Last year, we published a guide about Revit coordinates. It became one of the most visited blog post on this website, ever! It turns out that everyone is really confused about Revit strange coordinate system. In the previous guide, we covered all the basics: the difference between Project Base Point and Survey Point, exporting and importing files in relation to coordinates. Make sure to read the guide to get familiar with the basic notions:

In this post, we will dig much deeper into a specific aspect of coordinates: Shared Site. You will learn how to properly link multiple files together using the shared coordinates system. This post has a full video tutorial if you are interested:

Before we get started with the steps, let’s explore what is actually a shared site.

THE MYSTERIOUS SURVEY POINT

There are multiple ways to use the Survey Point. The way we recommend is that you always keep it clipped. This way, it will always match the Shared Site Origin of the project. If you move an unclipped Survey Point, you will probably cause confusion in your project.

WHY USE SHARED SITES?

Have a look at the image below. There are 3 different Revit models: two building models and a site model. Each building has a specific local Project Base Point and Internal Origin, most likely located at the same location.

The shared site origin position is set in the site model and represented by the Survey Point. Then, each building model is positioned and the shared coordinates are acquired from the site model.

Why would you use this Shared Site feature? Here are the benefits:

SHARED SITE BENEFIT #1: SPOT COORDINATES REFER TO THE SAME POINT ON ALL MODELS.

In the image below, we use the Spot Coordinate tool, located in the Annotate tab. It will indicate the X/Y distance from a point to the Shared Site Origin, which is represented by the Survey Point.

When the Shared Coordinates are spread among all the Revit files, the spot coordinate tool can be used in any model and still refer to the same origin point.

Be careful: there can be multiple types of Spot Coordinates. In the type properties, make sure that the Coordinate Origin is set to Survey Point.

BENEFIT #2: SPOT ELEVATION REFER TO THE SAME POINT ON ALL MODELS.

It is helpful to spot the elevation of a building element in relation to the site. In the example below, we place the elevation value of the Shared Site Origin (represented by the Survey Point) at Sea Level = 0. This way, we can use the Spot Elevation tool to indicate the height of any element in relation to the sea level. Spread the Shared Coordinates to all Revit files and you’ll be able to use this feature accurately on any model.

Like with the Spot Coordinates tool, make sure to use Survey Point as the Elevation Origin in the Spot Elevation type properties.

BENEFIT #3: MODELS CAN BE LINKED USING “BY SHARED COORDINATES” POSITIONING

The Shared Coordinate system is like a virus that spreads around. The virus starts from the linked Revit site Model. It then spreads around to the architecture model, to the structure model, to the linked CAD files, etc. Once the virus infected all the models, you can link any file together and they will automatically position themselves if you use the Auto - By Shared Coordinates positioning option.

Again, this positioning option only becomes available when the files have been synced using Share or Publish Coordinates. You will learn how to do so in the coming pages.

BENEFIT #4: THE “TRUE NORTH” CAN BE SET IN THE SITE MODEL BY USING THE ROTATION TOOL

All Revit projects contain two norths:

• The Project North is used to orient view in a convenient way in relation to the sheets.

• The True North represent the real world north in relation to the site.

The most common way to set the True North value is to manually set a rotation angle value between the True North and Project North. However, there is a more simple way to do so: you can link your architecture project on the Revit site model, rotate it and publish the coordinates. Just make sure the view where you rotate the building is set to True North.

When coordinates are shared, you can go back to the Architecture model and adjust the Orientation parameter In the instance properties of a plan view. Pick between Project North and True North.

SHARED COORDINATES VS SHARED SITES

Shared Coordinates and Shared Sites are not the same thing. In the image below, there is a site model and 2 instances of a building model. Each of these files are all using the same Shared Coordinate System. However, each instance of the Revit building model has its own Shared Site. Basically, all files have a common Survey Point but they also have their own personal Project Base Point and Internal Origin.

Now that you understand what is a Shared Site, let’s create one. Have a look at the chart below. Then, we’ll get going with the 14 steps to create a shared site.

1. CREATE ARCHITECTURE MODEL, LOCATE ORIGIN

The first step is to create the main architecture model. Orient the views for convenience and ignore the true north for the moment.

The most important step is to place the building in relation to the internal origin. Usually, that means at the corner of your building, where two major grids might intersect. Don’t mess up this step. You cannot relocate the internal origin of the project.

2. LINK REVIT MODELS FROM ALL DISCIPLINES USING “ORIGIN TO ORIGIN”

If you have MEP and Structure models ready, you can link all the Revit files together. Use the Auto – Origin to Origin positioning option. Always use this option and you will never have positioning problems when linking multiple disciplines. Don’t worry about shared coordinates for now.

3. CREATE SITE MODEL AND LINK CAD SURVEY DATA

Once you have the Survey Data from your civil engineer or surveyor in hand, create a new Revit site model. Make sure the origin in the CAD file containing the survey data is where it needs to be. In this example, we will use a 2D CAD topo file, although you might sometimes receive 3D files.

In this surveyor DWG file, the origin (0,0) is located at the corner of the property lines. This is the agreed location of the shared site origin. The default Revit origins are all at the same spot. Then, use the Link CAD tool and use Manual - Center positioning option. Click to place the DWG file.

