Conservatory Definition in building regulations

[LemonSqueezy]

Hi

First time poster but have read the forum alot for helpful advice on a number of issues. First time ive had to ask for advice. Ive tried to do my homework first rather than expect an answer on a plate, but ive come up a little short.

I am planning a conservatory / Orangery to the rear of my property. Plans are yet to be drawn up. My understanding is that i do not need to notify the local authority building control (aside from compliance on new elecs installation and glazing thermal values / toughened glass requirements). I say this because:

1. It will be pretty much exactly 30m2 in size, no larger.
2. It will have an external quality double glazed (already existing) lockable door between the new room and the existing house.
3. It will not have a heating system that is connected to the existing house.
4. The roof will be 75% glazed (large roof lantern)

My only issue is with the vertical glazing (windows and doors) and how much needs to be glazed. I have searched the regs (2010) for a definitive answer on this and have not come across it.

Many installer websites state at least 50% of the wall must be glazing for the property to be a conservatory. Some state that there is no given value (% of wall surfaces to have glazed finish), others simply state that it must be a 'substantial' amount of glazing.


Why not ask the BCO, you may ask. - My local BCO who i spoke to on Friday says a conservatory must be glazed 'all round' - i know this is wrong, as it may be 'part glazed', but i didnt want to seem contrary and get his back up, so i said 'ok ill see what i can come up with'.

Class 7 (Extensions) of Schedule 2 Exemptions states:

Extensions The extension of a building by the addition at ground level of— 44 (a) a conservatory, porch, covered yard or covered way;
where the floor area of that extension does not exceed 30m2 , provided that in the case of a conservatory or porch which is wholly or partly glazed, the glazing satisfies the requirements of Part N of Schedule 1

Part L1B makes no further definitions to amount of vertical glazing.

Please can someone let me know / direct me to any specific addendum / Annexe that defines the amount of vertical glazing required?

The reason I ask is that at the moment im about 60% Wall and 40% glazed openings. For the sake of a slightly larger window i could avoid building regs notification and all that ensues. (PLEASE dont get me wrong - I am not seeking do things incorrectly or on the cheap, as I want this to be a lovely addition to the home - but the BCO's locally are notoriously fickle and difficult).

I would feel much better armed if i could find a definition of the vertical glazing requirements to define what is a conservatory, and thereby what is an exemption and what is not.

Many many thanks in advance.

Steve

 

[tony1851]

Have a read of page 2 of this:

 

[frutbunn]

I personally would treat it as exempt however, it is open to interpretation, generally most LA's will follow LABC guidance, although the LA's I've worked at, we were a little more relaxed on the amount of masonry to vertical glazing than the LABC guidance, to be honest we didn't really pay that much attention to the walling.
I do know of one authority who say its not exempt if the external ground level is even just 300mm above internal floor level on a sloping site as it is not at ground floor level!!! Even though it means at ground storey!
Your BCO does seem a bit pedantic, but he could just be following the official line of his manager, I've been in the same position myself.

 

[LemonSqueezy]

Hi Tony,

Many thanks for your quick response, I have not seen this document which is very helpful indeed.

I see the term 'Conservatory' is much better defined here. Furthermore, as external walls to the side of the conservatory shall be within 1 metre of the boundary, these are exempt from the 50% glazing (i was reluctant to have windows in these walls anyway as they offer little light).

If i may ask:

This is 'Guidance' rather than 'Regulation'. Can the BCO circumvent this and still state i need to have 50% glazing all round? I want to be able to get the plans drawn up, without going through several iterations of whether it has windows to the side or not. Would I have any grounds to challenge, if they state that it must have 50% wall formed of glazing.

Thanks again

Steve

 

[LemonSqueezy]

Thanks Frutbunn.

I was writing a response and didnt see your comment. Much appreciated. My site is not sloping so i am quite certain i meet the 'ground level' requirement.

I am now drawing up some draft plans to run by the BCO to be certain that this is acceptable. I have had a further thought, probably pedantic but i do want to get things right.

