International Layer System

British standard BS 1192-5:1998 covers general guidlines for construction cad drawings, layers, linetypes etc. You can order it from British Standards Online.

I used the BS system before. Its OK in a large practice when everyone tries to use it. Its not very obvious (or doesnt even hint towards) what element is on what layer. There is a simplified version at the back of the RIAI good practice guide – looks pretty user friendly to me.

How does one go about getting a copy of the RIAI guide ?

Costomised systems are best as each office has a different methods of bringing documentation from planning to as-built. Compliance with any system can be managed by having all layers on a pull down menu , all linetypes and colours are by-layer. Layers are catagorised by discipline followed by element, then material, scale, new exist , demo. Sub catagories can go on indefinately depending on the size of the project. A simple project could have for example A-text-050 a large project could have A-zone_B-concrete-setdown-text-000. Drawings can be filtered to show only zone b elements, only concrete elements, the number refers to the scale details will be represented at, 000 means all scales.
With a well designed system, drawing model can be draw orthaganally, All plans have the same origin and sections and elevations are drawn perpendicular to the grid. Details are overlaid on large scale sections.
Cad drawings match hardcopies in that if i look for cad drawing a-156 it is called a-156.dwg and is a single titleblock with the CAD model referenced in. An investment of time in setting up a proper system pays dividends, especially with high staff turnover.

the layer system u have sounds very long winded to be honest but completely agree with the hard copy being named the same as cad copy

I used this system with a large international shopping centre developement company. The layer system was rigourously policed and it was quite complicated to get the hang of at the start. Unique sets drawings were produced for each trade, many x-refs were used, for instance individual drawings for 1. grids. 2 columns 3. blockwork 4. doors etc would be referenced into the drawing you were working on say floor finishes, this meant that many designers could work on the same plan simultainiously. Consultants drawings would be refernced in to show structure or M+E with co-existant origin and grids. References were brought in using a costomised dialogue box. In one drawing I had 40 references, yes complicated but worth it. I worked on precast and glazing for the entire perimeter and designed shop standard details of every component just by using the CAD model, communication was through the model, if you wanted it to be built, you drew it, simultainously the structural engineer updates the structural drawings, the fit out guys adjust their layout and when you look out the window you can almost see it being built. 15 architects, (5 or more irish) documented a job twice the size of Dundrum in 14 months and it was built in 13.

Orthaganol projection. if you reference the section/ elevation into the plan or vice versa, the walls and grid on plan line up with the section. Try it set up a site boundry and put a grid on it, Norting and eastings are your x+y grid andwill have an origin point, this will correspond with 0,0 on your CAD coordinate system. Next set up elevation and section grids. If you cut a section through east elevation looking north then you need to set up an elevation grid for it, it goes above the north boundry and its x gridlines correspond with plans, any sections or plans drawn looking north will sit on this grid, grids are set up for all directions you are viewing. One person administers site boundary and grid drawing, coz it is critical to the liason between site setting out and CAD drawing representation. You have a key of the overall plan or elevation/section in the corner of the titleblock. Hee haw agree with the drawing number-naming, i just like to cut out the practice of having 3 titleblocks on one cad file or having details copied to the side and worked on for a fax. Drawing numbering now is being dictated by web hosting systems anyway.

I hope i havn’t cause even more confusion, to restate my original point a bit better, a one size fits all solution for ireland needs to reconcile the conflicting requirement of flexibility for a diverse workload and strick adherence to protocol for consistancy.