What a difference a zone makes. In this case, try $500,000.
Experts say there has always been a difference in price for properties located within the double-grammar zone for Auckland Grammar and Epsom Girls Grammar, but the gap is widening as the city's average house price continues to hit record highs each month.
One Mt Eden home just 750m outside of the area went for $516,000 less than a house just up the road, valued the same but situated 250m within the zone, which cuts off south of Balmoral Rd.
Despite having a section with an extra 230sq m, a slightly bigger house and an extra bathroom, 16a Peary Rd sold for $1.55 million, while 576 Mt Eden Rd sold for $2.066 million.
They were both modern five-bedroom homes and had capital values of just over $1.5 million.
The homes are just 1.1 km or four minutes' drive from each other.
The double-grammar boundaries include part of Epsom and Mt Eden in the south, east to Remuera, up to Mechanics Bay and the area south of Auckland Domain.
Barfoot & Thompson real estate agent George Fong said a couple with two young children had purchased the Mt Eden Rd home. They sold their 1960s home in Epsom, which was already within the zone, as they wanted to enjoy more-modern living but stay in the zone.
The house is one of seven homes located behind a security gate in a new development. Neighbouring properties went for similar prices.
The five-bedroom house at number 580, which had a slightly smaller section than the Peary Rd house but a valuation $90,000 higher, sold for $2.26 millon in June - a difference of $710,000.
Number 578 sold for $2.05 million in July, and 572 sold for $1.89 million in August. Number 574 is currently for sale; tenders close on Tuesday.
"You're only just inside the zone," said Quotable Value valuer Bruce Wiggins.
"It's a lot of money to be paying to live in those sorts of areas."
Mr Wiggins said homes in the mid to high price range located within the double-grammar zone had always been popular.
"It's just that it's become more pronounced. People place a premium on those houses because that area is so small.
"But it's not just the grammar zone. It's certainly a big drawcard for people, but Mt Eden village itself is a very desirable location these days, being close to the city and bus routes and arterial routes. It's a good part of town."
The schools have strict enrolment criteria and require proof of address from parents when considering taking a student.
Epsom Girls demands a power and telephone account from within the past month, a rates demand or sale-and-purchase agreement, or if renting, a bond receipt showing a fixed-term agreement for at least one year.
Both schools have offered ballots for a limited number of out-of-zone places, with priority for children of former students, although Auckland Grammar this year decided not to hold a ballot for 2014 for Years 10-13 "due to pressure on the school roll".