In Chapter 8 of Alan Bell's book ... From the Director's Chair, Bell describes the pressure to bring the Getting Sam Home project in on time and on budget or preferably early and under budget, after he had won the bid for it based on a nearly unrealistic time and budget estimate, so "In the script, there was only one short scene to be filmed in the café, and it wasn’t worth the expense of building the set in the studio. Instead, I decided to film it inside the Ironmonger’s paint store. This meant that we would have to make the interior of the paint store look exactly like the well-known café set that was seen in the studio. There wasn’t much room for the camera and our lights, but the scene was static and didn’t need much room."
I have the eBook version of this book, so it's a lot easier too verify this kind of thing, as long as I choose the right keyword to search on.