Adding Opening to Existing Roof

[GeorgieB82]

Hi All,

I keep stumbling over this time and time again; I do a lot of plans for loft conversions.

I have an existing roof which is being kept but the proposal is to add a box dormer. This will require cutting a hole in the existing roof. I can not find any way of doing this using the renovation filter. There are predefined objects such as skylights which create holes in roof structures and work with the renovation filters. Likewise I need to create openings in existing floors and ceilings (slabs) to add stairwells.

Could this functionality be added to create an empty opening feature for roofs and slabs? similar to the functionality currently provided for openings in walls.

Currently, I am copying the roof/slab to the new renovation and demolishing the exiting but this isn't correct as if I produce a demolition drawing the roof/slab will be shown which is incorrect.

[Anonymous]

You could create a new roof with the demolition contour for your existing roof. Then apply a SEO to cut the existent roof.
Hope this helps.

Edit: I suggested AC23 openings on the roof, but actually Openings can't be applied to roofs.

[Rob Hancox]

I’m having exactly the same dilemma; I’ve got a classic wrap around extension and loft conversion. The Renovation Palette is excellent for a before and after workflow, along with the demolition drawings and schedules, but when it comes to the loft conversion I have a major issue.
Of course I could use the Dormer Shed element but unfortunately the modifiers are not flexible enough to give you the window and facia options, they’re also a little clumsy.
A can model the loft conversion, of course, using all of the normal “trim to roof” and “solid elements” extrusion etc, and create exactly what the client/I’m happy with. But can I show this on the same structure as a “before and after”, I cannot.
So, has anyone got any neat ways of doing this with copying an entire building!

Thanks in advance.

Rob