lagging does it pay for itself?

My wife recently decided it was time to paint our house, between her and the decorators she has done an amazing job making the house looks new again. My wife likes laminate flooring, I like carpet, now we have laminate.

Our house was built by an idiot in 1922, we have wooden floors above a vented cavity, open to the elements. This was done to make sure the occupants were not killed by carbon monoxide poisoning from the open fireplaces, it also makes sure that the house is never warm. Vented floors are a disaster from a previous age. In the US of A for the last 20 years they have been filling the underfloor cavity with cavity wall insulation to get rid of the drafts now no one uses the fireplaces. They drill a huge hole in the wall below the floor boards and pump the lagging in, its a brilliant idea. We have yet to catch on to this idea here in the UK If you ask anyone in lagging land to do this they all shit their pants and tell you the house will fall down 10 minutes after the lagging is put in.

So because I couldn't get anyone to fill the cavity up we went for overlay insulation. I insisted we put some lagging down on the floor, so I dont get cold feet. We chose the best lagging money could buy from B and Q.

I needed 5 packs of the stuff to do my lounge, it cost ￡90 to do. As im a geek I thought I would work out the payback on the lagging. Originally the heat loss in the lounge was as follows:

1992 Watts, which equates to a run cost of ￡174 a year (for that room) using my mighty RED heat pump.

All the screen grabs are from my heat load tool my guys use to size up heat pumps for our clients. Now the super silver lagging is installed the heat loss has fallen to ...........

So its fallen from 1992 to 1791 Watts, whoop whoop. The run cost has plummeted to .....

￡156 a year , that's a saving of (￡174 -￡156) = ￡18 a year. So in 5 years it will pay for itself.

so there you have it using an MCS heat load calculator you can work out the payback of your floor insulation, clever huh?