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

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 H 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

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) _  _ 26% 27% 47% 18% 60% Income second quarter 2006: € 11.8 million

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) _  _ 27% 39% 51% 35% 60% Income first half 2006: € 21.2 million

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

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%

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

Net income from operations and EPS H-1 Earnings per share (in €) *) Adjusted for IFRS +13%+8%-/-10% In € millions %+24% %

The service areas Infrastructure Environment Facilities

Organic growth in all service areas

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

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

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

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

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

Unlocking the hidden value of ARCADIS

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

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 € In

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

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

Our margin improved considerably Excluding non-recurring items Target

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

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 Our balance sheet remains strong Ample room for further investments target

Geographic distribution has changed

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

We unlocked some hidden value Stock outperformed market and all peers

Liquidity increased, In € million Number of shares In millions of shares 12 (6 months) broader shareholder base

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

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

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

Outlook

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

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

Thank you