Will my loft conversion need Planning Permission?

It depends on the design of your loft conversion you proposed to undertake. There are many designs that do not require planning permission and that can be built under the Permitted Development Regulations introduced on the 1st October 2008 and these can be viewed by the link provided on this site. However there are certain circumstances where planning permission is still required like the following:

Your house is a listed building
You live in a conservation area
You want to build dormers that face onto the road
You want to build a dormer that will look over a neighbour’s property
Any part of the conversion will be higher than the existing roof

If your home has already been extended to the limit of its permitted development (15% of its original size)

It is always advisable to discuss this with your local planning authority or specialised loft designers.