Defining project zero and/or site zero

[Johan Stinckens]

I'm trying to work out how to set up larger development projects. Specifically what to use as a reference point for exchanging BIM information with surveyors, engineers, contractors,...

Having several buildings on a large site, what would be the best approach on defining the zero point?!

Proposal 1: having a project zero for each of the buildings (preferably a specific corner of the building or the crossing of two axes).

Proposal 2: a site zero to which all other buildings refer to.

Proposal 1 seems easier to set up. You can start designing the building right away, with no need to have specific info about the site apart from the footprint of the building. Upon creating the site plan you will have to position the building accordingly, moving and turning until it sits in the correct location.

Proposal 2 is a bit more work to set up and a team can only start designing the buildings after they are provided with the exact location of that building.
There's however the benefit that every building has its North defined correctly (ideal for shadow studies and energy calculation), and that adding other buildings can be done according to the one Site Zero (placement of PMK's, modules,...)

In both examples I would use a PLN file for each of the buildings and one PLN for the site plan in which the buildings would be linked either as a module (generation of terrain profiles) or as PMK's (site plan).

Any ideas on either of the two? What works best for you?

kind regards,

Johan

[Johan Stinckens]

Sidenote: what about Z-levels?

How do you reference the buildings to a correct level? Each seperate building uses Project Zero as its own default level. Can one use Sea Level as a reference level to attach the seperate buildings to the Project Site on its correct level?

[Erwin Edel]

You need a masterfile for the siteplan and hotlink the different buildings in to that. Just position them all according to sea level or a reference level (in NL we use NAP).

Ussually your buildings will not have the same story settings.

I generally solve this by having a 'cross link' pln where I hotlink single stories of my buildings to one story (stacking them at the right height) and save out a single story module that contains the whole building. This requires some 'weird' modelling some times in terms of what is linked to what story in the mainmodel to deal with SEO / trimming.

It's not ideal, but once you've set things up, you'll never have to go back to that 'cross link' file, as nested modules will just update.

You'll also need to manage attributes among different PLN files, as they will not update along with modules.

Sometimes it is easier to create new attributes in your master siteplan file, as it should contain all of the attributes of all the buildings and just copy an element with the new attributes over to the individual building PLNs.

Meanwhile, back in the real world, you probably started drafting up the buildings first and then remembered you needed to combine them all in some sort of siteplan (happens with our office a lot!!). Better start planning how to manage things sooner than later!

[sinceV6]

Hi.

Johan wrote:
Having several buildings on a large site, what would be the best approach on defining the zero point?!

Proposal 1: having a project zero for each of the buildings (preferably a specific corner of the building or the crossing of two axes).

Proposal 2: a site zero to which all other buildings refer to.

You need both. Site origin will help you deal with the master plan issues of locating, placing and orienting buildings. Each building's project origin will relate to the site origin. You could have each project origin have its own set of coordinates (preferably in a gridline crossing, not a building corner) as this will help you when coordinating the rest of the disciplines, and you just need a note on how each building relates to the site origin. As for Z levels, it is easier to use and relate every level to the site origin in writing, but keep each building main level in Z=0, so you can work each building separately to coordinate everything else. Hope it is clear.

Best regards.

[Anonymous]

Hi there

Generally the site location is defined in lat/lon and is based on wgs84 Geoid, the one google earth uses. Based on this, to be able to combine models in larger projects your project zero has always to be a corner of your site. That way you simulate reality. Buildings are not refered to each other in any system. Buildings are refered to site boundaries. The land is referenced on a coordinate system which if you use consistently on your projects you will be able to make a puzzle and all pieces will be positioned based on the world coordinates you have given.

"Try this. Make two projects. Your house with the site and your neighbour's house. Give correct coordinates in any corner of each project that you chose to be project zero. Then insert one of the projects as a module to the other one and chose it to be placed to it's original location. see what will happen."

Well this is not actually true. I tried it my self, either by loading as a module or by drag and drop a pln on another floorplan. Neither of the methods worked because archicad does not ask if you want to place them to its original location, like it does with dwg.

