There is no single legal definition of "habitable room", as its use and meaning are subject to context. Generally, a habitable room is a space in a building that is designed for people to live, sleep, or spend extended periods of time in, but does not include bath or toilet facilities, corridors or utility rooms.

In most cases, yes - planning permission is required to operate a business from your garage. This is because the use would no longer be purely domestic, and the garage would be considered to have changed use from residential (Class C3) to a business-related use, which requires planning consent.

Planning permission is unlikely to be required for the installation of external damp proofing unless the work will change the external appearance of the building or is part of a larger project.

If you live in a listed building you will need listed building consent for any significant changes, this can include external damp proofing. Additional rules may also apply if you live in a Conservation Area or other protected area.

Building regulations approval is not required for installing an external damp proof course (DPC).

Read further guidance on damp proofing.

It is likely that you will require planning permission to extend an existing front porch to add a toilet.

Adding a porch falls within permitted development rights meaning an application for planning permission is not required provided specified limits and conditions are met. However, to fall under permitted development rights for a porch, the total ground area must not exceed three square metres. This is unlikely to be enough room to fit toilet and the required additional components.

Read the full rules for porches under permitted development on our mini guides.

If your porch exceeds these limits, it will be classified as an extension. These can be permitted development but come with a different set of rules.

Extensions are not permitted development if they are built forward of the ‘principal elevation’ of the house. As such, you will be required to submit an application for planning permission to your local planning authority.

If you live in a listed building, you will need listed building consent for any significant changes.

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Your gas meter should only be moved by your energy supplier or your local gas network operator. For more information contact your energy supplier to understand if they can move it based on your requirements.

Full details on gas safety and planning can be found on our utilities common project.

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