Advice needed on getting a conservatory

[ASB]

Yes - our conservatory is about 3 x 3 metres and no planning permission was required.

I assume you therefore asked you planning authority. If you didn't you are likely OK provided:-

your property is not listed
you are not in a conservation area
floorspace is < 30 m2 (obviously is)
no drainage
it's ground level
door to rest of property
roof is transparent

you still have enough PDR left allowing for any previous extension and/or total/partial withdrawl of PDR.

A conservatory does not generally need building regs.