Roof by Footprint - Selcting a Core Boundary

[jcam]

I have had Revit for a number of years but have never really sat down to use it properly. I am now trying to use it for all my building design work and trying to get away from AutoCAD.

I would appreciate if anyone could tell me if there is a way to select a core boundary for Roof by Footprint. I have found that by selecting the Pick Walls option with an overhang, the wall overhang is measured off the external cladding. The trusses are set up in the project I am currently working on so that the underside of the bottom chord sitting on the packing /ribbon plate. The springing line is at the outside edge of the timber studs. I understand that the base offset can be lifted up and down as required. If I need to change the wall cladding on individual walls from brick to block or to timber cladding or anything really, the overhang that is applied using Roof by Footprint alters the geometry of the roof. I can fiddle with adjusting base offset and overhang each time a wall cladding is changed but it would be nice to select the Core boundary (ie the outside edge of the studs) and have the overhang applied to that line<script id="gpt-impl-0.2755483820632518" src="https://securepubads.g.doubleclick.net/gpt/pubads_impl_139.js"></script> rather than the outside of the wall cladding.

I have attached a sketch to help I hope.

Any suggestions would be much appreciated.

[Duncan Lithgow]

Hi jcam

I'm not aware of any way to If you use Pick lines (perhaps with an offset) you will be able to lock your distance from which ever edge/boundary of the wall you want. If you do this in the model the whole roof will follow that edge, but if you do it inside the sketch only that edge of the roof will follow your changes.

However, be careful with locking things, especially in sketches. It's not obvious to any other users what you have done. And with complex roof footprints it can throw some strange errors which can be hard to resolve. Those are perhaps not such problems in a smaller project with a small team - but it's worth keeping in mind.

[jcam]

Hi Duncan

Thanks very much for your response. I will give the method you describe a try.

[PijPiwo]

When picking the walls, make sure ‘extend to wall core’ is checked (options bar). That will lock the roof to the wall core - changing any wall layers other than the core, will not affect the roof.

[jcam]

Hi PijPiwo

Thank for the tip. I will make sure I do that.

PS Duncan - I have tried your method and it works a treat.