1. Results first half 2006 Harrie Noy, CEO Analyst meeting, August 9, 2006, Antwerp, Belgium Infrastructure, environment, facilities

2. Strong results first half 2006 Gross revenue 27% higher, 8% organic increase Strong organic growth in all market segments Margin improves considerably: 8.6% versus 7.0% in H1-2005 Net income from operations increased 60% Over $80 million in new GRiP® contracts Integration BBL is progressing well Strategy to enhance growth is yielding results

3. Gross revenue Ebita Ebita recurring Net income Net income per share 2) Net income from operations 1) Ditto per share 1,2) 1) Before amortization and non-operational items 2) In 2006 based on 20.2 million shares outstanding (2005: 20.3 million) 2006 293 19.2 10.6 0.52 11.8 0.58 2005 233 15.0 13.0 9.0 0.44 7.4 0.36 _  _ 26% 27% 47% 18% 60% Income second quarter 2006: € 11.8 million

4. Gross revenue Ebita Ebita recurring Net income Net income per share 2) Net income from operations 1) Ditto per share 1,2) 1) Before amortization and non-operational items 2) In 2006 based on 20.2 million shares outstanding (2005: 20.3 million) 2006 581 35.3 19.6 0.97 21.2 1.05 2005 457 25.4 23.4 14.5 0.71 13.3 0.65 _  _ 27% 39% 51% 35% 60% Income first half 2006: € 21.2 million

5. Dutch market recovery better than expected After years of decline, organic growth of 9% Facility management contract DSM/Sabic contributes to growth Also growth in infrastructure: 6% organic A lot of investment in rail infrastructure renewal/maintenance More PPP initiatives – Zuidas, Coentunnel, Kazerne Utrecht More outsourcing Ministery Public Works – broadening A50, A12, A28 A lot of demand for project management and cost consultancy Acquisition In Situ Technieken strengthens environmental position

6. Development Ebita first half In € millions 13% 11% -/-27%15% 48% *) Adjusted for IFRS Increase 6.3% 7.2% 5.2% 5.9% 7.0% Margin 10% 5% 0% 8.6% 39%

7. Recurring EBITA grows considerably (51%) In € million 34% 4% 13% 25.4 35.3 23.4 Organic increase mainly from U.S., Brazil and Netherlands

8. Net income from operations and EPS H-1 Earnings per share (in €) *) Adjusted for IFRS +13%+8%-/-10% In € millions 0.49 0.52 0.47 0.53 0.65 +12%+24% 1.05 +60%

9. The service areas Infrastructure Environment Facilities

10. Organic growth in all service areas

11. Revenue decline caused by last year’s divestments Continued very strong growth in Brazil: mining and energy Strong growth in U.S., especially transportation and tunnels Market recovery Netherlands, healthy growth in France High backlog in Poland; procedures impact revenues PPP initiatives yield work Infrastructure -/-2% (+6%) Rouen: award winning bridge design

12. Revenue doubled, mainly through acquisition BBL & Greystone Strong organic growth in U.S.: GRiP® and corporate consulting Backlog GRiP® to $ 300 million at end of Q2 U.K. and Netherlands strongest growth in Europe European environmental team for extra growth In Brazil and Chile large demand for mining consultancy Environment +96% (+10%) Sediment remediation by BBL

13. Acquisition AYH (mid 2005) strong contributor to growth Arsenal stadium (project management AYH) in U.K. completed Facility management DSM/Sabic drives Dutch growth Good investment climate in Belgium, France, Brazil Reduction poorly performing detailed engineering Germany Facilities +29% (+12%) DSM contract yields growth in FM

14. In 2000 we revised our strategy International expansion in the nineties had been successful But ARCADIS’ performance and stock price were lagging behind

15. Strategy focused on value creation Increase organic growth in existing core business Synergy based on specialized expertise & client relationships Improve margins Reducing or outsourcing low margin business Focusing on services with higher added value Speed up strategy by acquisitions Focus on strengthening home market positions Goal was more focus and higher earnings growth

16. Unlocking the hidden value of ARCADIS

17. Focus on 3 market segments 2000 revenues € 800 mln 2006 revenues € 1,200 mln

18. Strong shift in our portfolio Acquisitions Expansion Europe Infra US Environment US Management services Home market positions Total Divestments Non core business NL Facilities Spain Donor funded market Total FCI (France), Profil (Poland) RMA, FPS, LNW, BHR, Diversity Greystone, BBL Homola, PRC, AYH, CDG Belgium, Brazil, Netherlands, UK Part of contracting, Kafi/Mandaat Detailed engineering (US) 50% interest in Grupo EP Renardet/Sauti (France) GR in € 82 74 154 80 24 414 53 15 68 11 147 In 05 154 36 6 196 15 68 11 94

19. Currency -4% -2% -3% -3% -3% +1% +3% Divestments +1% - +2% +0% +1% -0% - Organic growth increased Target organic growth Target total growth

20. In facilities we shifted to management services Project & program management and facility management We want to focus on higher added value services Divestment detailed engineering US Acquisition of management services Homola, PRC, AYH, CDG Also facility management Joint venture with Aqumen Focus on NL/Europe Two major contracts for 4 years AYH New Arsenal stadium, London

21. Our margin improved considerably Excluding non-recurring items 2003 2004 2005 Target

22. We generated € 266 million cash in 5 years, also by reducing working capital In € million

23. 1,2 3 excluding non-recurring effects 1 basis: average quarterly balance sheets; dividend separated at moment of payment 2 basis: net interest bearing debt 3 2003 20042005 Our balance sheet remains strong Ample room for further investments target

24. Geographic distribution has changed 2000 2006

25. We sharpened our positioning Less project focus, more client focus Less technical, more value creation Pro-active, agile and result driven Innovative and creative More business oriented and higher in the value chain: Imagine the result

26. We unlocked some hidden value Stock outperformed market and all peers

27. Liquidity increased, In € million 2 6 8 10 4 Number of shares In millions of shares 12 (6 months) 2000 2006 broader shareholder base

28. We are well positioned ! Global trends favorable to ARCADIS Present market conditions solid Strategy implies choices for growth Ambitious goals for market segments

29. Strategy: three international growth platforms Infrastructure growth target 4 – 6% Expand strong local positions Additional growth in rail infrastructure and bridges/tunnels Environment growth target 8 – 12% Expand remediation services to be global leader Leverage relationships with multinational clients Add front-end consultancy services Facilities growth target 5 – 10% Become benchmark world-wide project management firm Expansion in facility management

30. We continue with acquisitions At a somewhat lower pace in 2006 Integration BBL has first priority Strengthening home market positions U.S., Europe and Brazil Strengthening Growth Platforms Rail, tunnels/bridges, remediation, project management Geographical expansion Asia Europe: Rumania, Northern Italy Look for larger opportunities

31. Outlook

32. Outlook per service area Infrastructure Growing economy drives Dutch market recovery In Europe more private investment through PPP initiatives U.S.: SAFETEA and New Orleans; investment Brazil high Environment GRiP® offers room for further growth in the U.S. Synergy with BBL offers opportunities with multinationals In Europe and Latin America increase services to industry Facilities Facility management benefits from outsourcing trend Aim at position with international real estate investors

33. Outlook for full year 2006 positive ARCADIS is well positioned in markets that offer opportunity Synergy contributes to growth Continued focus on higher value added activities Integration BBL (client focussed business model) priority for 2006 Integration BBL and SOX 404: € 3 to 4 million out of pocket costs Acquisition policy continued, but at a lower pace Expected increase net income from operations by 30% to 35% (barring unforeseen circumstances) ARCADIS is well on track

34. Thank you