Electric underfloor heating in conservatory? Worth it?

[wendybird77]

I've had a quote back for putting underfloor heating in the conservatory in our new house (currently there is none). The builder's quote has come back with electric underfloor heating and it is going to cost £1500 to dig up the current floor, put it in and lay new floor. I didn't specify, but I meant hot water underfloor heating when I was speaking about it. Now thinking that is going to cost even more to pipe in and wondering if underfloor heating is even worth it as I've heard the electric is expensive to run. I will ask my builder about a hot water system. Now wondering should I just have radiators put in instead? Hate to take up wall space, but don't want to spend a lot of dosh to put in an inefficient heating system in what is already an inefficient room to heat (with leccy prices ever increasing)! Someone help me!

How much do you use it in winter? Is it an integral part of the living space or an 'extra' room iyswim?

I wouldn't put electric underfloor heating in a conservatory, as the running costs would be astronomical. But I wouldn't put radiators or hot water heating in there either - they lose so much heat that whatever method you choose is going to be pretty pricey. I'd put the money towards saving up to knock down the conservatory and replace with a proper room. But I am not a big conservatory fan.

My parents have a conservatory that they only use very occasionally when the weather is cold and there's no sun (usually when they have more people there for dinner than they can fit in the dining room). On those occasions they heat it up with a fan heater - inefficient but much cheaper than installing anything if it is only a once-in-a-blue-moon thing. I can see it is a trickier decision if you actually need to use the space all the time though.

That's the thing, we need to use it all the time as it will be the playroom and is essentially an extension of the lounge with three sets of double doors opening out to it (house has a strange layout). We can close it off on cold nights, but I would expect it to be open to the rest of the house during the day with children running around. It is south facing if that makes a difference.

We are looking into underfloor heating as we are having a kitchen extension next year but we did have a conservatory in our last house which we used as a playroom.

Ours wasn't south facing but it was dwarf walled, and about 10 ft x 10 ft. It had a small double radiator and we did use an oil filled radiator in the winter time to top up the heat.

We had foils put into the polycarb roof to help with heat loss and solar heat. It had a laminate floor and we put down these interlocking foam mats from ELC to help reduce the noise and keep it a bit warmer. We used it year round.

Heating wise, why do they need to dig up the floor? The whole point of electric underfloor heating is that you can retro fit it. With hot water underfloor heating there is the problem that it raises the floor level although this stuff has just come out which dramatically reduces the raising issue.

Anyhoo, have a watch of on youtube where it shows you them laying underfloor electric heating in a conservatory.

*tis? meant this!

From what I overheard the digging up of existing screed is to fit insulation panels underneath the mats so that the heat rises rather than nicely heats the underlying concrete. I will investigate foil panels for the roof. I know nothing about conservatorys having never had one. It has short walls around the edge (maybe 1.5 foot) and one tall wall so that it doesn't overlook the neighbours. Thanks for the link (and advice!) am off to look at the thin wet system!

The only reason for floor removal would be if the current floor of the conservatory is flush with the lounge.

Ours was inherited, and tacked onto the dining room so it still had the original sliding patio doors. This meant the frame of the doors provided a lovely trip hazard as the level of the conservatory floor was level with the dining room floor and the threshold bar was raised.

Had it had been a forever house I would have bricked up one side to lose some of the windows, and put insulation and a proper roof on.

Usually with underfloor heating, they lay mats, then the heating then the flooring (sometimes they lay screed to embed the electric heating in) so I am still wondering at why your builder would want to dig the floor up.

Have you had 3 builders come and quote you for this rather than just one?

Forget about installation. Have you asked how much it will cost to run? It might be cheaper to heat yourself by burning £5 notes!

I should explain.... One of a few reasons that we discounted a house we looked at recently was that they had installed a conservatory with u/f heating as part of the kitchen (pre 2004 part L building regs tighten up and difficult to sort out heating without new kitchen etc so £££) and i nearly fainted when she told me what their utility bills were! Ok the house was bigger than ours - but their bills were more than 3x bigger. That u/f heating was a big part of that cost so beware!

If you can afford it this is a no brainier for me. I have underfloor heating (electric) in my bathrooms and kitchen/dinning area. I also have rads in these rooms. It's great even if you just have it set to a low setting as it takes the chill out of the floor. We don't have ininour utility room and it makes such a difference.

