There are two dictionary definitions of a town house.
Per the Collins Dictionary:
- A town house is a tall narrow house in a town or city, usually in a row of similar houses, which are connected together.
- The town house of a wealthy person is the house that they own in a town or city, rather than another house that they own in the country.
The second definition is the one that describes Spencer House.
It’s actually an end-of-terrace house built in stone on a grand scale. Indeed, it has even been described as an aristocratic palace.