Installing WP on existing website on GoDaddy

Is it safe to install WP into a new directory in the root of an existing WP website for design purposes and then move the site to the root when the design is ready?

It is a restaurant’s website which needs to remain live for business, so I am planning on building the new website ‘offline’ in a new directory and then moving it to the root when the design is done.

Not sure what is best practice in this circumstance?
Is it problematic moving the website then from this folder to the root?
There is not a huge database – it is simply a companies website.

I have read quite a few answers hear and it seems less problematic to change directories than to change servers.