The Ministry for the Environment's guidelines to private plan changes said it could be a time-consuming and costly process. It usually takes from six months to a year but it could take as long as three years.
The ministry said costs ranged from a minimum of $10,000 to $1 million for large-scale developments while average costs were around $30,000 to $50,000 for a rural residential subdivision with minimal opposition.
Hastings City Business Association opposed Charter Hall's request for smaller shops because it believed it would provide direct competition with its retailers in the CBD.
General manager Jane Janes said retailers continued to show strong and unanimous support against Charter Hall's plan and it would oppose any new application from the retail firm, seeking smaller shops in the Mega Centre.
"We hope that Charter Hall do not proceed with any further options," she said. "The key issue remains central to the opposition in that it is imperative the ongoing economic and social viability and vibrancy of our Hastings CBD is protected at all costs."
In November, Charter Hall said while larger big-box retailing was popular when it bought the former Nelson Park site on Karamu Rd in 2008, now fewer retailers wanted to operate from such large floor space.
It said smaller tenancies would result in a retail centre that had stronger regional pull, maximising the economic benefits for the city. It claimed money that might be spent at the Mega Centre would be the same whether it had 1000sq m stores or 500sq m stores.