Attorney at law, Partner

Maayke Maas-Cooymans


Maayke is active in the fields of environmental licensing law, spatial planning law (Spatial Planning Act, Housing Act, etc.) and environmental law in the broadest sense (IPPC, waste, reach, Environmental Impact Assessment procedures, environmental reporting, environmental permit procedures and enforcement, general administrative procedure and constitutional law (including freedom of government information). She is a member of Ploum’s energy rights team. In addition, she regularly publishes and edits various administrative and environmental law publications for Sdu and Euroforum, respectively. Maayke is a member of the NOVA Administrative Procedure working group. Finally, she teaches for Erasmus University Rotterdam, the vocational training programme in Law, OSR Utrecht, Sdu Opleidingen and delivers advocacy training and in-house courses. 

In April 2012 Ploum was awarded as ‘Environmental Law Firm of the Year 2012’ in the Netherlands by Corporate INTL legal awards.

What clients say about me

Maayke Maas-Cooymans advises clients on contentious and non-contentious environmental permitting matters, as well as acting on emissions regulations, zoning plans and waste management matters. – Chambers 2021

"Maayke Maas-Cooymans is an outstanding partner."  – Legal 500 EMEA 2022

"Maayke Maas-Cooymans is very knowledgeable and responsive." – Legal 500 EMEA 2022

"Maayke Maas is Mrs Environment in the Netherlands; she is very knowledgeable, practical, experienced and a pleasant and pragmatic person." – Legal 500 EMEA 2022

"Maayke Maas-Cooymans is extremely knowledgeable in this areas of law." – Legal 500 EMEA


Maayke graduated from Utrecht University in 1997. She gained work experience during successive spells with Trenité Van Doorne, De Brauw Blackstone Westbroek and Simmons & Simmons, before joining Ploum as a lawyer and partner in 2008.


  • ‘Vierde tranche Algemene wet bestuursrecht (handhaving)’, Maayke Maas-Cooymans, Cornelis van der Sluis, Marike Bakker, Jeroen Langeveld en Hugo Pennarts, Sdu, juni 2010
  • ‘Wet openbaarheid van bestuur: Jurisprudentie 2009 tot begin 2010 inzake de weigeringsgronden en beperkingen’, Maayke Maas-Cooymans, De Gemeentestem 2010/32, april 2010
  • ‘Wet openbaarheid van bestuur in de praktijk. Een praktisch overzicht van mogelijkheden, verlichtingen en valkuilen’, Maayke Maas Cooymans, De Gemeentestem 2010/24, maart 2010
  • Annotatie bij Afdeling bestuursrechtspraak van de Raad van State van 1 september 2010 (LJN BN5684), Maayke Maas-Cooymans en Cornelis van der Sluis, De Gemeentestem 2010/99, oktober 2010
  • ‘Commentaar Algemene wet bestuursrecht’, Maayke Maas-Cooymans, Sdu, augustus 2011
  • ‘Commentaar Wet openbaarheid van bestuur’, Maayke Maas-Cooymans, Sdu, juli 2011
  • Annotatie uitspraak ABRvS 1 juni 2011 (overgangsrecht vierde tranche), Maayke Maas-Cooymans, Gemeentestem, Kluwer, september 2011
  • ‘Is uw Winkeltijdenverordening ‘WTW-proof’ voor 1 januari 2012?’, Maayke Maas-Cooymans, Gemeentestem, Kluwer,  126, december 2011
  • ‘Noot ABRvS 14 december 2011 aanvang redelijke termijn’, Maayke Maas-Cooymans, JB (Sdu), februari 2012
  • ‘Jurisprudentie in Nederland’, Maayke Maas-Cooymans, Sdu, april 2012
  • ‘Handhaving voor en door gemeenten’, Maayke Maas-Cooymans, Vereniging Nederlandse Gemeenten, oktober 2013
  • ‘Brzo wetgeving en relevante documentatie’, Maayke Maas-Cooymans, Sdu, mei 2014
  • ‘Het melden van ongewone voorvallen’, Maayke Maas-Cooymans en Brigitte Ebben, Tijdschrift Omgevingsrecht, december 2013

The Netherlands Bar’s register of legal practice areas (rechtsgebiedenregister)

Maayke Maas-Cooymans has registered the following principal (and secondary) legal practice areas in the Netherlands Bar’s register of legal practice areas (rechtsgebiedenregister):

  • General practice (algemene praktijk), sub legal practice area administrative law (bestuursrecht);
  • Environmental law (omgevingsrecht), sub legal practice area environmental law (milieurecht), sub legal practice area spatial administrative law (ruimtelijk bestuursrecht), sub legal practice area water law (waterrecht).

Based on this registration, Maayke Maas-Cooymans is required to obtain ten training credits per calendar year in each registered principal legal practice area in accordance with the standards set by the Netherlands Bar.

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