What Constitutes Urban Sprawl?

[Kokkei Mizu]

I'm asking this because there's a development near my house (which is already an urban sprawl type of neighbourhood built in the 50's) where they are building one street with about 30 homes where one house used to sit. The land wasn't a farm, just one house with a big property.

Would you consider this infill or urban sprawl, or both?

Here's a map of where it is in relation to St. Thomas and London.

http://goo.gl/maps/vhjP