Joint Tenant vs Tenant in Common!

Sean24889

Background info, my partner and I have been together for 8 years and are currently into our second house, initially she contributed £12k to the deposit and myself £8k, we broke even with the first house so this pretty much transferred to our new property. 
I earn quite a good salary around 80k whereas my parter earns around 20k and has taken time off work and not contributed to mortgage etc. Now I understand that as we are on the mortgage and solicitor paperwork down as joint tenants we are 50-50 in ownership regardless of who contributes what to the household bills and mortgage. Our monthly bills run around 1200 per month and when she is working I contribute 800 and her 500 {solely mortgage, council tax, water, electricity and insurances}. However because I earn a lot I tend to waste a lot on the house, for example recently spent 15k landscaping the garden, 5k installing a fancy logburner, which isn't an issue until, if it did happen we decide to go separate ways then I could have added considerable equity to the house, to be split 50/50.
So with our relationship somewhat uneasy at the moment I wanted to hear your thoughts on the possibility of changing from joint tenants to tenants in common. I thought and not sure how possible this is, is it possible to set ownership of 50% each at the value we bought the property and any percentage increased based on that 50%. This way it would protect her interests, she is still 50% owner of the house and would still contribute less to the mortgage etc but it would also protect myself with all the additional spending I am doing and the value that its adding to the property. I'm not sure if I have explained that well so we bought the house for 260k we could agree that we both own 50% of the property at that price, if we split up and sell it in a years time and the property is valued at 300k would it allow for me to minus the additional money I have spent on the garden for example and remove that from the sale price and we would then be back to a 50 50 split on what the property would be worth without the additional outlay from myself. 
It sounds very shallow but currently I could spend 50k on the house, pay the majority of the bills and if we part ways it's a 50 50 split, i obviously want a nice property and don't mind paying I just don't want to basically throw it in the fire should we split. 
So is this possible? 

kimwp

I think you would have to specify what the new split in ownership is in the tenants in common contract to take account of additional money put into the house. So regardless of what you spend on the house after the contract is drawn up, the 50:50 (if that's what you agree on the contract) would apply. Unless perhaps you have a clause which says to adjust it based on what you spend - then you'd have to keep track of what you spend (which sounds a good way to accelerate a breakup). Another consideration is how you plan  to relate spend to additional value added to the house - they are not necessarily related - are you going to ask the buyers how much less they would offer if there was no wood burner for example?
On another note, personally I think an 800:500 split on household outgoings with an income split of 80k:20k a bit at odds with the idea of a partnership. Another poster put it very nicely on another thread - "I love my partner, why would I accept a lower quality of life for them than I for myself"  - just a thought.