Thanks for that, kkma.Got this done around 2005, went the combi boiler route, installed 7 or 8 rads and think the whole thing was about €7000. Sorry to be hazy but we were also getting bathroom done. House had floorboards so pipework was easy to put under. 3bed terrace house. Wasn't a huge job. House was piped for gas already.
had this done 2 years ago also (oil,not gas as no gas mains to the neighbourhood)...3bed semi - 7 rads - cost 5,000e.A fair bit of disruption but worth it. Had to replaster walls where pipes were chased and repair a few floor boards. Bath had to be removed and damaged tiles in the process but not an issue for me as bathroom was next on the list to be updated.