Conservation Area Consent
As mentioned already, new rules on Permitted Development Rights only came into force in October 2008 and despite the claim that this was to simplify the process, there is concern that the legislation was rushed through and not thought through sufficiently. At the moment the rules appear more complex than before and it may be worth asking the local planning office for clarification on whether the conservatory falls within Permitted Development and therefore does not need planning permission. Some planning offices charge for this service.
In the old days, a letter from the planning officer would be sufficient to protect you from future legal actions, but a recent legal case ruled that a letter from the planning office no longer constitutes proof that a build fell within Permitted Development. This might not be an issue now but if you plan to sell your home at some future date, someone may ask for proof that your conservatory is legal.
The only sure way to get around this issue is to apply for a Certificate of Lawfulness (CoL) from your planning authority. This will cost about £75 and may well need planning drawings to be submitted with the application. However, as there is no regulation covering the time to process a CoL, it is sometimes quicker to submit a full planning application, currently costing £150 and which has to be processed within eight weeks.