Having a conservatory as an extension - open plan?

SarahLou

I've searched for this but haven't found any recent threads so apologies if this is always cropping up - the posts my search found were all quite old. (Although most said the same thing - i.e. don't do it!) :rotfl:

However, in case things have changed, I thought I'd ask myself.

We've had a few people out to give us quotes and most were of the cheaper region (£4750 to £5900 ish in price range for a 3x3m conservatory, french doors between the kitchen and the conservatory and then a pair to get out of the conservatory too, dwarf wall and a few plug sockets).

Then we had another company round who were the first and only ones to offer the open-plan conservatory. Now I have two experiences of conservatories - my mum & dads is a conventional conservatory with french doors between the house and the conservatory. Its freezing in winter. But then my sister has one that is open plan (with well insulated glass - don't know the spec - waiting for her to get back to me with that one - but even then, she had hers built about 6 years ago now so things will have improved by now anyway - but to be fair, hers is always warm, even in the middle of winter).

However, I don't know what she pays for her gas bill :rotfl:.... which is why I'm asking on here.

The company that did suggest is offered it to be done with Pilkinton K glass, argon filled units and either a choice of 35mm or even one that was 40mm for the conservatory roof (which I'm guessing the 40mm one would be the best for insulation).

He said that with these glass options there would be very little heat loss and it should be considered the same as a brick built extension.

Is that right? (I asked about whether it would be adviseable to have a radiator installed and he said he didn't think it would be needed).

What are peoples experiences with 3x3m sized conservatories as open-plan extensions (i.e. with no doors between the house and the conservatory itself) - does anyone else have Pilkinton K glass that is filled with argon? And a good - 35mm or 40mm - sized roof?

I'd like to hear from others who have had something built to that specification? Is it cold in winter and has your gas bill gone up by a crazy amount?

Swipe

If you have open plan you'll need planning permission. There's now way I'd have an open plan. You'd be burning money away in heat loss in winter and in summer it may make your home extremely hot, even with special glass. Get some french doors, that way you can have them open or shut to suit the weather.

MX5huggy

SarahLou wrote: »

He said that with these glass options there would be very little heat loss and it should be considered the same as a brick built extension.

This is utter rubbish from pilks themselves "And no matter how low window U values become, they will never approach those of the walls."

http://www.pilkington.com/europe/uk+and+ireland/english/building+products/pilkington4architects/buildregs/window+energy+ratings.htm

The U Value for the glass may get down around 1.7 to 1.2 modern walls are around 0.25 to 0.17, insulated ceilings (300mm wool) are lower still.

27col

A neighbour of mine has a conservatory which is a bit more than 3m x3m, and they have very expensive folding doors that open up the entire wall between the house and the conservatory. They do not close these doors much, even in the winter. But they do have very high heating bills they tell me.
If you have the doors then you don't have to use them. But if you don't have the doors, then you cannot use them, even if you want to. It's a no-brainer, unless you have more money than sense.

moderngirl

40mm Glass units in a roof? this sounds highly unlikely.

I work for a conservatory roof company, and input the orders. The thickest unit to go in a roof is 24mm, the largest polycabonate to go in a roof at the moment is 35mm.

35mm poly can have a u value of 1.2, where some of the high performance glass can have a u value of 1.

Uvalue is used to measure the internal heat loss during colder periods. The lower the number the grater the insulation.

Hope this helps.

SarahLou

Thanks everyone - and sorry for the misunderstanding, when I said 40mm glass for the roof, I meant polycarbonate. Initially he quoted us for 35mm stuff but he did say they do some 40mm stuff that has a slightly tinted tone to it (he didn't have a sample of that with him but he drew a diagrame to show the difference between 35mm and 40mm stuff).

Thanks for all the advice, I think you're all probably spot-on. I was hoping for different answers but I thought you'd all say what you've said.

premkit

if you can strech to underfloor heating electric or pipe in the screed. insulate the floor if you do go for it.
like above, it is a glass house and heating a room with next to no insulation all around is expensive, if you want to use it all year then heating it properly is a must.

ixwood

Of course, you could just build an extension. Or a garden room, sun room (or orangry if you're really posh). i.e. an extension with lots of windows. Or even use the funky sliding doors the full width, so you can open it right up in summer.

waynehayes

You most likely wouldn't need planning permission, but definitely Building Control notification. They would insist on insulation in floors etc.
I would definitely try to stretch to a 'proper' extension if you can afford it, you would be glad you did.

Owain_Moneysaver

If you have open plan then the conservatory becomes subject to Building Regulations (not planning permission) and would have to be insulated to current building standards or you would have to add a lot of compensatory insulation to the rest of the house. You would also have to comply with all the other Building Regulations too such as foundations and means of escape in fire.

Swipe

All conservatories must be separated from the house by an external quality door, patio door or French doors. (Building regulations)