1. Results third quarter and first nine months 2005 Harrie Noy, CEO ARCADIS NV November 9, 2005

2. Excellent third quarter Net income +36%; net income from operations +46% Gross revenue growth 7%, of which 5% organically Strong growth in U.S. environment and in Brazil Strong margin improvement: 8.0% versus 5.7% last year Acquisitions/divestments also contribute to profit improvement Profit outlook for 2005 increased to 30 – 35% Strategy to improve margins is paying off

3. Net income third quarter 2005: € 6.3 million Gross revenue Ebita Net income Net income per share 1) Net income from operations 2) Ditto per share 1,2) 1)2005 based on 20.3 million shares outstanding (2004: 20.1 million) 2)Excluding amortization, pension adjustments and non-recurring items consisting of book profits and reorganization charges in 2004 and book profits in 2005 2005 236 13.0 6.3 0.31 7.5 0.37 2004 221 5.6 4.6 0.23 5.1 0.25  7% 133% 36% 46%

4. Net income 9 months 2005: € 20.8 million Gross revenue Ebita Net income Net income per share 1) Net income from operations 2) Ditto per share 1,2) 1)2005 based on 20.3 million shares outstanding (2004: 20.1 million) 2)Excluding amortization, pension adjustments and non-recurring items consisting of book profits and reorganization charges in 2004 and book profits in 2005 2005 692 38.5 20.8 1.03 20.8 1.02 2004 652 22.8 14.8 0.74 15.8 0.79  6% 68% 41% 40% 31% 30%

5. Increased focus in portfolio Divestments Detailed engineering buildings, U.S. 50% interest in Grupo EP, Spain Renardet/Sauti in donor-funded market Book profit in Q2: € 2.1 million (net) Acquisitions SWK, Belgium; infrastructure AYH, U.K.; project management Greystone, U.S.; environment Blasland, Bouck & Lee, U.S.; environment Per April 1 Mid-June End of June Mid-May Mid-June End of June End of September Positive impact on margins

6. Major acquisition in the U.S.: Blasland, Bouck & Lee Gross revenue $170, net revenue $110 Superior margins Leading environmental services provider 80% of revenues from industrial clients Combined top 5 world player in environment Leader in environmental services for industry Many opportunities for synergies - Services to BBL multinational clients globally - GRiP® approach for BBL clients - Client based business model as basis for integration Industrial consultancy Life sciences Sediment remediation

7. Organic growth continues at good level Currency -2% -3% -3% -3% 0% Selling prices - +2% +0% +1% -1%

8. Gradual recovery Dutch market Slight decline in gross revenues in Q3, but Profitability continues to improve due to restructuring in 04 Backlog improved by >25% compared to year end 04 More work on upgrading rail infrastructure Municipal market is picking up More PPS/PFI initiatives Facility management contract signed with DSM & Sabic Dutch operations back on track

9. Impact of non recurring items on Ebita Ebita Reported Non recurring Recurring 2005 13.0 - 13.0 2004 5.6 -/-3.1 8.7 Q3 2005 38.5 2.1 36.4 2004 22.8 -/-4.5 27.3 Q3 YTD Non recurring items 2004: book profits and restructuring charges Non recurring items 2005: book profits

10. Growth in Ebita first nine months 2005 Ebita Currencies +1% Acquisitions/divestments +13% Organic +19% Growth achieved +33% Non-recurring + 68% Reported + 33% On recurring basis Strong margin improvement from 5.8% to 7.4%

11. Gross revenue market segments Q3 YTD 2005

12. Infrastructure +8% (+3%) Acquisitions contributed 4% (U.S., Poland, Belgium) Strong growth in Brazil for both private and public sector Growth in U.S. driven by land development European market good in Poland, France, Belgium Dutch market recovers; contract for prestigious Zuid-as A’dam

13. Environment +11% (+11%) Continued strong growth in U.S. GRiP® and traditional work Contribution from acquisitions 2%, off set by currency impact Acquisition of BBL major strategic step forward In Poland, Brazil and Chile growth from private sector clients Belgium and Germany also demonstrate growth

14. Facilities +5% (+6%) Acquisition AYH makes up for earlier divestments Revenue decline in Q3 lower organic growth Q3 YTD Less revenue in Q3 caused by shifts in subcontracting Net revenue increased >10% organically in Q3 Facility management contract signed with DSM and Sabic

15. Geographic distribution of gross revenue 20042005

16. Outlook full year 2005 Most markets are favorable European market solid particularly CentralEurope U.S. and Brazilian market strong Dutch market gradually recovering Most units perform well

17. Outlook per market segment Infrastructure SAFETEA to drive U.S. growth In Europe France and Poland good prospects Dutch market recovery expected to continue Environment U.S. strong backlog basis for continued growth BBL client base offers international leverage Facilities AYH good basis for worldwide project consulting Project and facility management well established

18. Profit outlook 2005 increased ARCADIS well positioned in growing markets Synergy contributes to growth Focus on margin improvement continues Synergy and integration BBL have high priority Net income from operations 30 to 35% higher (barring unforeseen circumstances) ARCADIS is well on track

19. Thank you