My reading of the scenario is that it is a complete rebuild (and extension) which involves creating multiple layers of a new deep substrate. Resurfacing is a different, and relatively simple, task ...
... unless, as happened at Scampton in the 80s, the contractors didn't bother with the friction course as they were running out of time/money. Day One of ops on the new surface, on a rainy day, revealed a skating rink. "Stand down Scampton Wing."
