How long does it take to process a building control application?
For an application by Building Notice, there are no detailed plans to inspect and approve so you can start work as soon as the notice is accepted - usually within 48 hours.
With a Full Plans application the plans have to be thoroughly examined before being approved. And by law a council must give a decision on an application within five weeks of receiving it (unless it's extended with your written consent), but usually it takes much less time than this.
Approval of building plans lasts for three years and if you don’t start work in that time your council may serve you with a notice declaring your plans to be “of no effect”– meaning you will need to submit a fresh application.