Have you checked whether it's even possible to hook up water/pipe underfloor heating to your existing boiler? I'm pretty sure you need a specific type of boiler for those systems.

Sorry, I've been at the zoo all day with the kids. To answer questions: yes, the floor is currently level with the lounge floor - so floor does need digging up to put anything but new tiles down. I e-mailed builder last night and he said that a wet system is the better job, but he needs to get surveyor in to see how much further down he needs to go (not sure why, but he is a very good builder with good reputation, so I do trust him). This may only increase cost marginally or by a lot depending on the answer. The conservatory is a nice one and was done properly (not a DIY job). I know its going to cost a lot to heat, which is why I want to get it done properly (i.e. most efficiently) the first time! We are going to be in this house for the foreseeable future and we do need the space, though I appreciate I may need to do more to make the room more habitable (tiled roof or something). It is affordable, as in we have the money, but it is costing more than I planned and I would prefer to spend the money elsewhere as we need a new kitchen, new bathrooms and I'd like a first floor extension as well . There is only a small pot of money now and the rest will have to be saved. On the other hand, I need the room to be usable and will already be spending money on messy building work (new doors through 24 inches of stone!) and want it done before we have to move in. So I guess the question is do I suck it up and have a wet system put in now, or is electric good enough, or should I just opt for radiators? Or is the quote so outrageous that I should look elsewhere?

a conservatory loses a vast amount of heat. Consider that a house to modern standards has a roof with 250mm of insulation in it, and walls with two layers of brick plus 60mm of insulation.

A conservatory has a couple of layers of glass or plastic.

This is why the energy and fuel regulations forbid you to put central heating into a conservatory, and require it to be shut off from ther house by an exterior-quality door; it is considered to be an outbuilding, like a rather expensive shed.

If you do decide to try to heat it to a comfortable level in cold weather, it will be very expensive. Energy from electricity costs between two and three times as much as energy from gas, but a wet system will (usually) cost more to install than an electric system. It is always more economical to install the heating during build, especially if it is embedded in the floor slab (which ought to be insulated to avoid cooking the worms).

A standard DPC radiator(s) connected to your existing system will be fine, the trick is keeping the heat in but this can be done by fitting special blinds on the ceiling and wall panels that insulate the room and reflect the heat back in. Insulation is the key factor not the heating itself.

Thank you everyone. Having obsessed over this my plan is to either put rads or a wet system in that can be controlled separately from the rest of the system (depending on surveyor's assessment) and look at ways to increase insulation - like putting a roof on and ensuring that the walls that are there are insulated. It does need to be usable year-round as it is a significant portion of our living space, so I think I need to suck it up and do the best I can with it. We can always close it off at night, etc to save costs. Thanks!

Hi wendybird77. We fitted electric underfloor heating in our lounge/dining room.

The room benefits from warmth under foot and aesthetically not having radiators. However, I would never fit it again.

Although it was relatively cheap to install, (my husband did it himself, bought from a company geared up to DIY'ers) the running costs are almost prohibitively expensive. We were mislead by the company as to the actual running costs, (still kicking myself I didn't research it better!) and as a result I try not to have it on too much, which defeats the purpose really!

We also installed an underlay underneath the electric matts to reflect the heat upwards and try to stop heat loss into the concrete below. And we carpeted it, which we were told was fine to do, (carefully bought a compatible carpet for maximum heat benefit) although with hindsight I think a hard floor conducts the heat better, so this was not a good idea.

Re: The floor being dug up - our hall originally ran straight into our lounge/dining room. Both rooms were level & laminated - we removed the laminate from the lounge, put down underlay, electric mats and then carpet and the two rooms are still at the same level as each other - the carpet is marginally higher, but it's imperceptible.

So for me it is about the cost really. Our electric bill is much bigger. On some level I feel the lounge must suck some of the heat out of the adjoining rooms.

If I did it again I would only consider a gas alternative, whether that is underfloor or radiators.

Sorry wendybird77 - I've been writing my reply between doing other things this morning and didn't see your last post before sending this!
Good luck with it!

Thanks Cookie - that really cements it for me, I'll defo do gas over electric whether I do underfloor or rads!