I guess nobody is pleased to see his monthly bill for heating (especially here in Canada). Our homes, especially the older ones, are like Emental cheese, when talking about energy efficiency.
There are some precautions you can do on yourself (check our green living section on Toronto mls listings site), or you can order a complete refurbishment. But the problem is in aiming. Is the roof main gateway out for heat, or is it better to aim the effort on walls? Or maybe windows? and what about the fireplace?
Certified energy auditors are the ones to help you with this problem. You can order this service for about $350 for the first visit and $150 for the second one (with possible $150 government refund!) in more places (for example Windfall Ecology Centre, the pioneers on this field). During this hardly 3 hour visit, auditor will check every single part of your home for energy leaking. consequently, he will prepare a project for you to get rid of them!
Considering your energy bills, this is a very important first step! And it's not only about bills - low energy consuming house has bigger price on the real estate market. And of course - it helps our planet too!