1980's bungalow: renovate to reduce energy usage?

[ramble]

I'm am buying a 1980's bungalow with a south west/north east orientation. Living rooms to sw bedrooms to ne.

It has single glazing but according to owner has insulation in cavity walls and attic (will check).

Windows are very large. The central heating is gun metal oil fired.

We lived in a similar house before and the heat was v. inefficient.

I am looking for suggestions for efficient heating/insulation.

I would like to super-insulate (external wrap perhaps) and construct an extension to face south & west at centre rear of house to collect heat, solid block wall to north. Will replace windows, possibly reduce size to n/e. Am looking at solar panels but they seem uneconomic.

I basically want to reduce the heating bill as much as possible, in the most efficient way.

Has anyone successfully renovated this type of property to reduce energy use? Any ideas or points to think about?

 

[ramble]

Re: 1980's bungalow

There is quite a large overhang, at least 18 inches, Would have to bring gas from the main road about 400 yrds so could be expensive and would disrupt at least 20 other people. Was hoping to reduce heat requirement to a minimum, so could possibly get away with efficient oil with possibility to use veg oil in future

 

[z102]

There is plenty of advice on the issue at the SEI home page. Check [broken link removed]
Solar panels are already economical when using them for warm domestic water. If going for UFH (low flow temperatures!) then using solar power to provide part of the heating is also economical. But you need a well insulated home incl. the floor (10, better 20cm of insulation under it) and space for a big storage tank.
Try to get an energy adviser's opinion and make sure you get a heat demand calculation on which you can base a decision. Signed by the person doing the calculation in case some wrong calculation work leads to financial losses.