Mr Thompson said the firm was donating $500,000 towards a $12 million completion of the Holy Trinity Cathedral in Parnell and increasing this year's Starship donation from $200,000 to $500,000.
"We are delighted to be part of the cathedral project ... and you can't talk enough of what doctors and nurses do for the future of Auckland and New Zealand," he said.
The Starship donation would be fundraised during the year by the firm's branches through events such as trivia quiz nights, barbecues and meat raffles. The money will go towards three incubators and upgrading a family garden area.
Auckland Mayor Len Brown, who attended the firm's celebrations, praised the magnitude and significance of the civic gift.
"Barfoot & Thompson's desire to mark 90 years of business success and support for Auckland by giving something back to the city and its people is awesome," he said.
In 1923, Val Barfoot purchased a run-down land agency in Newmarket for £75 ($150). He was joined by his brother a year later and in 1934 by Maurice Thompson. The firm has grown to 63 branches with more than 1300 sales staff.
City gift
• $1m - sculpture on Queens Wharf
• $500,000 - donation to Holy Trinity Church
• $500,000 - donation to Starship Foundation