Some basics:
IF your husband is a true NRA (not a US citizen, no green card or expired green card, etc.) then filing jointly means you both must file an election for him to file jointly with you with the IRS. Once you do this, he will be required to file a US tax return thereafter, unless you void the election (a once in a lifetime act). Under the election, you can file jointly, or, in any given year, file separately. If, while the election is in force, you chose to file separately, your husband IS REQUIRED to file a separate US return for that given year to the IRS as well.
In addition to a pension, does your husband have a stocks and shares ISA? Does he have funds with a bank/building society in an account that utilises managed mutual funds? Will he win the lottery? (
![Grin ;D](https://www.talk.uk-yankee.com/Smileys/classic/grin.gif)
) And on, and on. Carefully weigh the short term advantages of filing jointly against longer term realities. Will he ever form a partnership in his business? Is he self employed? Will he ever have an inheritance from UK sources?
Also, you mentioned putting your name on the title to a residence. There's no problem with this, but check with a UK advisor as to the consequences (re: inheritance tax issues) of a non-UK person, either with 'joint tenant' or 'tenant in common' should the worst occur.