I would suggest you to convince your partner or the freeholder owner. But if then also if he is not understanding the situation then you only have to pay for the maintenance. But don't worry as I know some sites like
https://westinnielsen.com/ provides you good quality services at an affordable rate. I know its not fair to pay the bill alone but if you want to make the exterior part of your house look beautiful then you have to pay for it. Don't worry once the matter solves you can ask the freeholder to pay half of the money.