There are different rules for tenders by public bodies depending on the likely cost, and a project such as demolishing Burlington House would likely have to go to The European Journal, but there is only one demolition project in Dover on there that was issued on 24/12/2014, and
details are only available to subscribers.
(It's not necessarily the cheapest that is the best and has to be accepted).
However, I think I recall it is the developers not DDC who issued the tender and will be paying the bill, in which case it won't be this one.