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In 1966, Jan Tanghe, Jacques Pêtre, Ignaas Deboutte and Willy Canfyn  took up the challenge to create an interdisciplinary group, called ‘Groep Planning’. A team of architects, urban planners and engineers worked together on numerous complex projects transcending the classic structure of a design agency and aiming to develop a global vision about (urban) space. The multidisciplinary character of the team was highlighted in 1995 with the integration of ‘Mens en Ruimte’, a team of experts in the field of energy, environment, mobility, agriculture and horticulture, sociology, economy, geography and planning.


Today, 50 years later, the three partners, prof. Paul Lievevrouw, Jean-Pierre Mariën and Jan Jonas-Szatanski, affirm, once again, the sum between SumProject and SumResearch. Sum stands for the continuous intertwining of scientific research and research by design. The cross-functional team ensures the sustainable scale of the projects, an overall quality management, sound budgeting in an economic reality, an efficient project management and a clear communication strategy.


SumProject offers sustainable architecture, engineering and urban design. Based on profound contextual studies, SumProject's designs aim to improve the living and working environment.


SumResearch is specialised in urban consultancy, masterplanning, strategic policy planning for both the public and private sector.


SumProject+SumResearch is  active in Flanders, Brussels, Wallonia and northern France.

Paul Lievevrouw

Prof. Paul Lievevrouw, architect, Master of Science in Conservation, chairman and director of  Sum-Project+SumResearch and professor at KULeuven: Faculty of Architecture and Centre for Conservation Raymond Lemaire. With almost 40 years of experience, Paul is the driving force behind architectural projects (new construction and restoration), large masterplans, feasibility studies and urban development visions and projects.



Jean-Pierre Mariën

Jean-Pierre Mariën, architect, director of SumProject+SumResearch and architectural projects manager is responsible for complex execution plans in which he devotes special attention to the architectural expression and detailing.



Jan Jonas-Szatanski

Jan Jonas-Szatanski, Polish engineer-architect with an extra degree in heritage conservation. As a partner of Sum, Jan is project manager of numerous projects in which he develops the general spatial layout and the architectural concepts.

Through his experience Jan has achieved a particular expertise in the development of complex urban projects.





prof. Paul LIEVEVROUW (Arch. - Chairman and Director)

Jean-Pierre MARIEN (Arch. - Director)

Jan JONAS-SZATANSKI (Arch. - Partner)


Marc APPELMANS (Business development)

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