If you are intending to lay or replace a hard surface to the front of your house you must use permeable or porous materials; alternatively surface water run-off from an impermeable hard surface, such as concrete, must be directed to a permeable or porous surface to the front of your home.
You can replace or repair a small area of up to 5 square metres of existing hardsurfacing without using permeable or porous materials - for example to repair pot holes in a driveway, or replace paving slabs in an existing patio.
Significant works of embanking or terracing to support a hard surface might need a planning application.
If you live in a listed building, you may need listed building consent for any significant works whether internal or external.
Removal of permitted development rights
You need to be aware of whether the permitted development rights have been removed from your property by the Local Planning Authority. If they have been removed, you must submit a planning application for the work.
The Local Planning Authority may have removed some of your permitted development rights as a condition of the original planning permission for your property. This information will be available on the planning register held by the Local Planning Authority. Permitted development rights may also have been removed by an 'Article 4' direction. These are most common in conservation areas where the character of an area could be threatened by unmanaged development. Your solicitor should have informed you of whether an article 4 direction exists when you purchased your property, but you can check with the Local Planning Authority if you are not sure,
Householder guide
The Welsh Government has produced a technical guide, and a householder guide, available here, to help you understand how permitted development rules might apply to your circumstances.