Finnish implementation experiences

5.3.1 Background for the implementation

Studio Kivi is a small architectural design practice in Helsinki. CAD-systems have been used by the Studio for a number of years and experts from the firm have participated in national R&D projects as well as in the teaching of CAD-techniques to students of architecture. Studio Kivi has been testing a layering system based on ISO 13567 in several building projects since September  1995.

5.3.2 Adaptation of the ISO standard

Most of the CAD-layering implementations already in use in Finland have in some way utilised the national building element classification system (House 90). In the adaption of the ISO standard, the three first characters (one letter and two numbers) in the element field are consequently directly based on the Finnish standard element code. All five characters allowed for are not always necessary, but can in some cases be utilised. The recommendation is to use numbers as the two last characters, where 00 corresponds to the cases where the element is not specified.

In the presentation field, the possible values of the first character are already specified in the international standard. The second character is, however, open to national or company-specific adaptions. It can for instance be used for different levels of identification needed in different phases and plots of a project (0 = ID-number, 1 = type, etc.). The use of presentation for this purpose works especially well with attributes. This field could be used also for different languages in multi-lingual projects (quite common for Finnish design companies) by using letters (F = Finnish, R = Russian, S = Swedish, etc.). In the testing material suitable projects were unfortunately not at hand to test how useful this feature would be.

5.3.3 Development of prototypes

The prototypes were developed using AutoCAD version 12 for DOS and version 13 for both DOS and Windows.

The actual full layer codes resulting from the ISO standard are not easily human readable. For this reason an application with a user interface which provides full explanations to the layer contents is absolutely essential.

There are several reasons for this demand:

• the visible names must be comprehensible for the user.
• if the user writes the names directly, spelling errors will probably make the structure fail to be program readable.
• the structure of the name and the codes in every field must be checked.
• the new layer names must be recorded automatically for documentation and further use in the project.

An application was developed to fulfill these demands. The basic idea is to have a project database or even a simple ASCII file where each layer name, the color and the description of the use is recorded. When a drawing file is opened the data is read in and each actual layer name and the description is combined. In every possible place on the screen the user sees the description of the layer’s usage instead of the code name. AutoCAD’s common layer dialog is enhanced with a new dialog (figure 8).

The user can select the layers by their properties - color, element, presentation, status and description - or even a combination of those. When the user wants to create a new layer to the drawing, he can do it using the “Make” button, which gives a list of all pre-defined layers which are not yet in use in the drawing at hand. If a suitable layer does not exist, the next level “Create a new layer” gives the user the possibility to create a totally new layer and also to include it in the project database. All possible element, presentation and status codes and colors are available in the list boxes and the user can write any description to the new layer. All parts are checked before a new layer is accepted.