Usually a separation means that someone needs to find a new place to live.  The New York Times has a useful tool for looking at the long-term costs of renting versus buying.

You may find this tool useful if you are looking for new accommodation for yourself, but it can also be useful for negotiation purposes.  Figuring out how to structure a settlement to meet both former spouse’s needs can be the hardest part of resolving a separation or divorce.  Even if legal entitlements are clear, it is foolhardy to expect someone to accept a settlement that leaves them unable to meet their basic expenses.  And if someone is fixated on the need to purchase a new home, this tool might help to adjust that expectation.