EPC Certificate value 600

My house is built around 1947 and wasn't very well insulated. An EPC of around 6 to 700 I think.
I've since had the loft squirted full of insulating foam.
Even with this done I'm spending minimum of 2000€ on heating oil per year :(
I find this incredibly expensive coming from a modern rented apartment where the yearly gas bill was around 700€
But yeah, wanted to buy my own place and could only afford older properties so I have to take it how it is...

If possible try to see the heating bills of the owners .
Also is it a freestanding house , or one in a row of houses ?

We live in a fairly large detached house, which was probably built early 1990s. It's not brilliantly insulated, but okay. It's heated by mazout, and we are paying close to €5,000 a year, which is cripplingly high. With the wonderful gift of hindsight, I would avoid a house with mazout.

I think Dune must be doing something wrong. We also live in a fairly large detached house built in the early 1990s. It is insulated to the standards of the time (which fell well short of current standards) and, even with this exceptional winter, we are unlikely to have spent much more than € 3,000 on mazout for heating - and we live 450 metres up near the top of a ridge in the Ardenne where winter really does mean winter!

Dune, the difference between mazout and an alternative energy source is dwindling. Had you had gas your bill would probably be in the 4000's anyway so mazout isn't the problem per se.
Think your house needs further insulation and look at your heating habits to try and save some costs