Is residential area nominal or ordinal?

Answer 1

Without more information it's difficult to be sure. It sounds like a nominal data item. As an example, in the city of Hamilton, Ontario, Canada, residential area could be coded with the names that include:

Westdale

West Hamilton

Durand

Buchanan

Kirkendall South

Balfour

and so on. Unless a series of residential areas are ordered along a lakefront or seafront or some other two-dimensional feature they cannot form an ordinal scale. If they are spread over a two-dimensional area they cannot be put in what is called a mathematical linear ordering which is what is required for an ordinal scale.