Insulation Back to Blog



If you are installing new insulation, you do not need to seek planning permission in most instances. You do need to consult with your Local Planning Authority however, if your building is listed or within a conservation area. Insulation has to comply with relevant building regulations which cover the minimum energy efficiency requirement and thermal insulation. These regulations are covered in building regulation Approved Documents.


Any installation of loft insulation must meet strict minimum energy efficiency standards. When insulation is sold it has an energy efficiency rating that must comply with your relevant regulations. If an upgrade cannot meet the current minimum energy efficiency rating, then the insulation should be upgraded to the best standard achieved within the past 15 years.

In the case of roof renovation projects, if more than 25% of a roof is being repaired, replaced or maintained, the level of insulation needs to meet the standard in your building regulation Approved Documents.

Cavity Wall

In almost all circumstances you will need to submit a building notice to a building body control in your local area notifying them that wall cavity insulation work is to be carried out. This applies to all buildings that are not exempt from building regulations. The installation of cavity wall insulation is defined in the building regulations as notifiable building work.

Solid wall

This follows the same rules as loft insulation, which means that you do not typically require planning permission to move the project forward. Solid walls must meet the minimum energy efficiency standards and if that is not achievable, then solid wall insulation must match the best rating achieved over the past 15 years. If 25% or more of an external solid wall is being renovated, then normal building regulations apply and thermal wall insulation must meet the regulations set forth by Approved Documents.


Floor insulation follows the same rules as loft insulation and solid wall insulation.


For more information on insulation, please visit The Planning Portal.


The information contained within this article is strictly for guidance only.  Cost2Build recommends that you always check current sources of information in case regulations have changed. Cost2Build cannot accept any liability for miscommunication of the law in the case of a change in regulation or any action done to a property based on the information held in this article.

Leave a reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> 
<del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>