Regency Terrace Modules RTM SCFP1 Stone-Clad Fascia and Porch
The most elaborate item in the series, this is the piece that enables most of the terrace variations. It's double sided, and can also be set to varying heights - there are more steps beneath nominal 'ground-level', and you can raise it to + .40 without encroaching on the first floor windows. You can also slide it in and out to give varying depth: at the nominal height, for example, it's possible to push it back far enough to form a porch over the existing main unit door.
Commonly seen as a decorative addition to the ground floor of such buildings, whether the rest of the construction is of stone or brick.
The foreground of the screenshot shows both faces at the pre-set height.