Kitchens sold in New Zealand must by law carry a 5-year guarantee against failure or faults caused by poor workmanship. This only applies to cabinetry, not to appliances, which have their own guarantees.
Actually the guarantee is probably the last thing you should be concerned about. All guarantees have a clause that excludes fair wear and tear, which sets in as soon as you start opening and closing the doors. Poor workmanship is likely to become apparent quite quickly. The outfits that specialise in cheap kitchens usually have a guarantee that is equally cheap. The length of the guarantee is immaterial.
The best guarantee against poor workmanship is the care you take to choose a kitchen maker who will do the job properly in the first place and value their name and reputation in the second. Secondly ensure that the kitchen is installed properly before you pay the final invoice.
Your safeguard immediately after installation and guarantee of a good job and after-sales service is the retention. The kitchen maker will be very keen to get that last cheque. Even if it’s only 10% it will probably represent a good proportion of his profit.
The period after installation and before payment of the final amount is often called the Snagging Period. During this time unforeseen problems might occur, mistakes and omissions might be noticed. Ensure that any of these are dealt with as soon as possible so that when you hand over your final payment you are confident that your kitchen is installed as it should be.
Remember that no guarantee can take away your rights in law.