We’re thinking of having a conservatory added onto the back of our house, however as it’ll be sandwiched between next doors extension and our kitchen wall (kitchen jets out 2.5m beyond the rest of the house) it’ll have full height brick walls both sides and a triple glazed glassed roof with a ‘u rating’ of 1.1. Reading the building regs it says that we need to have an external quality door between the house and conservatory but as it’s only really going to have a glass roof and sliding door at the garden end would it still be classed as a conservatory and therefore need the internal doors or could it be classed as an extension?

You’ll probably appreciate the door if it dies get cold.

I had one that could just lift off the hinges so it got taken off in the Sumner and back on when I got dark and cold.

No-one is going to check but you’ll want the door in winter. You can feel anything with a lot of glass sucking the heat out of the house.

Building regs dictate you need an external graded door between the conservatory and house. And you really want one for the warmth. Gets awfully cold.

You need an exterior door WHEN THE BUILDING INSPECTOR VISITS.

If it falls off shortly afterwards and is replaced by a normal door then you will be fine.

See if you can borrow one from a double glazing company (or a skip) while the inspector calls.

We had to change out conservatory when we extended the kitchen. One pair of the original interior double doors wasn’t affected bu the other double door were converted to a single door. The inspector insisted that was replaced with an exterior door because the regulations had changed making it required.

It was ridiculous and the inspector agreed.

We built just such an extension/conservatory and kept the external door. It was a warmish room, such that the underfloor heating we installed rarely got used. It was sandwiched between the neighbours wall and the outrigger of our house where we had a utility room and shower/toilet room built.Think the heat from the boiler in the utility and radiator in bathroom did help to warm it however. I would keep the external grade door as feel it did make a difference.

As we did it in stages and converted the outrigger first we actually built an outside toilet to begin with.

Another advantage was because it was close to boundary wall we would have had to have planning permission for an extension vs nothing for a conservatory.

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16/10/09 Work starts by Moose, on Flickr[/img]

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P1033498 by Moose, on Flickr[/img]

You need an exterior door WHEN THE BUILDING INSPECTOR VISITS.

The only time we saw a building inspector was when he came to look at our back yard and told us that he couldn’t understand why anyone would want to build a conseravtory. Never saw him after that.

Is it usual for them to come back?

Do you need a robust door for security? Some of those sliding doors had a bad rep in the past.

Hmmm, I was hoping as the roof and door/window would be triple glazed heat loss wouldn’t be such a problem. Maybe we’ll have to price up a normal extension as we really wanted it to extend the current living area but to let as much light in as possible, hence the glass roof.

Half the ground floor of our house is a conservatory. No adjoining door. Heat loss is not much of a problem.

It’s bloody lovely.

We looked at almost identical thing to bruk. We worked out heat loss and gain, and ended up with a solid roof, with skylight in, and much less glazing. The glazing was cleverly done so that sat at table, r when washing up etc you could see through into garden. It did not have a door betwixt kitchen / old dining room and new “connecting” section.

We looked at almost identical thing to bruk. We worked out heat loss and gain, and ended up with a solid roof, with skylight in, and much less glazing. The glazing was cleverly done so that sat at table, r when washing up etc you could see through into garden. It did not have a door betwixt kitchen / old dining room and new “connecting” section.

100_0830 by matt_outandabout, on Flickr

Hidden behind the mini_oab is the new bit nearly finished.

Picture2 644 by matt_outandabout, on Flickr

For a ‘normal’ extension not needing doors you can have glazing equivalent to 25% of the extension floor area plus the area of any openings you are removing (eg the existing back door/window). There is a caveat for allowing extra glazing if the extension causes problems with getting sufficient light into the rest of the house. You will need to meet thermal regs but there’s a few tricks there too.

A conservatory requires simpler planning and building regs so while the doors might be a passion they might save hassle elsewhere.

Conservatories are exempt from building regs, but only if:

They are under 30 sq m
Walls are 50% glazed
Roof is 75% glazed
Any heating installed is independently controllable
Thermal separation is retained between conservatory & house (that’s the external door bit)

Failure to meet ANY 1 of the above points means it is not exempt & is subject to a building regs application.

That doesn’t however mean you need the doors, there are more complex & expensive means of achieving compliance, generally by upgrading insulation or heating in some part of the existing house, upping the performance of the thermal elements in the conservatory/extension, or both, but you need an energy calculation to demonstrate compliance, either the ‘area weighted u value’ or ‘whole dwelling’ method.

Either basically has a similar logic, trying to prove that the extension is no worse than a comparable, compliant extension, or the whole house is no worse than with a compliant extension, but it’s quite in-depth and difficult to achieve in my experience. (5 years in building control).

The reality is glass (even top spec. modern stuff) performs much worse than insulated (to current standard) walls in terms of heat loss, so there is potential for your conservatory to act as a huge heat sink & dramatically reduce the efficiency of your house. Solar gain should be taken into account if you have a calc done, as above.