Most of the replies here are unkind to say the least.
If this man had been married, the courts would have awarded a fair settlement. That would usually involve the marital home being sold and the assets divided according to need. The ex wife may have ended up with 50 % of more of the equity, but she would be expected to work and provide for her children as well as their father.
As it stands, they have come to what seems an unjust agreement, which means he is going to struggle to buy a home with his current partner until his children are 18.
Ironically, MN is full of advice that women should marry to protect their assets and home if there is a divorce, yet here, the woman is far better off than if she had been married! Simply because she has got her ex to fund her home for another 10+ years.
Yes, mothers can often stay in the marital home with young children, BUT the overall settlement takes into account the father's needs too, for his own future. That could be reduced maintenance and the instruction that his ex finds work.
OP you can't force this man to sell his home (assuming he owns half of it) but you can try to hold onto your own career and build it so that if he walks away, you can support yourself and your child. OR you can try to convince him that he needs to stand up to his ex partner and force a sale (or she takes on the mortgage and buys him out of his half.)