Underfloor heating for extension only

[ThisIsTheAge]

We're getting a 6x6 block extension and our boiler is on its last legs. The boiler engineer suggested underfloor heating for the extension which will be the kitchen/diner plus 2 bedrooms above. Is it extortionate? Is it efficient? Would only having it in the extension and not the rest of the house be a pain/bonus?

Every single room in the house needs doing so pipework etc is no bother. Just looking for advice from people who've done it/not done it and why.

Not me personally but a friend of mine put underfloor heating in their kitchen when they extended and you really feel the difference between the heated floor and not but only in bare feet. If you walk around bare foot then do the whole house. If you use indoor shoes/slippers then I wouldn't bother

We just finished a kitchen extension this past winter, and had to put underfloor heating in there because the walls didn’t have enough space for the size radiators we needed (big windows and units and bench seating). Yes, you can certainly feel the difference when you walk into the older part of the house, but it’s warmed even the other rooms up slightly.

We've just moved from a 3 bed terrace (so heating benefit from neighbours you'd think) with normal boiler to 4 bed detached with underfloor heating downstairs only. In 7 weeks weve only put the heating on upstairs twice. The underfloor heating is on for 2 hours max a day (not right now at all as its warm) and that has been enough to warm the whole house and top it to 20 degrees. I can already see our heating bill from the terrace to this will be considerably lower overall.

I would make sure its wet u/f heating as electric is very expensive.

weve got it whole house apart from the garden room. We hardly use it upstairs but we do have an AGA on 24/7 in winter so that helps.

i worry about what happens if something goes wrong with it as that would mean digging up all the floors!

We have half and half - I'd have it everywhere if it were possible. No radiators on walls, constant temp - perfect. They run off the same boiler but have different controls so run at different times and temperatures.

It’s takes longer to heat up and cool down but you will quickly get used to a slightly different way of planning for that. In winter leaving on low all the time is the most efficient way in most properties.

Wunda is a good option to retro fit on other rooms if you want to do more of your home.

Our kitchen extension is the only bit that has underfloor heating, same flooring runs throughout into the old part.
Yes, you notice the difference on your feet but not in the air. The cats lay on the very edge of it, they know where it starts and stops.
Make sure it's wet, as someone else said, not electric. It runs separately to the rest of the radiators throughout, I don't think it makes any difference to having a couple of radiators. I'd say it could be slightly more efficient as it heats up the concrete slab which then retains the heat.

This is all really useful thank you.