Banks can sometimes take a much more conservative approach with new developments, especially when there are very few comparable sales for larger units. Even if several properties have sold at a similar price, the valuer may not have considered all of them or may have relied on older evidence.

If CommBank’s valuation comes back closer to your purchase price, it is worth asking NAB whether they’ll review the application or accept a reassessment, although there’s no guarantee they’ll change their position. It may also be worth asking for a copy or summary of the valuation so you can understand exactly where the difference came from.

The valuation process can vary quite a bit between lenders, which is why independent property advice can be useful.

Hopefully the CommBank valuation gives you a stronger position. If it does, don’t be afraid to push your NAB lender for a proper explanation rather than accepting a vague response.