Tosca van Halsema specializes in project development, environmental and environmental law, and general administrative law. She advises and litigates for project developers, construction companies, investors and governments. She also regularly assists developers and governments in negotiating area and project developments and writes or reviews related contracts.

Tosca graduated from Maastricht University in 2013 with an honours degree in Constitutional and Administrative Law and European Law. After graduating, she took up a position as a lawyer in the Competition & Regulatory practice group at Loyens & Loeff in Rotterdam. Tosca joined Straatman Koster advocaten in September 2019.