its performance. These non-IFRS measures are not recognized under IFRS, do not have any standardized meaning prescribed under IFRS and may differ from similar computations as reported by other issuers, and accordingly may not be comparable. Organic growth is a measure of net revenues growth in local currencies. WSP believes it is helpful to adjust net revenues to exclude the impact of net revenues related to acquisitions and foreign currency fluctuations in order to facilitate comparable period operating segment business performance. All of the aforementioned measures should not be viewed as a substitute for the related financial information prepared in accordance with IFRS.

Q3 2018 Highlights

Q3 2018 Results Q3 2018 Highlights Solid Q3 18 financial results, with organic growth in net revenues and strong trailing twelve-month free cash flow Launch of the “WSP Global Cities Index” Significant strides in our 2019-2021 Strategic Plan that will be released at the end of January 3

Net revenues were $1.5 billion, up 14.2% Organic growth in net revenues was strong at 4.1% Adjusted EBITDA at $187.5 million Adjusted EBITDA at 12.7% Backlog, stood at $6.5 billion, representing approximately 9.8 months of revenues Backlog organic growth amounted to 2.7%

2018 WSP Global Cities Index Q3 2018 Results 2018 WSP Global Cities Index We turned our lens to the future and explored how cities are identifying and responding to the challenges they will face in the coming two decades, and beyond. Insights about how cities are preparing for a future of urban transitions

Financial Performance Q3 2018 Financial Performance

Q3 2018 Financial Highlights 4.1% organic growth in net revenues 12.7% Adjusted EBITDA margin 76 days end-of-period DSO $555.6 million trailing twelve- month free cash flow (236.3% of net earnings attributable to shareholders) 1.4 times net-debt-to-adjusted EBITDA ratio

Revenues and Net Revenues* +17.8% +14.2% 4.1% organic growth in net revenues REVENUES NET REVENUES Q3 2017 Q3 2018 * In millions CAD – Non-IFRS measures

Adjusted EBITDA* and Adjusted EBITDA margin +16.9% 12.5% margin 12.7% margin * In millions CAD – Non-IFRS measures

Adjusted Net Earnings* +24.9% $0.77/share $0.95/share * In millions CAD – Non-IFRS measures

Backlog* 9.8 months of revenues Q3 2018 Results Backlog* 9.8 months of revenues Q3 2018 COMPARED TO Q3 2017 and Q4 2017 (in millions of dollars, except percentages) Total Hard Backlog Q3 2018 $6,509.1 Hard Backlog Q3 2017 $5,963.9 Net change ($) $545.2 Organic growth compared to Q3 2017 2.7% Organic growth compared to Q4 2017 1.9% 13 * In millions CAD – Non-IFRS measures

Canada 1.2% Organic growth in net revenues Q3 2018 Results Canada 1.2% Organic growth in net revenues 15.9% Adjusted EBITDA margin before Global Corporate costs Contract with the Toronto Transit Commission for the Yonge Subway Extension project in Markham 5

Americas 3.7% organic growth in net revenues Q3 2018 Results Americas 3.7% organic growth in net revenues 18.1% adjusted EBITDA margin before Global Corporate costs Significant project extension in the state of California) 6

EMEIA 4.5% organic growth in net revenues Q3 2018 Results EMEIA 4.5% organic growth in net revenues 10.5% Adjusted EBITDA margin before Global Corporate costs Substantial multi-disciplinary scope of work contract on the new commercial landmark at 100 Leadenhall Street, which is slated to become the third tallest building in London 7

Q3 2018 Results APAC 7.8% organic growth in net revenues 14% Adjusted EBITDA margin before Global Corporate costs Key role in bringing the biggest investment in public school infrastructure in NSW to life 8

Stable DSO* *Non-IFRS measures

Financial position and net debt/TTM adjusted EBITDA* ratio (in $M, CAD) Q3 2018 Financial liabilities $1,078.3 Less: Cash ($173.9) Net debt $904.4 TTM adjusted EBITDA* $630.5 Net debt / TTM adjusted EBITDA* (adjusted for 12-month net revenues for all acquisitions) 1.4x * In millions CAD – Non-IFRS measures

2018 Outlook Reiterated Net revenues* Between $5,700 million and $5,900 million Adjusted EBITDA* Between $610 million and $660 million Seasonality and adjusted EBITDA* fluctuations Q1: 18% to 21% Q2: 25% to 28% Q3: 26% to 29% Q4: 24% to 27% Tax rate 23% to 25% DSO* 80 to 85 days Amortization of intangible assets related to acquisitions Between $60 and $70 million Capital expenditures Between $115 and $125 million Net debt to adjusted EBITDA* 1.5x to 2.0x1) Acquisition and reorganization costs* Between $40 million and $50 million 2) Net revenues and adjusted EBITDA expected to be in the higher end of ranges * Non-IFRS measure. 1) Target excluding any debt required to finance acquisitions 2) Due mainly to personnel and real estate integration costs related to the acquisition of Opus completed in Q4 2017, to real estate integration costs pertaining to the Mouchel acquisition completed in Q4 2016 and IT outsourcing program costs.