6. External Wall Insulation

Putting insulation on the outside of your house – you need to know your stuff.

◻︎   Yes, this is really an option to be considered however it is essential that you get trade or professional advice.

◻︎   There is plenty of information on the Energy Saving Trust website including technical guidance.

◻︎   This is a highly technical as well as skilled process and you will need to do your homework. Check that contractors are currently registered with the relevant trade bodies such as INCA, their work is covered by an insurance-backed guarantee, and that the contractor is on the product or system manufacturer’s approved list.

◻︎   By the way, do check current membership of trade bodies by contacting the bodies direct.

◻︎   Ignore flyers found on the doormat – however plausible!


Putting insulation on the exterior of your home


•Insulating the outside of a detached house may present fewer technical issues, but it may be the most costly. Make sure all the alterations and repairs to enable the insulation to be fitted are budgeted for and do get other options costed for comparison.
•The extra layer added to the outside will alter the appearance of the house at windows, the roof and at any architectural features. The finish will be different to what you have at the moment. Ensure you’ve got covered the construction detailing at air vents, roofs of ground floor extensions, etc.
•An early chat with your neighbours is a good idea, especially if the house is a semi or terraced. Also check if any estate covenants apply and establish if Planning or Conservation Area Consent is needed.
•Exterior insulation could be the way to go if part of a more general modernisation (or makeover) of the property. There are plenty of examples in this area of 40+ year old houses which have had this upgrade and aesthetic changes made.

Some general dos and don’ts


Breaking down and lumping together tasks. Try and tackle the work either in phases room-by-room (which makes it easier to control the work) or by lumping together work within a particular trade (to avoid return visits adding to costs).

Avoid taking risks (financial and safety) when selecting contractors and tradespeople. There is excellent advice on various websites including www.hants.gov.uk/tradingstandards  and the national directory www.buywithconfidence.gov.uk 

One of the best sites for further research is www.energysavingtrust.org.uk  Follow links to energy at home and reducing home heat loss.

The BRE publish a number of Good Building Guides which will be useful.