Founded in 1968 by Marcel Pirnay, our team of more than 30 members is specialised in structural and civil engineering, building services and energy optimisation of building. Having large experience, we concentrate our activity exclusively on engineering.

The group contains two independent firms: Bureau Pirnay SA and Poly-Tech Engineering SA.

The activity of Bureau Pirnay SA includes structural and geotechnical engineering, mainly in Belgium and in the north of France.

Poly-Tech Engineering SA lays the emphasis on a multidisciplinary approach, carrying out the engineering of the whole of the technical installations of all types of building: HVAC, electricity, plumbing, fire prevention, access control, intrusion, elevators and so on.

The energetic analyses such as feasibility analysis, the evaluation of energetic performance of buildings and building auditing are done in combination with the building services engineering.

Poly-Tech is a founder member in the “Passive House Platform”. Its know-how and experience in the domain of passive building are reflected in various project such as the school Les Trèfles in Bruxelles, the education centre IFAPME in Mons, the headquarters of CSC in Jemappes and the building Green Wall in Gembloux.

Our service quality, availability, reactivity are certainly one of our main values. Our main goal is the satisfaction of our clients. We use internal quality measures which are client oriented, allowing us to increase our efficiency in this regard. The COQUAL certification that we possess (awarded by Construction Quality ASBL) is an example of our constant quality evolution.

Our group structure allows us to team up on all types of projects and of all size and degree of complexity. Whether these are apartment or office blocks, industrial buildings, hospitals, homes for elders, infrastructure, tunnels, bridges, restauration of building including classified ones, our team works as close as possible to our partners, architects, developers, contractors and sub-contractors.

Our objective of a long term vision, is creating a durable relation with the client and all partners on a project, by maintaining a clear attitude of proactivity, efficiency and loyalty towards our partners and towards ourselves and by respecting our commitments.



  • 1968 : Foundation of the company by Marcel Pirnay
  • 1978 : The company opens its office in Rue du Parc, Charleroi
  • 2005 : Jean-Sébastien Pirnay becomes chief executive officer
  • 2014 : Entry of new shareholders and a new office in Brussels
  • 2015: Poly-tech Engineering SPRL becomes Poly-Tech Engineering SA with Vincent Pirnay as chief executive officer
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