Homes owned by Auckland's electorate politicians have leapt more than $14 million in value in just a few years, highlighting how the city's 23 local MPs have benefited from the housing market boom.
Prime Minister Jacinda Ardern's Sandringham home in inner Auckland jumped $1.08m in three years.
Opposition leader Christopher Luxon's portfolio of properties rose at least $3.1m.
Former National leader Judith Collins holds the second best-performing portfolio - after Luxon - the three homes she holds an ownership share in collectively jumped $2.2m.
Deborah Russell, the Labour MP for New Lynn, enjoyed the second biggest equity gain among Labour MPs as her Titirangi home in Auckland and her Karori property in Wellington rose a combined $865,000 in three years.
Chloe Swarbrick - the Green Party's only electorate MP who holds the Auckland Central seat - is yet to make an equity gain on her property, according to Auckland Council's CV data.
That's partly because her Auckland Central apartment is a new-build and therefore wasn't valued in 2017.
It's also because Swarbrick paid $1.42m for the apartment in 2020 but Auckland Council valued it at $1.36m last year - less than what the Auckland Central MP bought it for.
Overall, the 35 properties the Herald could trace as being owned by the 23 Auckland politicians who hold electorate seats in Parliament jumped a collective $14m in total.
The figure is an underestimate because the Herald has not been able to track every property the electorate politicians own.
National leader Luxon declared an interest in three residential homes and four investment properties in his official statement to Parliament's Pecuniary Interest register.
However, the Herald has only listed six of his properties here.
Similarly, National's Mark Mitchell - the MP for Whangaparāoa - declared an interest in six properties, but only three are listed here.
Labour MPs Aupito Sio, Jenny Salesa and Neru Leavasa also declared ownership of properties not listed here.
Act MP David Seymour is the only Auckland electorate MP who doesn't have an ownership share in any homes.
However, Seymour has previously admitted he could inherit properties or parts of properties from his grandparents and father.
The Herald research is based on Auckland Council's recent release of new valuations for every property in the city.
The Herald calculated how much the MP's properties have increased in value by comparing their most recent Auckland Council CV against the previous CV released in 2017.
For properties the politicians own outside Auckland, the Herald used CV data released by the council in that district.
It should be noted that although the $14m rise in value sounds like a windfall, it hasn't all gone straight into the politicians' pockets.
In many cases, the MPs do not own the homes outright and instead share ownership with family or business partners.
And while the Herald has in most cases calculated the rise in value of the homes since 2017, the politicians may not have owned the properties for this entire period, as some only bought their properties recently.
Nevertheless, the electorate MPs have still enjoyed impressive gains.
Luxon enjoyed the biggest rise in value for a single property: his $6.8m luxury Remuera home has jumped $1.5m in value since 2017.
The 1930s-built bungalow features six bedrooms and an 1100sq m block.
Overall, Luxon's six properties are worth a combined $12.6m.
Former National leader Collins had the next biggest jump: her $4.8m St Heliers home rose $1.45m in value.
Ardern's $1.1m gain on her Sandringham home was the third biggest jump in value.
Her house is now worth $2.9m.
National's Andrew Bayly - the MP for Port Waikato - recently cashed in on the rise in value of his six-bedroom Karaka home by selling the luxury "colonial masterpiece" home last month for an undisclosed price.
It sits on a 6.5ha lifestyle block and features a swimming pool, lake and games room, according to its Barfoot & Thompson real estate advertisement.
Auckland Council valued the home at $3m in June 2021, a $675,000 jump in value since 2017.
Chris Penk - National MP for Kaipara ki Mahurangi - also sold a Mt Maunganui investment property in December last year for an undisclosed price.
The flat had been valued at $785,000 in its most recent council valuation.
Members of New Zealand's Parliament are required to give statements in the Pecuniary Interest register, declaring what homes, assets and other financial interests they own.
This is designed "to promote greater transparency, openness, and accountability in the parliamentary process", by allowing voters to see the financial interests of the MPs.
"It ought to strengthen public trust and confidence in the integrity of members of Parliament," top watchdog, the Office of the Auditor-General, says about the register.
"The register will be a useful tool to help identify and avoid possible conflicts of interest."
Many politicians state exactly how many homes and investment properties they own and in which suburb they are.
Some give more general statements, including former National leader Collins.
Her statement says she owns an Auckland family home and an undisclosed number of commercial and residential property in Wellington and Auckland.
She also says she owns property in Nelson.
However, public records link Collins to up to 10 properties, including homes in Hamilton, the Rotorua district, Invercargill and Southland.
These properties are not directly listed in the register.
A spokeswoman for the National Party says Collins owns only three properties.
For the other properties, she is acting as what is known as a "bare trustee and has no beneficial interest in them", the spokeswoman says.
Simon O'Connor - the National MP for the Tamaki electorate - declares a beneficial interest in two properties.
But, like some other politicians, he does not declare an interest in multiple properties owned or part owned in his wife's name.
It's not just politicians, who have benefited from the housing boom.
Ordinary Auckland home owners' property values have skyrocketed; the average house value has risen $338,000 - or 32 per cent - in four years between 2017 and 2021.
Swarbrick is the only politician to give a statement to the Herald, saying she and her partner had been "fortunate enough to buy our apartment around a year ago - this is our home".
"We are all acutely aware that this is a privilege not afforded to an increasing number of New Zealanders," she said.
"That is why the Greens continue to push for taxes on accumulated wealth, rental warrant of fitness and rent controls. As we've been saying for years, house prices must fall to affordable levels, which means three to five times the average income."