It is down in the PP documents as Engine house.
View attachment 79737
To be fair it isn't as explicit as it is in other parts where it says it will be used as a cafe and museum. Hard to remember where I read that though when you trawl through pdf after pdf.
In this document it says its use may include, but hopefully it will give you a flavour.
Can just imagine quite large optics all attached to the exterior of that Pumphouse, all free and every lager / beer of your choice, self service hmmm.