Planning permission - Liverpool City Council Planning and building control Planning permission Do I need planning permission? There are different planning consents and approvals you may need to get before starting any work on your project. Planning permission for HMOs All houses of multiple occupancy (HMO) for seven or more people must have planning permission. In 11 Wards, permission is also needed for HMOs for three or more people. Permitted development Permitted development means you don't need to apply for planning permission for many common householder projects. Article 4 directions Works that change the external appearance of a building in a conservation area will need permission if subject to an Article 4 direction. Retrospective planning permission If you've built without permission and committed a planning breach, you'll need to submit a retrospective planning application. Planning advice notes We've produced some advice notes on a range of planning topics which you may find useful. Lawful development certificate A legal document stating that enforcement action cannot be carried out to the development referred to in the certificate. Related pages Biodiversity net gain (BNG) Inclusive design