Just bought a plot - How long is it good for?

[Maxsdad]

there is currently no time limit on how long you can take to build a house. Time limits will come with 3.1. When it is implemented it'll be 45 days. So you have until Christmas day if 3.1 drops on schedule.

I know you have to ENTER your house to reset the clock and avoid foreclosure, but do you have to build one within that 45 days?