Underfloor heating cost & advice

[Pulp]

Hi All,

Having a new extension built in the next 12 months which will be 61m2, including knocking into an existing room (14m2) which has a concrete floor. I'm wanting to put underfloor heating in and have a tiled floor (wife wants porcelain tiles - maybe thats another post) so far I've done a bit of reasearch and decided I probably need 4 zones. 12 for the utility which will be 16m2, one for the 14m2 existing part and then two for the remainder, one as it is front of bifold doors and the other as it'll be more shaded.

Builder is saying this will add £8k to the price, even though he's got to pour the floor anyway, so I'm thinking this is quite expensive. Found and online parts and quote estimate a while back, which I can't seem to find now which suggested should be nearer to £5k, any thoughts?

The 14m2 floor will have to come up this is concrete already but I've said I can do this myself over a weekend ready for them to start the next week. He was OK with that but non commital over any price change that would make.

Also readig a lot on line its saying it should represent a 35% running cost saving due to the lover temperate the floor heads up to vs radiators. Also the cost of having some 'designer' radiators at about £300 each means it'll cost me the best part of £2k for those plus fitting, so if I'm going to get 35% back it'll pay for itself in the long run.

Anyone had underfloor put down or fitted it to this area size and it is but right price wise or is it too much?

Thanks

 

[oldbutnotdead]

I'm always suspicious of quoted energy savings- 'lower running cost' for instance often translates to 'conventional heating cost £1 per hour, our miracle system 40p per hour.
The trick here is of course the conventional system runs for 8 hours a day to keep the place comfortable, the miracle system has to run 24 hours a day to do the same job. Now find the saving....

That being said, in a large space like yours (especially if there's lots of glass skylights) UFH may be better for comfort.

And then doing a joint diy/pro build. Hmmm. Digging the floor out is fine-where's the rubble going? If you reckon you could do it in a day then so could his labourer so you're saving £100? £150? He'll get a better price on skips/grabs than you as well.

Is your builders price supply only or supply and fit? Either way, you need to check your online quote includes everything you need and that the prices are current. Stuff has been volatile the last couple of years.

 

[DP]

Pulp, go for overlay on existing floor and full works for new area

Overlay is panels fitted to existing flooring and I think 12mm pipe laid.

Pulled this off the web, second website I looked
at.. https://www.sophierobinson.co.uk/overlay-water-underfloor-heating/

Have done both at sons place (two properties, previous and present

In the extension, surprised the builder wants to hike up the cost as the timber floor and sheeting will not be required

UF V Panel rads.
Panel rads require high temperature; heat build up starts from the ceiling with floor area being the coldest; good chance boiler will not be condensing if run at full wack

UF floor.
Max temperature is 50 or so; boiler will always be in condensing mode and condensing will be far superior than radiators could maintain whilst attain same ambient temperature; floor slab is always at a temperature that warms the feet, more comfort level. Then there is controls for the UF hearing, good controls make the system superior to radiators.

 

[Pulp]

Thanks for the replies, the floor in the old area is concrete but all over the place so will need self levelling, plus it was put down 40 years ago so I thought might as well get it up and start again so it meets current specs/regs.

 

[DP]

Thanks for the replies, the floor in the old area is concrete but all over the place so will need self levelling, plus it was put down 40 years ago so I thought might as well get it up and start again so it meets current specs/regs.

Did not do that sons place, works ok