We've got a 2-pipe steam radiator system in our 1920's home. It's worked ok for the current size of our home, but we're planning an addition and we're not sure that adding on the system would be wise. Currently, the rooms at the far end of the ststem take longer to heat and that's been a bit of a problem. We don't want to tax the system any further, asking it to heat additional rooms. Should we add a second heat system for the new rooms, and if so what kind? Or would this be a good time to upgrade the whole house to something more modern and reliable?