This will depend upon the following:
How old is it? If historic you may be okay.
Is the conservatory built at ground level and with a floor area of less than 30 square metres? Hopefully it is.
Are the walls and roof of the conservatory substantially glazed with transparent or
Is the glass safety glazing; and did it comply with the British Standards in force at the time of the installation?
Is the conservatory separated from the existing property by a wall/door or glazed screen? If not, this is an issue.
Was the entrance leading to the conservatory from the property altered? If an RSJ beam was needed then so was building regs.
Is the conservatory heated? If so how? New gas and electric installations require building regs.
Any new plumbing installed? If yes, then again building regulations apply.
Is the conservatory more than 50 cubic metres in size? If so, then you are in trouble.
Does the conservatory exceed the height of the original dwelling? Does the overall height exceed 4 meters? Again it should have building regs consent.
Is it nearer the highway than the existing home?
Is the conservatory on any wall of the property so that it fronts the public highway?
If any part of the conservatory is within 2 metres of the boundary fence, does the height of the eaves exceed 3 meters?
Does the width of the side conservatory (if any) exceed 50% of the width of the original home?
If you should have obtained planning, and / or building regs, on sale you may need to pay for indemnity insurance.