New regulations came into force on 30 September 2013 which changed the building work which can be done without needing to apply for planning permission. 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.
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.
Disclaimer - Wales
This is an introductory guide and is not a definitive source of legal information. This guidance relates to the planning regime for Wales. Policy in England may differ. If in doubt contact your Local Planning Authority.