Regards

[Anonymous]

Tip

to place the site model close to project origin open up an excel file, make a table with the site coordinates and another one where you will deduct the values that you chose as site location from all other coordinate values for x and y respectively. This way you will get the coordinates of your site relative to project zero or site location. these values have to be inserted in the place mesh from surveyors data and your site although positioned to project zero, the whole pln file has a certain site location relative to the world coordinate system.

Regards

[Johan Stinckens]

Johan wrote:
Sidenote: what about Z-levels?

How do you reference the buildings to a correct level? Each seperate building uses Project Zero as its own default level. Can one use Sea Level as a reference level to attach the seperate buildings to the Project Site on its correct level?

I am still puzzled about the usage of Sea Level. OK, I can use it in a project to position de model correctly (location). But I would imagine that I could also use it to reference several models to one site plan having them all sit at their correct elevation.

Example: 3 buildings on one site, all of them having a base floor level 30cm higher than the adjacent building. Story 0 for building A: 23,90m above sea level, Story 0 for building B: 24,20m above sea level, Story 0 for building C: 24,50m above sea level.

What I created in ArchiCAD, and hoped/expected would do the trick.

Siteplan.pln -> for convenience I've set Sea level to 23,90m -> identical to the building which sits the lowest on the terrain -> placed a terrain 150mm lower than project zero (so 23,75m above sea level)
Test_01.pln -> contains a cube (Building A) with its base set tot Story 0 / Sea Level: 23,90m
Test_02.plan -> contains a cube (Building B) with its base set tot Story 0 / Sea Level: 24,20m
Test_03.pln -> contains a cube (Building C) with its base set tot Story 0 / Sea Level: 24,50m

Adding all the buildings as a module to the siteplan.pln I hope Building A would sit just 15cm above the terrain, Building B would sit 45cm above the terrain and Building C would sit 75cm above the terrain.

Anyone?!

[Anonymous · Accepted solution]

Johan wrote:

Johan wrote:
Sidenote: what about Z-levels?

How do you reference the buildings to a correct level? Each seperate building uses Project Zero as its own default level. Can one use Sea Level as a reference level to attach the seperate buildings to the Project Site on its correct level?

I am still puzzled about the usage of Sea Level. OK, I can use it in a project to position de model correctly (location). But I would imagine that I could also use it to reference several models to one site plan having them all sit at their correct elevation.

Example: 3 buildings on one site, all of them having a base floor level 30cm higher than the adjacent building. Story 0 for building A: 23,90m above sea level, Story 0 for building B: 24,20m above sea level, Story 0 for building C: 24,50m above sea level.

What I created in ArchiCAD, and hoped/expected would do the trick.

Siteplan.pln -> for convenience I've set Sea level to 23,90m -> identical to the building which sits the lowest on the terrain -> placed a terrain 150mm lower than project zero (so 23,75m above sea level)
Test_01.pln -> contains a cube (Building A) with its base set tot Story 0 / Sea Level: 23,90m
Test_02.plan -> contains a cube (Building B) with its base set tot Story 0 / Sea Level: 24,20m
Test_03.pln -> contains a cube (Building C) with its base set tot Story 0 / Sea Level: 24,50m

Adding all the buildings as a module to the siteplan.pln I hope Building A would sit just 15cm above the terrain, Building B would sit 45cm above the terrain and Building C would sit 75cm above the terrain.

Anyone?!

Make the site plan first. setup project location
position zones or morphs that represent the buildings
save each morph or zone as module.
open each module in different instance of archicad.
design your building.
save module.
open site plan with nested modules.

I think this is the correct proccess.

When you add an arbitrary module or a pln to another pln, project location is not read by the larger project.
The modules have to be created in the larger project so that they have common proect location but different absolut position from project origin.

I wish modules could have their own project location and when called by another project to be positioned relatively to their own project origin, in respect of the lat/lon coordinate system, the project position dialog uses.

Regards