DU advice about keeping warmth in winter affordable? [View All]

[BelgianMadCow]

I think many are in our situation :

The cost of heating oil has basically doubled over the last couple of years. Thus, the heating of our modest freestanding 50 year old home takes about 3500 liters/year, costing (0.79 euro/litre) 2800 euro say 4200 dollar/year or some 350 dollar/month. To me, that is pretty insane.

We have subsidies for solar panels, so that is a possible investment (:-/).
Our windows are single pane, so there too an improvement can be made albeit even more costly.
We keep the temp at 21 °C with a timer 6.30-9 and evenings.

Any other advice from experienced DUers on how to keep your heating bills down would be greatly appreciated!

regards
bmc