Insulation – for the Roof – for Walls – for Windows

In the average British building (business or home) 25-75% of the heat put into the property is quickly lost through the roof, walls and floors.

This is a complete waste that can be almost totally eradicated. I can talk sensibly about windows too but I am not a double glazing salesman!

Through the roof

There is almost no such thing as too much insulation – in your loft that is – I recently had too much insulation delivered and it clogged up my shed for months until I off-loaded it on Aberdeenshire Freecycle  which is great system where you can get rid of your unwanted items to someone who needs them without recourse to the landfill!!!!

About 20% of the heating energy use can be saved by installing good loft insulation, that is 150mm (6 inches in old money!) minimum and more if possible using glass fibre or sheep’s wool or blown recycled newspaper or whatever you can get your hands on.  This is truly not rocket science.  Really high quality loft insulation is available from all DIY stores and the fibre-glass stuff even comes now with plastic wrapping to avoid damaging your hands.

In an ideal world you can go “green” and insulate your loft with sheep’s wool – considerably more expensive than rockwool but almost carbon neutral and it lasts a lot longer too, up to 50 years. 

Wool can rapidly absorb and release moisture and so helps keep buildings cool in summer as well as warm in winter.  There are some concerns about harbouring pests and also potentially putting bats at risk but I am not sure how credible these stories are – if you have any useful information on the subject please drop me a line.

A typical house has a loft space of around 70m2 and insulation will cost you anything from £3/m2 for basic fibre glass up to £10/m2 for max thickness wool products.

So you are looking at spending up to £700 to lag the entire loft space.  This measure will save you 15-20% on your energy bills so you can do the math pretty easily to work out payback. 

I reckon 3 – 5 years payback in most houses with standard products.  Get in touch if you have any queries or would like to obtain details of what and where to buy.

Through the Walls

The outer envelope of a building can make a substantial contribution to reducing the amount of energy it uses through good thermal performance and air-tightness levels.  Recent developments have also seen incorporation of photovoltaic technology into building facades so the walls generate electricity.

When it comes to retrofit of this type of insulation there are two options – Internal and External.  Bearing in mind that internal wall insulation by necessity reduces the size of the room most companies these days look to external wall insulation – EWI – as shown on this community hall in Scotland for example – totally in-keeping, massive improvement in heat retention.  The entire building cost around £30,000 to complete which offered decent payback and EWI is a Green Deal measure and may also be covered by ECO so can be an attractive investment.  Talk to me if you want to develop the idea further.

Kilry 1


Now I am not going to sell double glazing so please don’t worry although there is absolutely nothing wrong with double glazing and it should be fitted whenever and wherever possible to provide good thermal performance and security to any property.  However, double glazing is not cheap and in many cases not appropriate for structural, architectural, planning reasons and so on.  So what do you do if you find yourself in a traditional building for example with 4mm single glazing in hardwood frames but you want to reduce your heat losses?

Glaze’n’Save is a good place to start – a great system of magnetic secondary glazing that cuts to U-value of a single glazed unit from 5.5 to 2.7 offering a 50% reduction in heat loss.


I love this stuff – it is dead simple to iinstall and can be taken down in summer to allow opening sections to be used normally – and it is about half the price or standard secondary glazing.

Give me a call if you want some more information.

Radiators & Pipes