is an Amsterdam based partnership of independent lawyers.
We are specialized in real estate transactions, administrative law,
environment & planning, mediation and employment law.

Our Services

Commercial Real Estate

Commercial Real Estate

Source has extensive experience in all legal aspects with regard to commercial real estate. We advise and assist investors and developers in all facets and challenges of acquiring, selling, constructing and ownership of commercial real estate. Our core competencies include commercial real estate transactions, contract law, rental law, litigation & arbitration, procurement law and construction law.

Administrative Law, Environment & Planning

Administrative Law, Environment & Planning

Source has extensive knowledge and experience in the field of general administrative law, environment and planning. Our team advises government bodies, project developers and other companies. Our Environmental & Planning Team’s work includes advice on issues as part of large national and cross-border real estate transactions. Our specialists are also known for their litigation expertise and experience in licensing and enforcement procedures.



Bas Derhaag combines his work as an employment law lawyer with conducting an intensive mediation practice. As a certified mediator he deals with various types of disputes and conflicts, with an emphasis on labor disputes, problematic relationships between shareholders, members of a partnership, the management and the (central) works council of a company, or between (and within) an executive board and a supervisory board. His many years of experience as a lawyer is of great added value in this respect. His knowledge of law, professional and interpersonal relations and business interests contributes to the success of most of the mediations he conducts. Click here for more information about mediation.

Employment law

Employment law

Source advises, negotiates and litigates on labor issues. This includes individual and collective employment law, employee participation and other forms of professional cooperation, such as assignments and partnerships. The clients are Dutch and international companies and non-profit organizations, but also employees, contractors and other professionals, such as statutory directors.

Our Team

Cheryl has been practising law for over 20 years, gaining experience at reputed law firms. She has a strong experience in real estate transactions, providing legal guidance on the entire process of property acquisition and selling, such as performing transactional due diligence, thereby assessing legal risks that pertain to leasing and property title, drafting and reviewing and negotiating sale and purchase agreements while ensuring compliance with current legislation. Furthermore she provides clients with litigation support and legal advice pertaining to commercial real estate issues.

Frank has a broad administrative law background gaining experience with the Council of State in The Hague, as legal counsel with a large project developer and 25 years as a lawyer working for two large law firms. He is a specialist in environmental and planning & zoning aspects of real estate, especially in the sphere of complex project- and area developments (both commercial and residential), infrastructural projects (railways, roads, dykes, windmill farms, etc.). He advises frequently on public and private law issues as part of national and cross-border real estate transactions. Frank is a recognised administrative law specialist and is involved in cases ruled by administrative procedure law, such as disputes with regulators in the field of energy, telecom, privacy, pharma and finance.
Mr. Leyendeckers does not receive any third party funds.

Erika is a very experienced lawyer in the field of environmental law. She studied Dutch law and Environmental Science at Utrecht University and has been a lawyer since 1999. She is a specialist in planning law, environmental law and general administrative law. For example, she regularly advises and litigates on (large) spatial developments in the areas of housing, offices, industrial estates and retail trade. Enforcement procedures also belong to her specialism. In addition, she advises on matters in the field of general administrative law, such as Freedom of Information Act (Wob), subsidy issues, etc.
She teaches among others at the NEPROM, the Berghauser Pont Academy and Geoplan and also regularly gives lectures for other organizations or in-house workshops. Furthermore, she is a member of various professional associations.
Erika works for both public and private parties such as project developers, industrial companies and retailers and therefore oversees all the different interests and positions that play a role in the broad field of planning and environmental law. Clients appreciate Erika because of her high level of involvement and clear advice.
Mrs. Samuels Brusse does not receive any third party funds.

Bas has over 25 years of experience as a specialist in employment law. He is known to have a nuanced view on matters. He litigates regularly, but in most cases he knows how to achieve a good result without the involvement of the courts. His clients are Dutch and international companies and non-profit institutions. He also assists private individuals, mostly managers and directors of legal entities. His clients value him for his commitment, integrity and solution-oriented approach.
Bas has been a lawyer since 1995. Before joining SOURCE in 2019, he worked for Baker & McKenzie, Houthoff, and Vestius Advocaten, among others.
Besides being an attorney at law Bas is certified mediator. In this role he focuses in particular on the resolution of disputes within employment relationships and other forms of professional cooperation, conflicts in the field of employee participation, within a board or in a team. Click here for more information about mediation.
Mr. Derhaag does not receive any third party funds.

Fred has gained more than 19 years practical experience in the field of construction law, project development and area development while working for 4 large construction companies and project development companies before he made the switch to legal counselling in 2007.
As legal counsel Fred counts among his clients construction companies, project development companies, housing corporations, private investors and municipalities.
Fred is familiar with a broad spectre of contract types and forms of cooperation (complex or not) in the field of area development, project development and the construction industry and is able to deliver custom solutions, as well in drafting contract documents as in considering/reviewing contract documents of third parties. If desired Fred plays an active role in conducting negotiations with counterparties and/or cooperation partners.
In common cases Fred conducts legal proceedings for his clients at the civil courts, the Arbitration Board for the Building Industry and the Dutch Foundation for Consumer Complaints Boards (Guarantee Houses).
Freds motto says: “Better be adequate than bureaucrat!”
WiSe Legal B.V., Fred’s practice company, has no connection to a third-party foundation and does not receive any third party funds.

Contact Us

advocaten │ attorneys-at-law

t +31 20 5300160

f +31 20 5300170

P.O. Box 75538, 1070 AM Amsterdam

Anne Frankstraat 121, 1018 BZ Amsterdam is a strategic partner of SOLV

Under the trade name the practices with corporate personality Advocatenkantoor Virtu B.V. (KvK 34272334), Franklin’s Law B.V. (KvK 34251332), Bas Derhaag Advocatuur en Mediation B.V. (KvK 34233637), ESB Legal B.V. (KvK 71726608) and WiSe Legal B.V. (KvK 53300327) practice law. On all of our services our general terms and conditions are applicable, which terms and conditions contain a limitation of liability.
Please find our complaint handling procedure here.