Home improvement loan: where to get?

Unless we're talking about absolutely necessary (ie: right away) home improvements that you can't wait for, like replacing rotting walls or something like that, I would strongly suggest just waiting until you have the funds to pay for it in cash. You said that you would expect to be able to pay the loan back in 12 months. Just save up your money in that time and do the work then. This way you don't need to worry about loans, or second mortgages or refinancing.

We bought a new house about two years ago, and since then have put about $20k into it. But that was all using cash. Trust me, it makes it much easier.

Again, if we're talking about making the home livable, that is a different story. But if you simply want nicer cabinets, you can wait a year.