You will be directly admitted to the Bachelor's programme if you possess a Dutch vwo diploma with a profile in Natuur & Techniek (nature and technology). If you have done another profile, you have to have Wiskunde B (advanced mathematics) and Physics in your profile in order to be able to enter the programme. Read more about the admission requirements and how you can sign up.
Mathematics is an indispensable part of all science programmes. Experience shows that if you are good at exact sciences (Mathematics, Physics, Chemistry), you will have a greater chance of success in studying Civil Engineering then if you have difficulty with them. If you feel that you need to work on these areas, you can do an extra mathematics course at the beginning of the summer holidays.