Activities outside scope of consent
If an activity is being undertaken that is beyond the scope of the relevant resource consent, care should be taken when assessing whether the difference constitutes a breach of the RMA. If so, this could make enforcement action appropriate.
The following factors are likely to be relevant:
whether a separate resource consent is required or not. If the element of difference is a permitted activity, then enforcement action is inappropriate
whether the written approval of any affected parties was obtained when the resource consent was first sought. If so, then a change is more likely to be a breach of the resource consent
why the original activity required consent
the status of the activity which required resource consent in terms of whether it is controlled, discretionary or non-complying
the adverse effects of the difference on any person, taking a conservative approach
any conditions which assist in the interpretation of the resource consent. For example, a condition the "the resource consent be undertaken generally in accordance with the plans".
This issue needs to be approached on a case by case basis.
Voiding of consent by non-compliance
The Environment Court has stated that non-compliance with a resource consent condition may give rise to enforcement action, but this does not necessarily impair the validity of the consent itself (refer to Graham v Dunedin City Council  C81/2001).
The core question in relation to this issue is: "Does the non-compliance change the activity consented to?" This was considered by the Court in Twisted World v Christchurch CC  C9/2001 where the answer to that question was ‘no’. The Court acknowledged there was no resulting adverse effect and there was no clear purpose for the condition involved at all. The change in that case proved immaterial; if there had not been a specific condition, no issue would have arisen.