I loved old houses but in our 18th century thatched cottage the dds kept on getting really nasty respiratory infections due to moulds and spores. Had to move and to stay the area we had to buy modern, and bought a 1960's chalet bungalow that has been extended. It's spacious, a one-off and with a lot of character, lots of light and big rooms. The plot is large and mature, it's practical to keep and when I do yoga I can actually stretch my arms up straight above my head w-out my hands hitting the ceiling! So my vote now goes for modern.
But I would not buy new build.