Cavity Wall Insulation for ASHP

Redlander

To get the government grant for an ASHP:

Your property must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation.

Our house does not have cavity wall insulation and I am planning to have it installed. What I am uncertain about is whether to extend the cavity wall insulation to our conservatory, which we only use for storage and never heat. The conservatory has one full height side wall and two glazed sides sitting on a brick "plinth".  I can see no practical benefit in fuel economy by insulating it, but I am wondering whether the EPC surveyor would nevertheless require it be done in order for us to get the maximum EPC rating.

Do I need to insulate the conservatory or not?

Reed_Richards

They have to make holes to inject the cavity wall filler and the presence of these holes would tell a skilled inspector whether a wall cavity has been insulated or not.  I'm not sure that EPC inspectors are generally all that skilled; maybe yours would not notice either way?  But will it cost much more to play safe and insulate the conservatory wall?  I'm afraid I don't know the answer to your fundamental question.    

Netexporter

The conservatory won't count as a habitable room, so I'm pretty sure you don't need to insulate it.

paul991

Think lots of cow boys in this industry after checking with thermal camera loads of cold spots in wall, A few years later  when looked at part of wall  not normally visible from my  property found loads of  holes not sealed

smallblueplanet

Redlander said:

To get the government grant for an ASHP:

Your property must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation.

Our house does not have cavity wall insulation and I am planning to have it installed. What I am uncertain about is whether to extend the cavity wall insulation to our conservatory, which we only use for storage and never heat. The conservatory has one full height side wall and two glazed sides sitting on a brick "plinth".  I can see no practical benefit in fuel economy by insulating it, but I am wondering whether the EPC surveyor would nevertheless require it be done in order for us to get the maximum EPC rating.

Do I need to insulate the conservatory or not?

"The eligibility rules to get a grant are changing. From early May 2024, your property will be eligible even if there are outstanding insulation recommendations on the EPC."

https://www.gov.uk/apply-boiler-upgrade-scheme/check-if-youre-eligible

"There are no minimum insulation requirements for applications which are properly made after 8 May 2024. 

If an application is properly made before 8 May 2024, you must provide an EPC with no recommendations for loft and cavity wall insulation. For more information, please refer to property owner guidance V2.5.

It is important that property owners understand that heat pumps perform best in a well-insulated property. 

Insulation measures, such as cavity wall and loft insulation, are relatively low-cost measures that could reduce energy bills and increase heat retention in a property. For example, without loft insulation, around a quarter of heat is lost through the roof. These types of insulation help to keep heat inside the home, making it more comfortable and lowering heating costs."

https://www.ofgem.gov.uk/environmental-and-social-schemes/boiler-upgrade-scheme-bus/property-owners

FreeBear

Netexporter said:

The conservatory won't count as a habitable room, so I'm pretty sure you don't need to insulate it.

And there should be an exterior grade door between the main house and the conservatory.