You can make an application for Planning Permission through the Planning Portal.
If your property is in a conservation area, your application will need to include a Heritage Statement setting out what work you are looking to undertake, what the effect of that work is on the conservation area and how you have tried to reduce any negative impact arising from that work.
Please provide as much information as possible, including photographs where possible, as this will help us understand what you want to achieve and how you will go about it. A clear and comprehensive heritage statement will avoid the need for follow-up question and will help ensure we process your application as quickly as possible.