The blue plaque on this wall records this building as Isambard Kingdom Brunel's site office at Chippenham station. I'm not sure how much time he would have spent here as he had resident engineers and contractors actually building the Great Western Railway. It was later used as a refreshment room for passengers and this side may have been rebuilt to match the station - the other side of the building is of much rougher stone.
<a href="//commons.wikimedia.org/wiki/User:Geof_Sheppard" title="User:Geof Sheppard">Geof Sheppard</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>