That is a commercial question for you to decide.

A $250k limit is the minimum required by the NZIA AAS terms of engagement, but in residential projects that limit may be unenforceable as a result of the consumer protection legislation, and many non-residential projects clients are seeking a higher level of cover. The prospect of potentially facing uninsured losses (ie a claim above your level of cover) may be unacceptable.

In the 21/22 year, approximately 25% of members carried only $250k cover, and these were typically 1 to 3 person firms.  Less than 5% of members carried either $350k-$400k or $600k-$750k.  The remaining 70% of firms carried either $500k, $1m, and higher cover.  Future premiums will vary according to rates yet to be negotiated with insurers, and also according to your practice income and type of work, but, subject to those changes, increasing a $250k cover to $500k would represent a premium increase of about 10%  and around 20% for $1M

When starting in practice, it is common to take a $250k limit whilst in 'start up' mode. How long ago was that? It might be time to review your PI limit.

Bear in mind the following:

• For the type of work you are doing, what is the potential value of a claim?
• What is the probability of such a claim?
• If the claim is more than your cover, what might then happen?
• If the consequences are that you might be personally liable, what is in place to protect your assets or the welfare of your family?
• The value of your projects may have only a tenuous relationship with the appropriate level of cover:  the complexity and nature of those projects (and clients) may be more significant.
• Under the Consumer Guarantees Act you cannot put a cap on your liability in respect of services supplied for personal or household use.  (The curious can explore NZIA Practice Note 1.206). This applies to most, if not all housing projects done for private sector clients or which are on-sold to consumers, and there is the potential for courts to expand the net wider.