Atleast 2 weeks minimum I'd say.
And I am sure they will not open servers earlier after the maintenance, like how they did last time when they increased the numbers of districts.

They wanted people to have plenty of time to enjoy the story instead of rushing through it just to secure a house.
And good luck with getting the house.
Most people (me included) will be parking our characters ready to buy houses when servers opens up after the maintentance.