Winket is a member of Bouwprojecteconomie (Construction Project Economy).

Bouwprojecteconomie is a cooperative of eleven independent construction cost consulting firms across the Netherlands. All bureaus are affiliated to NVBK, the Dutch association of construction cost experts. The bureaus have their data and calculation methodologies for construction and environmental costs accommodated in EcoQuaestor, a joint model with database. They also share (market) knowledge and experience in current construction projects with each other. In this way Bouwprojecteconomie has a knowledge potential that far exceeds the capabilities of an individual bureau.


EcoQuaestor is the approach of Bouwprojecteconomie for determining environmental impacts in relation to the cost of construction projects. But it’s more than that…

  • With EcoQuaestor the environmental load can be calculated according to the standards of the Building Act (het Bouwbesluit).
  • The construction costs of your project can also be calculated with EcoQuaestor.
  • EcoQuaestor is in line with NEN 2699.
  • In EcoQuaestor, the specifications of the technical solutions are encoded with STABU-short text codes.
  • Data in EcoQuaestor have been elaborated to a level suitable for calculations (eg m2 and pcs) and environmental calculations (kg material).
  • EcoQuaestor is available for BIM products such as ArchiCAD, Revit and Solibri and the specifications package Kubus Stabu 4 Element.
  • EcoQuaestor is supported by eleven construction costs bureaux of the NVBK.
  • The EcoQuaestor approach is in line with the international EPD method (according to NEN-EN 15804:2012+A1:2013 en).


Winket is a member of the Dutch Association of Construction Cost Experts (NVBK).

NVBK membership acts as a reliable certification for construction economists. NVBK opens for its members knowledge and information in the field and provides an interesting professional network. The NVBK represents the professional interests of its members in the Netherlands and internationally, and is committed to education in the field.

International Construction Measurement Standards

Tim de Jonge represents along with Creon Swaghoven (Assay Plan- & Vastgoedeconomie) the NVBK within the ICMS.


Tim de Jonge is president of the norm (sub-)committee NEN 2699.

NEN 2699 provides a breakdown of investment costs and operating costs of “immovable property” and their interrelationships. In this context “immovable property” refers to: areas, buildings with building-related plots. Boats and mobile homes are not covered. The system of this standard can also be used when not all cost categories are applicable, for instance in situations where land costs or installation costs play no role.

Mevrouw Meijer

Winket is the regular construction cost consultant of de stichting Mevrouw Meijer.

HU Hogeschool Utrecht

Tim de Jonge is posted in a part-time appointment at HU University of Applied Sciences Utrecht and works within that framework as a researcher on “Beyond the Current: user preference tested design solutions for energy efficient housing renovation”.


Winket is responsible for the schools of OBO – West Brabant, planning structural and installation technical maintenance.


NVBK is a member of the Council of European Construction Economists (Conseil Européen des Economistes de la Construction). CEEC was founded 35 years ago by a number of national institutions of construction cost experts, including NVBK.

CEEC aims to promote the professional construction cost engineering / construction economy in Europe. To promote good training and certification of professionals in the various countries is high on the agenda. In addition, the CEEC also acts as an intermediary between the industry and various EU organizations.

Representation NVBK: Tim de Jonge (Winket) and Creon Swaghoven (Assay Plan-& Vastgoedeconomie).


Winket is a member of the Bond van Nederlands Bestekdeskundigen, (Association of Dutch Specification Experts on Construction).

At some point in the design process, construction plans are established and specified in a contract between the client and the construction company that is going to build the project. Such a contract is refered to as the building specifications.
BNB promotes the quality of these specifications, represents the professional interests of specifiers and organizes meetings.