How much can you alter your property without having to notify your mortgage lender/get a different kind of mortgage?

[BuddingBuilder]

I've posted about this on Property too (here), but this might be more of a finances question.

If you have money sat in the bank with which you could do extensive work to your house, on a sliding scale from popping a solar panel on the roof or changing the glazing, through extending or converting the loft, all the way to razing it to its foundations and rebuilding it ... what are you allowed to do without notifying your mortgage lender and possibly having to change the terms of your mortgage?

I want to knock it down and start again - but have a feeling that's going to be a no no.

Thanks.

to true you can do any improvments to your home but you cant knock it down and rebuild ! not without the consent of your lender if you do you take the risk that if they find out you will have to repay the morgage imediately or they will reposses whats left. they normally will only let you do this if the land is worth the morgage.