Bay Windows - True Bay Windows cannot be created in Revit or can they?

[robinhill833400]

This refers to a true bay window and not an oriel or bow window such as those available out of the box.
The true bay window projects from the main wall of a building and has a wall below the window following the line of the window which usually is angled,
with the floor extending into the bay. This type of bay window wraps around three sides without masonry piers at the corners (that is another type of bay which is easier to create).

Trying to create a family for the window to insert in the main wall creates problems when inserting the low wall under the window..it simply won't join correctly without error, irrespective of using an opening or void.
It also does not recognise the area of the bay when creating rooms

Trying alternatively to create the bay by carrying the wall around the bay also doesnt seem to work, throwing up all sorts of problems unless there are brick piers at the angle corners ( which is not the type of window considered here).
Using a stacked wall with an upper thin wall zone in which the window elements can be inserted as families doesnt work as there are then conflicts in how that joins to the main walls

Whatever strategy to create these I adopt there always seems to be one last issue that revit doesnt like
I've read what seem like hundreds of posts on bay windows, but never yet seen a method that genuinely works for true bay windows.

Given that much of the housing stock in the UK has true bay windows, and planners often require them to be replicated in new work, we need a method to draw them. I assume this is likely to be an issue elsewhere too.

Has anybody truly succeded in creating true bay windows? If so can you please post your method or suggestions?

Thanks
Robin

[Mike L Sealander]

I'm not sure why you are having trouble with "carrying the wall around the bay", which is the method I have used. Are you saying you don't want to see any wall at all when cutting horizontally through the window? The easiest method may be to use a curtainwall for the window, and create a custom mullion for the angled connections between window frames.

[robinhill833400]

The issue with that method seems to be mainly the junction back to the main wall, in that the reveal is usually square to the main wall, but the angled wall tries to cut it off and run through.
Also because of the number of projects that need this I was hoping to create a window family that could shedule with other families.
I dont want to see the main wall run through in plan or section except above the window head.

Were you able to create a family for this method or do you create this in the project each time?

[Alfredo Medina]

It should be possible to create a parametric bay window that displays correctly in all views. Probably you need to erase the opening and replace it with a void, to create the angled cut in the host wall. To comply with other requirements that you mentioned above, such as room bounding, some work would be required in the project after the insertion of the window, like a split in the host wall, to allow the room to get inside the projection of the bay window, if the window has a parapet.

[robinhill833400]

Good idea about splitting the host wall to allow the room in...I shall try that.
Ive tried using a void instead of the opening, that seems to work, but seem to have problems with with 2d line work quickly starting to overconstrain it...Can you have a look at the family I posted in the Revit Family forum? I did this from scratch without 3d elements trying to find what keeps going wrong, and it seems to be something to do with constraints.

[Alfredo Medina]

I took a quick look at that family that you posted, and I was surprised to see so many reference lines and constraints. The more you put, the more things can go wrong. The idea with "bones" if that we trace the main skeleton of the forms, not that we draw also the edges with reference lines. The edges can be related to one main reference line with offset values and fixed distances.

[robinhill833400]

Thanks Alfredo...I shall try that again...tho last time I tried the sill and glass lines didn't follow when flexed, maybe that was due to a different issue because that time I had tried to build geometry at the same time as creating references.
Robin

[robinhill833400]

Bay Window 2 Oct12.rfa
Well I have followed Alfredo's advice and rebuilt it from the ground up with minimal reference planes and reference lines,
and it sort of works in 2d plan so far, here it is.

Some behaviour puzzles me though...
try inserting it in a wall and then changing angle to 60 degrees, and window depth to 470. It works.
Then try reducing the window depth to 468, and it fails at that angle.

Geometrically I cannot see any reason for it to fail with that combination of data.

This occurs at other combinations of angle and window depth, where if the window depth is too small it fails.
Can anyone see why?

Thanks for the help so far, and hope someone can shed light on this behaviour.
Robin

[Alfredo Medina]

I did the test that you described, and the 2d window worked correctly (Revit 2013 OneBox).