From 29 March 2018 the bright-line test for residential property has been extended from 2-years to 5-years. This means any Capital Gains on the sale of your Rental Property (there is a main-home exemption) will be taxed if you buy and sell within a 5 year timeframe. The extended bright-line test only applies to properties for which an agreement to purchase the property was entered into on or after 29 March 2018. If an agreement to purchase a property was entered into before that date, the 2-year bright-line test will still apply.
The residential land withholding tax (RLWT) rules have been extended from 2-years to 5-years as a result of extending the bright-line test. An offshore person will be liable for RLWT on residential land sold within five years of purchase, if the purchase date was on or after 29 March 2018.
It is best to check with us before you make any decisions about buying or selling investment properties and here is a link to where you can read more information from IRD.