Site Plan help:DWG import, scale contol and WCS coordinating

[Aquavit]

Hi, I have a UK Ordnance Survey map, in 2D DWG format, which is to be the basis of my site plan & project.

I was planning to merge it into a lower story and use it as an underlay to draw up a 2d site plan initially and eventually graduating to a 3d terrain model with 3d buildings referenced in. Should I consider bringing it into a work sheet and tracing? I will be mostly referencing it but will also need to copy some elements off it to make up my new plot boundary.

I need to figure out what is the best scale to bring it in at to make it useful for the above processes, site is 55 acres. I'm coming back to Archicad after a few years in the wilderness on Microstation (similar to Autocad) - where all model space drawing is at 1:1 and its views and paper space elements that are scaled. Can I sensibly bring in vector data at 1:1 and work off it in ArchiCad?

I then want to locate the 2d vector OS map on the correct coordinates. So it is Geo-located and I can read off real time coordinate points from the map, import 3d terrain data, and locate the buildings at the correct coordinates during in the next stages.

The OS map is on the British grid system, can I set Archicad to those coordinates or is it only WCS?

Many thanks.

[Anonymous]

Aquavit wrote:
Hi, I have a UK Ordnance Survey map, in 2D DWG format, which is to be the basis of my site plan & project.
I was planning to merge it into a lower story and use it as an underlay...

1. Import it on an empty Worksheet at its original coordinates (File/External Content/Attach Xref...). This worksheet will be used to read real coordinates.

2. Repeat the point 1, only put it at coordinates x=0, y=0. This worksheet will be used as Trace Reference for your PLANS.

3. The entire Model is in scale 1:1! (you type the real dimensions). Only Views on the screen and final drawings on Layouts are scaled!

Aquavit wrote:
The OS map is on the British grid system, can I set Archicad to those coordinates or is it only WCS?

I don´t know nothing about British grid system, sorry.

ArchiCAD 14 can make 3D terrain from x,y,z data automaticaly, if your
Survey map contain this data.

[Aquavit]

andro55 wrote:
1. Import it on an empty Worksheet at its original coordinates (File/External Content/Attach Xref...). This worksheet will be used to read real coordinates.

Perfect thanks, brings it into the right location. To get it to scale correctly all I have to change the DWG translator to read DWG unit as 1 meter.

andro55 wrote:
2. Repeat the point 1, only put it at coordinates x=0, y=0. This worksheet will be used as Trace Reference for your PLANS.

I'm not sure I understand why I need a second copy of the OS map for the plans. Would I not model the various buildings/phases in a separate file and trace those into my Geo-Located site plan?

Cheers.

[Anonymous]

This is only a precaution. It is better to have all elements near to the Origin (0,0).

[Aquavit]

Understood, thanks.

Would you advise making the individual buildings as separate model files? So all their individual story/ split level heights are unique - and they can then be brought in as objects and inserted relative to the site levels?

[Anonymous]

In my practice I´ve modeled and saved each building separatly as modules (.mod), and then insert this modules in a master .pln (with 3D terrain) on different "z" haights.
All modules have the same story haights settings. First do a try what happens if this is not true!