I would like to radically alter my bungalow, taking it up a storey and dividing it into two, so DS and I can live in one half and the other can be sold off as a separate home (and hopefully pay off the mortgage). I have a lump sum to pay for the work. The planners are supportive. I have a good builder lined up.
The roof will have to come off and the massive windows removed in order to take it up a storey/remodel it anyway - which I understand I can do without needing to notify my mortgage lender. The builder has said that if we could just knock down the few remaining walls and rebuild on the existing foundations, we'll end up with a much, much warmer house (it's freezing in winter), a more predictable build, and more freedom with planning the internal layout.
This is really appealing. What are my options? Can I raze it and start again? I'm guessing not, as the house is the security for the mortgage. It isn't an option for me to apply for a different kind of mortgage (such as a self-build mortgage), because (a) I don't earn enough for anyone to lend me much, and (b) my current payments are so fantastically affordable - lower than they'd be with a new mortgage. So I need to work within the confines of my existing mortgage.
What are my options? To what extent can I demolish strip the existing bungalow back to its shell without needing to change the terms of my mortgage?