Do Permitted Development Rights Apply for HMO Loft Conversions?

If you have an unused loft at your HMO that you’d like to rent to a tenant, you  may be wondering how easy is it to convert it into an extra bedroom? 

There are many potential benefits that come with converting a loft at your  HMO.  

  1. Increase your rental income by as much as 30% depending on the size of  the room. 
  2. Increase the overall value of your property in terms of commercial  valuation.  

For your tenants, a bonus is that by adding another room, many of their utility bills will reduce overall.  

But is planning permission required for a loft conversion in a HMO? And do permitted development rights apply? 


Permitted Development – An Overview 

Permitted development rights are the automatic granting of permission from the local authority when a property is going to undergo work or change its use.  Not all construction projects come under permitted development. It’s  important to ensure that any loft conversion that you plan fits into the limitations and conditions to avoid making an application for planning  permission.  


Dormer Loft Conversions 

In most cases, a dormer loft conversion will be deemed to be a permitted  development with no need to obtain planning permission. So long as your  HMO isn’t in a conservation area and you adhere to the permitted  development criteria, you should have no issues. Always check with your local  authority before commencing work though! 


The Specifications for Permitted Development 

Permitted development guidelines for loft conversions vary between councils, but there are some general rules that apply.  

  • The new space must be under 40 cubic meters if the property is terraced  or 50 cubic meters if the property is semi-detached or detached.
  • The conversion must not extend beyond the current roof slope’s plane to  the front of the property. 
  • The construction must use materials that are like those used for the  remainder of the property.  
  • The loft cannot extend beyond the building’s façade wall. 
  • Dormer extensions cannot be higher than the roof’s highest part.
  • A minimum of 20cm must be left for roof eaves surrounding the  dormer’s perimeter. 
  • Any side windows must be glazed with obscure glass.  
  • Any window under 1.7 meters from ground level cannot open.
  • The property must not be in a conservation area, national park, or world  heritage site.  

If your proposed HMO loft conversion meets all the above criteria, you should not need to worry about applying for planning permission. Always check with  your local authorities before beginning work.  

If you’re converting a loft to create an extra bedroom and are looking for  suitable tenants, don’t hesitate to get in touch with the experienced team at Portus Lets Ltd on 0151 329 3538 or email We are your local HMO property management experts in Liverpool and can help  you with all aspects of managing your HMO property. 

Stay In The Loop

Sign up to our newsletter.

This field is for validation purposes and should be left unchanged.
  • Unit N, Baltic Creative,
  • 49 Jamaica Street,
  • Liverpool,
  • L1 0AH
Opening Hours

Our normal office hours are:

  • Monday - Friday - 09:00-18:00
  • Saturday - 10:00-16:00
  • Sunday – Closed