Copy+Paste part of the project to another file?

[Andrash]

I created 3D project of the apartment. The next step is to design kitchen furniture, all the units, boxes and play with the different layouts/measures etc. While rotating and zooming the model other rooms' walls are often getting in the way and distract me from the kitchen. What is the easy way to copy just part of the model that contains only one room (the kitchen) and paste it in a separate file for better focused layout designing?

Or am I probably thinking the hard way and using Sections/Cuts in the same file is more elegant?

[Dave R]

There are several ways you could handle this. You could use layer and turn off those layers you don't want to see. This get components such as walls and other parts of the structure out of the way while you work on the kitchen. You could also use Section cuts.

If you really want to work in a different file, you can select the walls and other things you'll need to be able to layout the kitchen, use Edit>Copy or the appropriate keyboard shortcut keys for the OS to copy it to the clipboard. Then go to a new, blank SketchUp file and use Edit>Paste in Place. This will put the selection in the same position relative to the origin as in the original model.

After you've got your kitchen furniture and appliances in place, select them, copy them and use Edit>Paste in Place again to place them in the original file.

[Box]

It's very possible that the thumbs down on Dave's post is from my fat thumb, it happens to correspond with with were I scroll when reading on my phone. As I'm unable to give it a thumbs up it would seem to be my fault.
So having come clean about that I just like to add....
It can be helpful with some models to create separate files for individual parts and combine them in one grand plan model.
So you create the different rooms of your apartment as components, using the copy/paste in place method described by Dave. This lets you work on them in detail without the rest of the model getting in the way and you can reload them into the complete model when needed. Handy when you think of it as the full model being a city and the components each house.
Combining that with layers and section planes and anything is possible.