It appears most of the public are completely unaware of a recent change to the insulation requirements when carrying out external wall repairs or renewal on rendering.

The updated Building Regs require Building Control permission for a homeowner who wishes to alter, renew or remove at least 25% of an existing exterior wall coating.

For any alteration over 25% the legal obligation is to now ensure the walls have sufficient insulation to meet the lower U value requirements to cut emissions.

In a lot of cases for solid wall properties this means fitting an external insulation system as part of the replacement pebbledash,stucco or render system.

The really good news is that the extra cost this involves is usually paid back within 5 years in the form of lower heating bills.

Another benefit for insulating a solid wall property is a carbon saving of one ton per square metre of insulation eg a 3 bed semi would save around 80 to 90 tonnes of carbon over the lifetime of the insulation.

For further info see where energy and cost savings can be viewed by property type.