For a householder application 8 weeks is defined in legislation. Read more here. But this is hardly ever achieved. Allow at least 12 weeks. Many Councils take longer still. Depending on the efficiency of the officer handling your application, complexity of the development, and on overall workload of the planning office.
Applicants have an automatic right to appeal if a decision is not made within eight weeks. That’s an appeal to central government to make a decision instead. In practice if you threaten an appeal then a Council would probably refuse the application immediately. So most applicants accept the delay.
