It was meant as an addendum. I might have confused it with the chancery house on the other side of the road, streetview footage shows construction signs for a coworking space so I assumed it would be that.
The actual address seems to be from a law firm, not sure how good of a sign that is.
It's not unusual for UK companies to use their solicitor's address
(not affiliated but feels a bit rough as a critique for a companty that has shipped keyboards for a while)