What should parents-in-law do to get their eldest son to pay for building a house for their children and talking to their grandchildren?

My husband's hometown is in a remote mountainous area, and my in-laws have little savings, basically no income, no old-age insurance and no medical insurance. My husband is an only child with two older sisters. According to rural customs, in-laws are supported by their sons, and if they build a house, they are inherited by their sons.

My husband and I are basically married naked. My in-laws didn't give bride price jewelry, and we didn't have a house or a car. We all work hard by ourselves. We worked in a first-tier city, bought a house after marriage and are still repaying the loan. One child, considering a second child. At present, there are some savings, enough to build a house and decorate my hometown (more than 500 thousand). I am an only child, and there are two old people to support here.

The house in my hometown has been built for more than twenty years, and now my in-laws are in their early seventies. They feel that the house is leaking and does not face south. They want their son to pay for it, but they don't agree to repair it.

I think my husband and I are under great financial pressure. First-tier cities are expensive. We should raise one or two children and four old people. Besides, my in-laws basically have no income and security. We are unlikely to go back to live when we build a new house. Our registered permanent residence is not in our hometown, so we can only inherit the right to use the house. I'm going to save some money to buy a semester room, which can be used as an investment for children to study.

At first, my husband and I opposed their Gai Lou, and my in-laws were often angry and noisy. Later, my husband couldn't bear to make them unhappy and wanted to promise them. He also understands that the old people build houses mainly for face and appearance, and rural people take building new houses as their lifelong career and pride. However, it is hard for me to accept such a swollen face as a fat man. What should I do?