One object out of several

Hello everyone, such a question. There are 2 separate objects: a wall and a window. Is it possible to combine them into one object? Not to group, but to combine it so that it is perceived as one whole: a wall with a window? Thank you in advance.

When it comes to the number of objects, MergeModel merges the number of objects into one

Thank you, Старик, I will try.