Now, go to the manage tab, click on the Coordinates icon and select the Acquire Coordinates tool.

Then, click on the CAD link. As you can see, the Survey Point of the Revit site model is automatically moved to match the CAD file origin.

4. MODEL TOPOSURFACE USING CAD FILE

Now, let’s model the topography of the site using the Toposurface tool, located in the Massing & Site tab. Click on the Create from Import tool and select the CAD file. Select the correct CAD layer, in this case we know it is layer TOPO.

Thousands of points will be automatically created. In this case, this is a 2D CAD file, which means you still have to manually set the height of all these points. Use the sea level information to set the proper height to the points on each curved line.

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5. SET SURVEY POINT TO ELEVATION = 0

In most cases, you want the Survey Point height to be set to level 0. This way, you can use it to indicate the Sea Level elevation of any point. In your Revit site model, go to any elevation and uncrop the view. Activate the Survey Point visibility in the Visibility Graphics menu, under the Site subcategory. Select the Survey Point and make sure it is clipped. Move it to Level 0. Make sure you don’t modify the X/Y coordinates of the point.

Depending on how your Revit template is set up, the Survey Point might already be set to Level 0. It should match the Internal Origin elevation.

6. LINK AND POSITION THE ARCHITECTURE MODEL

Use the Link Revit tool in the Insert tab. Select your architecture model and use the Manual - Center positioning option.

Now, manually position the building on the site model.

7. ROTATE THE ARCHITECTURE MODEL IF NECESSARY

We’ve talked about how you can set the True North of a project using the rotation tool inside the site model. It is now the time to rotate your model if necessary

8. ADJUST THE BUILDING VERTICAL POSITION

Go to an elevation view. Figure out what Sea Level elevation will match the Level 1 of the architecture model. Create a new level in the site model and call it “Building A”. In the example below, we know Level 1 = Sea Level 7600mm. Align and lock the architecture model Level 1 to this new level. With this technique, adjusting the building height in relation to the site becomes pretty easy.

9. PUBLISH COORDINATES TO ARCHITECTURE MODEL

You have linked an architecture model, properly positioned it on the site and adjusted the rotation value. Now, it is time to Publish the coordinates from the site model to the architecture model. Select the linked architecture file. In the instance properties, you will find the Shared Site parameter. Click on it.

When clicking Shared Site, here are all the options available to you:

In this case, you should pick the first option: you want to publish the coordinates from the Site model to the Architecture model. Basically, this will move the survey point in the House model to be in the same position as the site model. The operation will only be complete once you close the Site model: you will be asked what to do with the linked house model position. Select the first option.

It’s a good idea to verify if the publish coordinates tool worked as intended. Open the architecture Revit model. Normally, the Survey Point has been moved to reflect the position in the site model.

Try to set the view orientation to True North. It should match the north you’ve set with the rotation tool in the site model.

10. OPTIONAL: CREATE MULTIPLE INSTANCES OF THE SAME ARCHITECTURE MODEL

You can have multiple instances of the building on the same site. In the Revit site model, copy and paste the building instance. Adjust the position, both in plan view and in elevation.

Now, you have to create a new Shared Site. Click on the Shared Site button in the instance properties of the linked model.

Use the “Record current position...” option and click on “Change...”.

You now have access to the Site menu of the linked architecture model. Click on Duplicate.

Enter a name for the new Shared Site. Click on OK.

To verify everything is right, open the architecture file. Select the Survey Point and click on the blue text “Survey Point - Internal”. There will be a list of multiple sites. Select “Site 2” and click on Make Current. The position of the Survey Point and the True North angle will be updated to reflect the position you have set in the Site Model.

11. STRUCTURE AND MEP MODELS ACQUIRE COORDINATES FROM ARCHITECTURE

Now, let’s acquire the coordinates from the Architecture model to the Structure and MEP models.

In the example below, you are inside the structural model. The Architecture model is already linked inside (using Origin to Origin positioning option). Select the Architecture model and click on the Shared Site parameter in the instance properties. This time, you have to use the Acquire tool instead of Publish. You want to acquire the shared coordinates system of the Building-A architecture file.

Congratulations, all the Revit models are now using the same Shared Coordinate system! That means you can link any of these files together using the Auto - By Shared Coordinates positioning option. In the image below, you can see our Structural model with the linked site model.

12. LINK SITE MODEL INTO STRUCTURE AND MEP MODELS USING “ BY SHARED COORDINATES” OPTION

Congratulations, all the Revit models are now using the same Shared Coordinate system! That means you can link any of these files together using the Auto - By Shared Coordinates positioning option. In the image below, you can see our Structural model with the linked site model.

SITES WITH MULTIPLE BUILDINGS

Sometimes, you might have a site that contains multiple buildings .The workflow remains similar:

1-Create the architecture project.

2- Create a site model, set shared site origin and model toposurface.

3- Link the architecture model inside the site model.

4- Manually position the building inside the site.

5- Publish the coordinates from the site to the architecture model.

6- Spread the coordinates from the architecture file to the other disciplines. Link all files together using Auto - By Shared Coordinates.

Repeat these steps for all buildings. Each building has a unique shared site.

This article was originally published on RevitPure and has been republished here with permission.

cover image © unsplash