The implications for removing conservation area consent and replacing it with a planning permission requirement for demolition within a conservation area was considered as part of the Heritage Protection Bill, which went through a White Paper consultation and a pre-legislative scrutiny.
During those processes there was no adverse comment of note except a concern that it should be an offence to fail to apply for planning permission to demolish - so as to retain a deterrent effect. A failure to apply for planning permission is not currently an offence, whereas a failure to apply for CAC is. This was to be addressed in the Bill by a specific offence being created. This must be replicated for protection levels to remain.
There was also mention at the time that it would effectively remove the current ecclesiastical exemption for CAC and that it would introduce charging. The latter need not be a forgone conclusion, but may not be a significant issue in any event as the planning application is likely to encompass the new-build to replace the demolished building.
As a matter of law at present one is obliged to consider the desirability of preserving or enhancing the character and appearance of the conservation area under CAC and this will be maintained if the matter were decided instead by planning permission.
As things stand now the key national policies on deciding a CAC are set out in PPS5 - to be replicated in effect in the NPPF. The policies also apply to planning permission decisions, where relevant, and to the formation of development plans. So the national policy on demolition within a CA will not change, and neither will the statutory considerations.
The only thing that could be said to change is the emphasis placed on the development plan. One way to put it would be to say we would be changing the formula from one where the decision is to be decided in accordance with law and national policy, taking into account the development plan, to one where the decision is to be decided in accordance with the law and the development plan, taking into account the national policy. Giving the hierarchy of the national policy and the need for development plans to be in accordance with it, there is in any event a circularity here that means those two are a distinction in approach without a real difference.
The net effect of the change is that what is currently taken into account will remain relevant and that the sense of weight to be given to unlisted buildings in conservation areas will remain dependent on the law and the national policies, as it is now. The real change will be noticed in the process rather than the principles of the decision-marking.