Data structures for electronic product catalogues for building services
The standard ISO 16757 describes products of building services systems. It is based on the German standard VDI 3805, which has been used by manufacturers, software companies and designers in Germany for more than 10 years. ISO 16757 supports the digital exchange of product data that manufacturers have traditionally provided in the form of paper-based product catalogues or data sheets.
What is ISO 16757 about
The standard enables building services system designers to import the product data of different manufacturers into their design software. This product data allows the design and simulation of complex building services systems – on the basis of the data provided by the product manufacturer. An important aspect is the definition of dynamic properties which describe the behavior of such a product in dependence of some conditions of the surrounding system which can only be computed in a simulation (e.g. the pressure of the incoming air is one parameter which determines the pressure loss in an element of the ventilation system). Another aspect which is important to be dealt with is the big number of variants of building services products which require specific means to allow the parametric representation of products and their respective geometries. For this description, program functions are used.
Status of Parts
ISO 16757 is a multipart standard which is being developed by Working Group 11 in ISO/TC 59/SC 13. Parts 1 and 2 are already international standards. Part 1 defines the architecture and model and Part 2 defines the geometry which is based on the geometry of STEP (ISO 10303-42) and of IFC (ISO 16739). There are three further “infrastructure” parts under development:
- Part 3 specifies a script language to allow the exchange of algorithmic information about the behavior of products, namely the relationship between the value of dynamic properties and the surrounding conditions of the whole building services system,
- Part 4 describes the relationship of ISO 16757 to other BIM standards, and
- Part 5 defines the exchange format for catalog data.
In addition, a number of “content” parts will be developed, each related to a product group, e.g. air outlets or radiators. A content part defines basically the specific properties which are required to describe the products of that product group.
Adoption of ISO 16757 as a European standard
One of the current activities is to work towards an adoption of ISO 16757 as a European standard under the Vienna Agreement. CEN/TC 442 "Building Information Modelling (BIM)" has decided to put ISO 16757 under the Vienna Agreement. Now the ballots for the adoption of Part 1 and Part 2 are prepared, and upcoming new work items for the other parts will be submitted in parallel to CEN and ISO. Currently, connections to a number of European industry associations are established for this purpose.
Cooperation with other groups and initiatives
It is the goal to develop ISO 16757 in cooperation and in a concerted action with other activities around BIM and buildingSMART. In particular, it is the goal to harmonize the definition of properties with other standards and regulatory bodies, and in particular to support the use of property dictionaries as a location for the authorized definition of properties. As such, ISO/TC 59/SC 13/WG 11 works together with CEN/TC 442/WG 4 and some buildingSMART groups (buildingSMART Data Dictionary (bSDD), product data templates (PDT Task group)) to support the activities to put such an authorized dictionary in place.