In most cases, you will not require permission to install a cloakroom suite, or any components such as downstairs toilets, provided you don’t need to make adjustments to your home’s exterior.
That said, it is still recommended to check with your local council before commencing with a potentially invasive project such as a downstairs toilet fitting or cloakroom suite installation.
If you need inspiration regarding some of the best cloakroom suites to consider for your home, take a look at our blog, Fabulous Downstairs Toilet Ideas.