TOPIC:

To select the roof, you must have the layer that the roof is on as the current active layer. If you are not sure which layer that is, toggle each layer off/off until the roof disappears and then make that the active layer. (Ctrl + Click the layer) In which case your roof was on Extended Bedroom - Floor Plan. You can now select the roof.

To investigate ant strang blocks, do the same until you discover which layer they are on. One block is on the Plant room / New Utility - Linen store - Floor Plan.
With this as the active layer, you can double click the block object and a dialogue will activate: Roof panelling. This is possibly left over from a past edit, but you dont really need to see the roof panelling, so you can switch it off in the Visibility tab for the 3D view. Roof Panelling is in the Extension Elements sub tree in the Visibility dialog.

Hi,

I am having some difficulty adding a roof - or more accurately two roofs - to my model, where the roofs need to span several buildings. My first attempt, (jpeg and project attached), raises two questions.

Why can't I select the roof with a double click, to adjust the height, change the hips to gables, reduce the overhang etc?

What are the grey block shapes extending into the sky from two of the rooms, as a result of adding the first roof?