Our neighbours put up an extension similar to that substation, when I asked them, how come we did not get a letter asking if we agreed with the proposal of the extension, they said it was a conservatory and not an extension so planning etc was not needed.
I immediately wrote to the local council planning dept, they sent a guy round to check it over, and then later wrote to our neighbours and told them to take it down immediately, because it did not meet their definition of a conservatory.
"Domestic conservatories are generally exempt from Building Control if the following applies:
1. Internal Floor area of less than 30m2.
2. Not less than 75% of it’s roof should be be glazed or made from translucent material.
3. Not less than 50% of it’s external walls should be glazed.
4. There should be separation (i.e. no permanent openings) between the conservatory and the rest of the property.
5. Safety glazing – as per the requirements of Part K, Schedule 1 - to be used in all critical areas.
6. Construction is at ground floor level.
7. If there is to be heating in this area it must have separate time and thermostatic control so that it can be isolated from the rest of the heating system."
If going for solid roof, OP should definitely check with the local council on their definitions of what is or is not allowed under their ideas of conservatory or Extension, better to be safe than sorry later.
).
