Do I need Planning Permission to demolish my conservatory?

I have applied for permitted development approval to build a brick sun lounge, in the place of an existing conservatory.

The new sun lounge meets all of the criteria set out in the act as a Class A permitted development, however the Local Authority are insisting that planning permission is sought.

Their basis for this is an interpretation that I am replacing / rebuilding an existing building and the application then falls outside of the permitted developmet regulations.

Can anyone advise me if this is correct?

Further Details:

We are in England. Do we need to go to the planning inspectorate for a determination?

The conservatory is still seperated from the main property by means of the original patio doors. It would have been exempt from planning permission because it is only 3m x 4m. (Approx 36 cubic metres) and therefore a permitted development.

The new sun lounge will be open plan to the existing house by removing the patio doors as a rquirement of Building Regulations to achieve background ventilation rates.

It depends on where your municipality lies; everyone is different. I would bet that you'll have to go through the planning commission with drawings. Good luck.

If your existing conservatory was not separated from your house by retaining the exterior doors and windows in place then it could of had planning permission and would be classed as part of the main house.
This would then be the reason for their interpretation that you are rebuilding part of the existing building.
Also if your proposed new sun lounge is not entirely separate from the main house in the same way then it becomes habitable space and requires buildng control approval.

Edit;

It is because of your intention to remove the patio doors that you require approval as the sunroom effectively becomes an extension to the habitable space and is therfore subject to higher standards in many areas.

Generally speaking conservatories/sunrooms on residential property are exempted under Building Regulations. Below are some of the Exemption Criteria - under the Building Regulations 1991 (as amended). These criteria must be met for a conservatory extension to be classified as exempt:


a) The extension has a completely transparent or translucent roof.

b) The extension walls are substantially glazed. Must have at least half the area of the walls formed of windows. Must have at least three quarters of the area of the roof formed of glazing, polycarbonate sheets or similar translucent material.

c) The extension has a floor area not exceeding 30m squared.

d) The extension is sited at ground level.

e) The extension is permanently separated from the remainder of the property by means of a door.

f) Any radiator within the conservatory is controllable. (If fixed heating installations are proposed, they should have their own separate temperature and on/off controls).

g) The glazing satisfies the requirements of part N, Schedule 1 (toughened/safety glass).

h) The extension does not contain any drainage facilities. (i.e. sink, WC, or washing machine)

Edit,

The thing is the purpose of the building regulations is to ensure that at least the minimum standards of design and stability are met in the course of construction work. They will almost always be required when structural alteration takes place. It's the detail in your proposal that matters not how you define it.
If you were not opening up to the main house ("the existing building") it may then satisfy the exemption criteria.

You don't need to remove the patio doors to comply with Part F.

The consevatory must be thermally separated from the dwelling by walls, windows and doors with U-value and draught-stripping provisions as least as good as provided elsewhere in the dwelling.

Ventilation is provided by opening the patio door not removing it.

See b. below, note; 'which must be closable'


1.14 A habitable room not containing openable
windows may be ventilated through a conservatory
(see Diagram 3) if:
a. there is from the conservatory to outside,
provisions for both:
i. purge ventilation, one or more ventilation
openings, with a total area given in Diagram 3
based on at least the combined floor area of
the habitable room and conservatory; and
ii. background ventilator, a ventilation opening
(or openings) of at least 8,000 mm2 equivalent
area; and
b. there are openings (which must be closable) between
the habitable room and the conservatory for:
i. purge ventilation equivalent to 1.14a(i) above; and
ii. background ventilator(s) equivalent to 1.14a(ii)
above which should be typically located at least
1.7 m above floor level and need not be within
the door frame.


Rightly or wrongly I have never heard of anyone applying to demolish a conservatory/temporary structure to comply with Part 31.
I would think (maybe incorrectly!) that it applies to permanent buildings or parts of.

I can understand your confusion. I had a case 3 years ago with a 'separated' garden room with a lot of glazing and a solid roof. I wanted to put a kitchen in this space and open it up to the house. I was told by the planning people that if the roof was left in place I could rebuild the walls and remove the french doors to the house - without getting planning consent. However, you are going to require Building Regulations consent, and you could use the same information to make a planning application.

you will need planning and building regs for new brick built sun room if it has a solid roof (tiled ) but if it has a glass roof then you may not require both but a quick phone call to local building control will sort it ...but your idea of open plan to comply with regs sounds wrong ..if it has a glass roof it is classified as tempory structure ..and you must keep existing patio doors as to remove them is against building regs

You need to look at Town and Country Planning (General Permitted Development) Order 1995 to find out what is permitted development. There are restrictions on whether the house has already been extended. You are rebuilding a part of the house which already has (deemed) consent - hard to see why this would count as development.

The proposal will almost certainly require Building Regulations approval, unless you are prepared to keep it separated from the rest of the house. If defining it as a conservatory to avoid the need for regs - you need to be aware of the limitations on area of glazing/solid construction.

You should decide on the type of extension you want and if it needs approval - go for it. Significantly compromising the design for the sake of saving a few quid, when a well-designed extension will add so much value to your home seems a poor deal. If you want to save money - open a bank account.

I presume that due to the removal of the patio doors the new project would be deemed as an extension. Therefore requiring planning permission.