An assessment will need to take place to see if the loft is suitable for a conversion. An architectural designer will look at the height, roof pitch, and footprint of the roof area. Based on the dimensions, they will design and draw out proposed floor plans and elevations to visualise how the room can be used, whether being a bedroom with en-suite or an alternative room for the house such as an office, playroom etc. 

Loft Conversion Types

There are a few ways to maximise the space within the loft and get the most of natural light. Here are some of the ways you can do this:

  • Roof Light
  • Single Dormer
  • Full Width Dormer
  • Side Dormer
  • Hip-to-Gable
  • L-Shape Dormer
  • Mansard 
  • Pre Fabricated 


Planning Permission

A loft conversion itself does not require planning permission, unless there is a restrictive historic condition preventing such conversions without applying to the local council. 


Under permitted development, you can erect dormers and roof lights to the loft conversion, subject to limitations. If the loft conversion alters the roof form in any shape, then this would be considered ‘development’ and therefore is subject to planning control. 


Although planning permission may not be required, it is advisable to obtain a Certificate of Lawfulness, which is a formal document from the council stating that it is permitted development.  This can help with at the time of a selling a home as solicitors will carry out checks to the house to see if everything has been built lawfully, compliant to planning control.

Although planning permission may not be required, it is advisable to obtain a Certificate of Lawfulness

Building Regulations

A loft conversion is subject to approval from Building Control. The architectural designer and structural engineer will look at the build of the proposed conversion checking the structural strength, the stability of the new loft, a fire escape, stairs to the loft, and insulation.

Party Wall

A party wall agreement may be required where your house is semi-detached or terraced as the loft will adjoin a neighbouring property. The agreement can cost around £800-£1000, however if you are able to get your neighbour to sign a waiver, you may be able to alleviate this cost. 


The cost of the loft conversion is based on the room type, design and materials. To complete the planning and design of the proposed loft conversion it usually costs around £1,6000. If it requires any structural calculations or advice, then this can cost around £500.