can too much insulation cancel out the best savings

[elliss]

Hi,
I'm quite interested in insulating my house - needs loft insulation badly and one side of the house is very exposed and needs either external or probably internal lining like sempatap - or the like. then i can lag the pipe and add draft excluders all fairly cheap....

however... i look on some websites and they say 'A will save you £100', 'B will save you £200', 'C will save you £50' etc etc.

Now, I am not taking much notice of the actual numbers but I query the rationale. If you put in every possible insulation technique then will the various saving (CO2 and £) be diluted by each others effectiveness.

If you add up all the estimated cost savings I could reduce my heating bill to ZERO.... which wont be the case

i hope this makes sense