Is it okay to do a house swap with someone permanently? Any tips etc

If you find someone with a property that you desire and it has a value equivalent to yours, you can certainly pursue a "swap." You would essentially be buying their home for a set value and they would be simultaneously be purchasing your home for that same price. You would want a local attorney to prepare a comprehensive Agreement of Sale spelling out all of the terms, conditions, and contingencies, and new Deeds would be required for each property as well. There may still be tax implications, including Realty Transfer Tax, and you should discuss those costs as well with an attorney and/or accountant.

Not sure what a swap might mean legally. If you mean that you both will sign deeds over to each other to transfer the property, that is ok and legal but you both would want to do a title search to ensure no surprises are in the transfer.