TOPIC:

Could you email the project both pre and post roof merge so that I can see the problem. I do have an earlier project of yours but you don't appear to have separate roof sections in that earlier version.

Its not clear in the photo of 4/11 ( see topic ) the actual pitch and ridge connection. Do you have the pitch of each section and the ridge height?

I confirm that I did solve the merging of the lower level annexe roof and the main roof.

However I am still struggling with the merging of the roof of the bay window with the main roof. Superficially it merges OK, but (the devil is in the details) it always misses out one of the rafters at the intersection of the two roofs. See image below...

Ah Ha!!

Brilliant!! Thank you..

Although merged you can continue to edit the rear roof, and so reduce its height by 0.26m.

Thank you for your efforts. But sorry to say, but I think we are going in circles...

You have redrawn the rear roof on the same height as the front roof. The whole point of my OP is that the rear building roof height is 26 cm lower than the front roof height. This is the reason why I have two buildings rather than one. Otherwise I would have simply drawn both parts of the house in one building!

So let me once more rephrase the question: How can I create two roofs on different heights, and then merge them together?

I redrew the rear building roof, but on the front building layer. This allowed me to then merge the roofs.

Then of course I deleted the original rear building roof.

I have emailed the resulting project back to you.