Further to my previous post “How to prevent your ARCHICAD model from becoming detached from Sea Level” I was asked to follow it up with an example.
For the example, I decided to use the project file supplied by GRAPHISOFT, Volume 5 – Using Teamwork. The building used is the Microsoft Office Complex in GRAPHISOFT Park, Budapest, Hungary. That way any reader of this article can download the file for reference purposes if they so wish.
Let’s first look at the correct way with the use of Project Zero using Story 0 = Ground Floor slab (street level). It uses a logical story relationship of Story -1 = Basement, Story 1 = First Floor, Story 2 = Second Floor, etc.
Looking at any of the sections or elevations one can see the “0 Ground Floor = 0.00 setup using Project Zero / Reference Level.
The next step is to insert a Sea Level reference. The default settings for Project Location are indicative that it has not been setup to match Google Maps. For now, I am just going to insert the value of 10 m for “Altitude (Sea Level):
Then looking at any of the Elevations or Sections to see the Sea Level relationship, if one selects all four sections in the Project Map and right-click (context menu) the option “Section Settings…” then under the drop-down menu STORY LEVELS > Reference Level change the option to Sea Level.
Now when opening any of the Sections one will see the logical story relationship of -1 Basement +6.40, 0 Ground Floor +10.00, 1 First Floor +13.60 etc to Sea Level.
When opening the layout A-06 Section one will see that the four sections will update to show the 10m to Sea Level reference. But please note the section to layout placement is not affected by the addition of 10m.
Therefore making use of the Relative Level – Project Zero = Ground Floor and changing the Sea Level value will not have a knock-on effect of the building model moving up or down, including layouts becoming disassociated. In other words, Sea Level moves up or down not Project Zero.
Example 2 (Not recommended)
Using a sacrificial story named Datum / AHD to “push-up” the building model to sea level. To achieve this, I opened Story Settings and inserted two stories above 0 story by selecting it and clicking “Insert Above” twice. Then I used the “Edit Element by Stories” found under the Design menu to cut & paste from Story 0 to Story 2 and Story -1 to Story 1. Then I typed in the letters Datum/ AHD into the name field for Story 0 and renamed Story 1 Basement and Story 2 Ground Floor.
Please note: that elevations and sections have moved in relationship to the 2D drafting work that was placed on them to clean them up. Including “Elevation levels” have become disassociated. For the screenshot example below I used trace & reference to illustrate the issue of using 0 Story as a Datum / AHD.
Last but not least making any adjustment to the use of Story 0 as Datum / AHD is going to affect the entire building model and document set. Working for a large Architectural Practice like Plus Architecture, I can tell you that disassociated document sets are not appreciated by anyone.