When working in Autodesk Revit for MEP Electrical Design, lighting fixtures can be either hosted (such as ceiling-hosted or wall-hosted) or non-hosted. The movement of lighting fixtures in relation to linked model elements—like ceiling grids—is determined by the hosting condition and alignment constraints applied to those elements.
According to the Revit MEP User’s Guide (Chapter 24 “Ceilings” and Chapter 50 “Rendering”), a ceiling is a level-based element. You can create it on a specified level and host ceiling-based families such as lighting fixtures. When a ceiling is modified or repositioned, the hosted lighting fixtures will move with the ceiling itself, maintaining their relationship to the host surface. However, when ceiling grid patterns are changed or moved in a linked Revit model, the movement of those grid patterns does not automatically propagate to hosted elements in the electrical model unless those elements are directly linked or constrained to a movable reference plane.
As described:
“Ceilings are level-based elements… When you create a ceiling, you can host components such as lighting fixtures on its face. Hosted elements remain associated with their host even if the ceiling is modified.”
And further in the glossary section:
“Rehost: To move a component from one host to another. For example, you can use the Pick New Host tool to move a window from one wall to another wall.”
This confirms that a hosted light fixture maintains its attachment to the host element (the ceiling) but not to the grid pattern itself. Grid movement within a linked ceiling model does not alter the position of lights unless they are manually re-hosted or alignment-locked directly to a specific geometry within the host model.
Therefore, the correct interpretation is that when ceiling grid patterns move within a linked Revit model, the lights placed in the electrical model do not follow the grid pattern movement automatically. They remain stationary relative to the ceiling surface, provided they are hosted correctly.
This behavior reflects Revit’s parametric relationships — “hosted elements maintain dependency only on their host, not on graphical references like grids unless locked via constraints.”
[References:, Autodesk Revit MEP User’s Guide, Chapter 24 “Ceilings”, pp. 579–583, Autodesk Revit MEP User’s Guide, Chapter 50 “Rendering” (Lighting Fixtures and Hosts), Autodesk Revit Glossary: “Rehost” definition, p. 2037, Revit Electrical Design Parametric Model Behavior – Revit MEP Essentials, ]