I have been idly considering, for several years, a lean-to greenhouse,
along the south facing side of the house.
It's nowhere near a road or neighbours, and the house is sunken on that side,
with a 1m path, to a 1-2m wall.

This would be integrated with ventilation, and cooling systems, to aid
in house heating, to reduce bills, and keep it cool.
(as insolation will reach 30Kw or so at peak)

Neglecting this aspect, what is this with regards to building/planning
regulations?
Is it a greenhouse, a conservatory, ...

Does this change if there is a 1cm air gap between this and the house?

Ian Stirling wrote:
I have been idly considering, for several years, a lean-to greenhouse,
along the south facing side of the house.
It's nowhere near a road or neighbours, and the house is sunken on
that side, with a 1m path, to a 1-2m wall.

This would be integrated with ventilation, and cooling systems, to aid
in house heating, to reduce bills, and keep it cool.
(as insolation will reach 30Kw or so at peak)

Neglecting this aspect, what is this with regards to building/planning
regulations?
Is it a greenhouse, a conservatory, ...

Does this change if there is a 1cm air gap between this and the house?

It's a temporary structure and you don't need planning permission, although
you can expect a deluge of posts to tell you that you do, by the brigade who
apply for planning permission each time they want to mow their lawn.
Our building control aren't even interested in conservatories

Phil L wrote:
Ian Stirling wrote:
I have been idly considering, for several years, a lean-to greenhouse,
along the south facing side of the house.
It's nowhere near a road or neighbours, and the house is sunken on
that side, with a 1m path, to a 1-2m wall.
snip
It's a temporary structure and you don't need planning permission, although
you can expect a deluge of posts to tell you that you do, by the brigade who
apply for planning permission each time they want to mow their lawn.
Our building control aren't even interested in conservatories

Why is it a temporary structure?
Serious question - I would hope it to last ~20 years with no
maintainance (barring glass) and be anchored to the existing wall.
Ok, it can be removed moderately easily, but, so can some of those
german kit houses.

Ian Stirling wrote:
Phil L wrote:
Ian Stirling wrote:
I have been idly considering, for several years, a lean-to
greenhouse, along the south facing side of the house.
It's nowhere near a road or neighbours, and the house is sunken on
that side, with a 1m path, to a 1-2m wall.
snip
It's a temporary structure and you don't need planning permission,
although you can expect a deluge of posts to tell you that you do,
by the brigade who apply for planning permission each time they want
to mow their lawn.
Our building control aren't even interested in conservatories

Why is it a temporary structure?

Because if you sell the house, temproary structures don't come into it...if
it was a permanent structure like an extension, then the buyer (or more
accurately his solicitior) will want to see plans, dates passed, details of
BCO visits etc, with temporary structures, you can dismantle and take them
with you and they don't affect the price nor deeds or any other legalities
concerning the property.

Serious question - I would hope it to last ~20 years with no
maintainance (barring glass) and be anchored to the existing wall.
Ok, it can be removed moderately easily, but, so can some of those
german kit houses.

It may be anchored to the house but so is a side gate / fence / iron
railings etc, they are attached *to* the house but they are not part of it
IYSWIM.