Where the LABC guidance requirement states that the roof shall be covered by no less than 75% translucent materials, I assume this is the external roof area, (not including fascias and guttering), rather than the internal ceiling area against size of opening (roof lantern).

Im hoping to install a roof lantern and have around 300mm of ceiling around the lantern inside, if you know what i mean. Based on this, i'm > 80% glazed, as such. When i factor in the external roof area (principally the addition of area above the internal + external walls and cavity) then I am at 72% roof glazed, so ill need a slightly bigger lantern, which pushes me to 250mm ceiling around lantern. Not a huge issue, but just looking to be sure.

Many thanks once again.

Steve

 

[frutbunn]

The sloping comment was just to demonstrate the peculiar interpretation adopted by some LA's. in that particular instance the BCO agreed off the record it was incorrect but had to follow the official line.

For the purposes of measuring area under B Regs the generally accepted method is to use internal dimensions.

Would I have any grounds to challenge, if they state that it must have 50% wall formed of glazing.

Interesting question. There is a mechanism within the Building Act that allows for determinations to be submitted to the Secretary of State when there is a dispute, unfortunately this for an application already submitted and relates to some part of the work rather than a matter of interpretation prior to an app being submitted. I even reread that part(s) of the Building Act for the first time in many years.

The only other way I can think of is if the work was carried out without B regs and the LA take enforcement under Sect 16 of the Building Act. You could challenge this arguing the work does not require B Regs due to it being exempt, this assumes the LA will pursue it that far. Its also risky, if the magistrates don't accept this as a defence you could end up being prosecuted and fined and having to alter/remove the work.

I'll try and do a little more research as I'm sure this isn't the first time this question has arisen.

 

[LemonSqueezy]

For the purposes of measuring area under B Regs the generally accepted method is to use internal dimensions.

Many thanks again for sharing your knowledge. It is really appreciated. If the above is generally accepted, then i shall work to that and confirm with BCO today on the phone, to see where i get. Id really like something in writing from them though....

I saw that the 50% wall should be measured as the external wall area, which is why i thought the external roof area applies. Now i re-read it, it means external walls as opposed to internal partitions being included i guess.

 

[Notch7]

You will struggle to get the roof glazing to 75% -that only leaves a small flat roof section

Ive built quite a few orangeries with smaller roof glazing area and got the LABC to agree its exempt.
What I did was email them a drawing with the words: "this is orangery is substantially glazed, it will be under 30 sq metres and thermally separate from the house, do you consider this to be an exempt structure" -and they always said yes by email. I personally used to get the client to sign that they took full responsibility whether they wanted to accept that as confirmation or not.

I can only speak for my experience in my area.
Frutbunn is I believe a building inspector so has far experience than me on this


I do know the description of a conservatory was removed from the building regs and it has left it all rather vague.

by the way, building control will accept it if you extend your central heating out into the orangery provided it has separate controls, ie TRVs......although I had an argument with one private building inspector on this who refused to sign off the job due to this, until I was able to provide him with a copy of a building control guidance note that dealt with this exact issue.


one final point: do you not want an orangery with a smaller lantern and open to the house, to make it a real extension to the house. For the sake of getting building regs, it would be worth it. I did almost no job that wasnt under regs almost every client wanted a big opening knocked through. Believe me once you have an orangery you will spend your whole time in their and wont use the lounge much any more. Most of my clients said it totally changed the way they used the house. The lounge only became used for watching TV at night.

 

[LemonSqueezy]

Many Thanks Notch.

I really dont wish to have a permanent opening between the new orangery extension and the existing house. I have external quality double doors there already and would like to keep the separation. This isnt me seeking to avoid building control notifications - the doors will stay whether the additional works are notifiable or not.

Also, yes i saw the LABC guidance on having the thermostatically controlled radiator valve in the document attached above - ill be sure to mention it to get their views.

I have had a reply from the local BCO (different one and seems much more amenable) who has stated that the requirement for a minimum glazing has been removed (not present in Approved Document L1B, 3.15). Ultimately looks like its not going to be a problem, so many thanks all.

Steve