If you don’t want to buy a already made conservatory you can hire an engineer and he can custom build it to your requirements (there is an information and price guide here). Your home will benefit from taste and beauty with a superb conservatory.
Investing in double glazing can be a really positive move, so why not go to this cost guide today and find out how much it would cost to get your home fixed up.
This will provide a layer of insulation that is more efficient than actual bricks as new technology is pretty advanced. Plus, double glazing repairs are cheaper than they used to be too.
Having said all this you will of course still need to convince your parents that getting all this stuff (at the best prices)is a good idea.