Revit MEP

Revit MEP

Friday, August 24, 2007

Tip When Creating Revit MEP Content

There are various family's that come out of the box with Revit MEP, and they work well when placed directly in an architectural model. But most consultants will link an architectural project into their MEP project, and element hosted families don't insert well into linked files.

For example, you cannot place a ceiling-hosted family on a linked ceiling or a wall-hosted family in a wall. The ceiling or wall needs to actually exist in the "host" model for you to be able to host a Light Fixture on it. This is how element hosting works in Revit.

The solution here is to use a Face-hosted Light Fixture family. Revit can detect the face of a ceiling through a link and therefore the Lighting Fixture can be hosted on that face.

Second, element-hosted families will be deleted if the linked element host is deleted. This is not true for Face-Hosted families. Face-Hosted families will be unhosted if their host face is deleted. which makes them sit in 3D space where they were originally. You can then re-host them to another face if you'd like.

So if you are creating your own MEP families, use a Face-hosted template so that your content can be placed in a linked file.

Following are the basic kinds of family templates:

  • Wall-based
  • Ceiling-based
  • Floor-based
  • Roof-based
  • Standalone
  • Line-based
  • Face-based
Wall-based, ceiling-based, floor-based, and roof-based templates are known as host-based templates. A host-based family can only be placed in a project if an element of its host type is present.

The wall-based template is for components inserted into walls. Wall components can include openings, such that when you place the component on a wall, it also cuts an opening in the wall. Some examples of wall-based components include doors, windows, and lighting fixtures. Each template includes a wall; the wall is necessary for showing how the component fits in a wall.

The ceiling-based template is for components inserted into ceilings. Ceiling components can include openings, so that when you place the component on a ceiling, it also cuts an opening in the ceiling. Examples of ceiling-based families include sprinklers and recessed lighting fixtures.

The floor-based template is for components inserted into floors. Floor components can include openings, so that when you place the component on a floor, it also cuts an opening in the floor. An example of a floor-based family is a heating register.

The roof-based template is for components inserted into roofs. Roof components can include openings, so that when you place the component on a roof, it also cuts an opening in the roof. Examples of roof-based families include soffits and fans.

The standalone template is for components that are not host-dependent. A standalone component can appear anywhere in a model and can be dimensioned to other standalone or host-based components. Examples of standalone families include columns, furniture, and appliances.

The line-based template is for creating detail and model families that use 2-pick placement similar to structural beams. For information about detail families with 2-pick placement.

The face-based template is for creating work plane-based families that can modify their hosts. Families created from the template can make complex cuts in hosts. Instances of these families can be placed on any surface, regardless of its orientation.


  1. Thank you for the tip. You may have just saved me many future headaches. Can you tell me though, when I create a new family of diffusers, how can I link the 'Flow' box that shows up on the options bar when an air terminal is selected with the properties for that air terminal? I cannot get this box to show me the CFM I enter for the air flow for any air terminal i place. Thanks.

  2. With a ceiling hosted element it will cut out the ceiling so that it is viewed properly. You will not get that through a linked model if it is faced based lighting or diffuser.

  3. I'm new to Revit and am going to have to implement MEP into an existing Architectural model. I was wondering how to design my own Mechanical and Plumbing equipment, establish it into a new family, and incorporate it into the model. Any help is appreciated.

  4. Im building a face based electrical outlet to master the revit content building techniques. One problem I am having a great deal of trouble with, is getting my 2d symbol to appear in my plan view when instered into a model. I started by building my annotation 2d symbol, with a label. Then built out my 3d family. when I nested my 2d symbol, it looke djst like the "out of the box" duplex recepticle that comes with Revit MEP, but the 2d symbol would not appear in the plan view!! (All model views appeared normally, and when I loaded my 2d symbol into the "out of the box" family, and loaded it - my symbol appeared - so I know that aspect is ok. Missing something in the 3D model family)

  5. When creating this electrical 2D symbology, you need to create it using the generic annotation template. This way it will scale with the drawing scale. (Use the generic annotation family template Autodesk provides with Revit)

    Then, that generic annotation symbol needs to be loaded into the model family as a nested family.

  6. A ceiling-based lighting fixture will cut the ceiling that it is hosted by. But how do you get a face-based fixture to cut the ceiling grid it is placed on?

  7. We are building Lighting Families for several major manufactures and need some feedback from both architects and engineers. Roughly, 50% of the Families currently available from lighting manufactures contain Electrical Connectors. For architects these Parameters are useless, but for engineers they save time if set up properly. Since ceiling grids and lights usually move around a lot during the design process, maybe it would more valuable to keep these Families separate forcing Manufacturers to offer a Symbol/ Electrical based Families for Engineers and Solid/ Photometric based Families for Architects.Another missed opportunity is regarding Catalogs. Most Lights have an Alpha Numeric Order number correlating to all the options available for that fixture. This translates into over a thousand Family Types for most commercial fixtures. By offering every possible order number minus multiple options, would this not help manufactures with orders for large projects? It only takes second to filter out a Light from a Catalog of thousands.

  8. One more thing to add to Scott's comment is that if the family category also affects if the 2D symbol shows up in plan view. e.g. Mechanical equipment category vs light fixture category...

  9. I am new to Revit & planning to draw the same Containment Layout which i have created in AutoCAD 3D. How can i make new contents like Ladder racks & Cable Baskets in Revit? Any help would be highly appreciated.

  10. How do you host recessed in-grade fixture into a floor ramp? and How do you adjust the VG to show in the RCP and not in Plan View.