By Dennis Collin
Revit is an excellent piece of software that ensures consistency of data throughout a project. However, sometimes it is too good! This consistency can work against you, for example, because it is all too easy to move a survey base drawing, the survey point or structural grids and levels accidently losing coordination with site models, resulting in lost time fixing these accidental changes.
For some years now, we have some controls to stop such calamitous events from happening. These controls are apparent either as little buttons in the bottom right hand corner of the screen, or as a drop-down menu on the Select panel of the ribbon interface.
Sections that are unticked or marked with a red cross are un-selectable for editing purposes, but can still be referenced for measurements, dimensions and object snaps.
The ability to not accidently move a linked survey drawing or model is obvious as they are usually a base drawing to which the Revit model connects to the real world. Revit being a model-based program is consistent, so if the model moves in one view, it moves everywhere! It is generally considered good practice therefore, to enable this lock once the model has been coordinated and positioned to ensure it remains correct.
Underlay elements are very useful to show a combined ceiling and floor plan, looking in two directions at once beyond the standard view range, or referring to the level below or above in a coordination drawing. Underlay elements are objects that are associated with another level, but need to be shown, usually half-tone for coordination purposes. If they are visible, then elements can be graphically selected, moved or deleted, which is often unexpected and is not immediately noticed at the time of editing. Typical examples are drawings showing supporting beams under floors, or underfloor pipework and services. I would recommend preventing the selection of underlay elements as a default.
The pin function has been in Revit for many years and is mainly a user definable tool to lock elements down like grids, levels and reference drawings. It is useful to lock down the survey and project base point (as well as turning them off) to prevent the accidental change of coordinates. Having set pinned elements as un-selectable gives an extra layer of security, meaning that editing a pinned object is more deliberate. Some objects are automatically pinned by the software including the arrayed beams within structural beam systems and railings, but these can be modified according to project requirements. I would advise anyone working on a project and encountering a pinned object to talk to their project lead or a colleague before altering it.
Select elements by face I don’t use too much personally, although it can be handy when using the paint tool for surface finish drawings. However, I normally disable this function, but it is down to individual preference.
Drag elements on selection, in my opinion tends to lead to undesired changes, so normally I disable this function. If one needs to move an object, I’ll use the dedicated move command or appropriate shortcut keys.
The final button which is missing from the dropdown is a selection filter function. When objects are selected with a window type, sometimes undesired or unexpected objects get selected. For example, a user selects some walls grabbing some doors in the process. This command would let you keep the walls selected, but drop the doors and any other undesired items.
Whilst these methods are useful in projects large and small, users do also have another method to prevent undesired changes in a Revit model. This is the use of Worksets which I shall cover in another blog.