The use of ‘ni wa’ and ‘de wa’

When identifying the location of an object, I can use 'ni' but is there a difference when I add a 'wa' after it?

e.g. 私の家の一階には台所がある。
And　私の家の一階に台所がある。

What is the difference between the two sentences if there is one?

Thanks.

This "wa" is often used to make contrasts. So while the one without "wa" simply says "There is kitchen on the ground floor of my house," with no context at all, the one with "wa" suggests something like on the GROUND floor there is the kitchen, and that you might go on to say "on the SECOND floor there is... thereby making a contrast between the ground and the second (or any other) floor.