But in a modern take on Upstairs, Downstairs or Downton Abbey, a mini-city under the main residence has rooms within rooms, services on a par with any commercial venture, hidden corridors running the length of the main swimming pool, metres of ducting, pipes and underground corridors ensuring the main residence's comfort levels of air handling, fire safety, IT, kitchen services, heating and cooling are top-notch.
This is no simple house: for a start, one tower crane and a crawler crane worked alongside each other for years. Some construction crew have been on-site for five years, many members of local iwi Ngati Wai worked on the property and seven people started and completed their trade apprenticeships on this job alone.
Russian steel billionaire Alexander Abramov
At about 2500sq m, the main U-shaped lodge of Russian steel billionaire Alexander Abramov is 10 times the size of the average new Kiwi house, but the entire subterranean floor has services so sophisticated that they make your average commercial building look positively shoddy.
Visitors can helicopter on to the property but those who drive to this "bach" fit for a tsar will enter the gateway faced in Portland's Paradise Stone before travelling the many kilometres of winding internal roadways flanked by flowering flax, blazing pohutukawa and renga renga.
The overall effect is of lushness, passing streams, valleys, waterfalls and new lakes where endangered species including the pateke (brown teal) duck and kiwi are to breed, past new timber rail fences, pine forests, hills of cabbage trees and ferns and extensive stands of native bush.
Extensive predator control measures, including trapping and poisoning possums, weasels and stoats, have nurtured natives like pohutukawa and 240,000 new plants are now on this private 214ha estate. Stock fencing prevents animals getting near waterways.
Around a bend at the foot of the valley as the ocean looms up, two low bitumen roof tile structures appear: a mini power station with a grunty 600KVA diesel generator housed in its soundproof building, able to supply the property indefinitely during a power cut, and a construction site office, to become a gatehouse or reception welcoming area in the next few months.
Then, four grand structures become visible: the main lodge or principal residence and the villas perched above, all on the ocean front, colonial-style structures in neutral palettes topped with grey asphalt roof tiles.
A porte cochere entranceway protects guests and marks the end of the drive from Auckland to the property, off Russell Rd.
The property has been developed by Helena Bay Holdings managing director Christopher Seel, who said it would open next summer. "The jewel in the crown is the amount of detail and it's the choice of the owner," said Mr Seel, an engineer and banker of Coatesville. Originally from Pukekohe, he worked in Moscow for many years where he was linked to Mr Abramov, whose international steel business Evraz employs 110,000 people.
What has never been revealed until now is that Helena Bay is to be run as a luxury resort, along the same lines as Northland's Kauri Cliffs, the Wairarapa's Wharekauhau and Glenorchy's Blanket Bay.
"We look forward to joining the well-established and highly awarded luxury lodge sector and we hope to offer a unique experience, not commonly provided or seldom found in a single lodge, spanning beach, farming, fishing, ecology, environmental, historical and archaeological elements," Mr Seel said. "It's also Helena Bay's proximity to Auckland which gives it that unique edge."
Mr Seel could not comment on an estimated $50 million price tag but the expanse of the property and the quality of the finish are thought to put it in that bracket.
Helena Bay
• $50m+ of new residential buildings
• Own mini power station
• Vast upstairs/downstairs kitchen areas
• Main four-bedroom guest hilltop residence
• Three separate luxuary waterfront villas of about 500sq m
• Two villas can be divided into four residencies
• Opening 2015/16 as top-end luxury lodge