But while the thinking has been under way for some time, Makhlouf agrees that the political push to put it into action does represent something new - possibly a world first.
"This is a bit of a leap of thinking," he says. "In the sense of taking that strand of economics and saying let's start applying it rigorously to decision making, to government policy making, to Budget making. That is different. That hasn't been done before."
There has been a lot of international work done to develop the new framework, or "four capitals" model, he says.
The four capitals are natural, human, social and financial.
"What we've been doing, for the last six years or so, is working up the framework to improve our advice. The new Government has arrived and said: we like this stuff, we want to base our Budget around it, we want to develop a series of indicators. We want to measure our success against it.
"We're probably the first country in the world saying, all this conceptual stuff is great but let's take it and apply it to policy and decision making."
Treasury is now seeking public feedback on the indicators it will decide on - the measures that will define the new policy framework.
"Our objective is to get a number of indicators – not so many that we get overwhelmed – but enough to enable us to make decisions and value judgments," he says. "It's definitely a process of working with the public who is interested, academics who are interested."
Adding each of the new capitals to the policy framework presents its own challenges, Makhlouf says.
Financial (physical) capital
Financial, or physical capital, is the one that now forms the basis of economic policy around most of the world.
Makhlouf wants to reassure critics that Treasury will not be turning its back on the bedrock of fiscal responsibility.
"One of the important things to bear in mind is that the Treasury has not abandoned GDP, it has not abandoned economic growth, it's not abandoned the importance of running the government's books in a sustainable way," he says.
"What we are saying is we need to add some more indicators around our decision making framework."
Natural capital
Natural capital looks like the next easiest thing to integrate into a policy framework, Makhlouf says.
That's because our consideration of environmental impacts in cost-benefit analysis and policy decisions is already well developed.
"When we talk about natural capitals we mean anything from energy to minerals, water. Some of it is about ecosystems and the way they work together," he says.
Makhlouf talks about retaining an "unapologetically pragmatic" approach to environmental costs.
In other words, putting more emphasis on environmental cost and benefits doesn't inherently mean a political shift towards "greenie" values.
Makhlouf accepts that some people will disagree strongly with Treasury's balancing act on environmental issues.
"Putting a price on nature is contentious, but shying away from it misses the point of economic valuation. There are not infinite resources to devote to protecting nature, so hard choices need to be made about using or conserving natural resources," he said in a speech on the topic last month.
In some circumstances a reduction in natural capital may actually be a good thing, he argues. He cites hypothetical tradeoffs such as preserving land versus building new houses.
Human capital
In terms of its difficulty to implement, human capital is third, Makhlouf says.
"It's really about the skills and knowledge that we have," he says.
While it is a new area, there is a lot of work under way about future proofing the workforce, managing the transition to new technology, robots and artificial intelligence in the workplace.
One is a cost-based approach, which aggregates resources used to rear children and provide schooling and healthcare, and then calculates this across time. Then there is an incomes-based approach, which values the stock of human capital based on the incomes earned by each qualification type over the lifetime of people with this qualification.
And then there is an educational stock-based approach, which uses indices of key measures to assess the country's performance (such as years of education, degrees earned and life expectancy).
New Zealand has traditionally focused on the income-based measure – in census data, for example.
"But the approach ignores the value of skills when they are not used to generate an income," the discussion document notes.
It is safe to assume that any new measure of human capital will aim to address this issue, which can lead to undervaluing highly skilled workers – in areas such as nursing or teaching, for example.
"Social capital is more difficult," Makhlouf says. "It means things like trust in institutions, social cohesion, factors like that. How we measure that is going to be harder. But there are social surveys that already try and measure that."
Social also includes cultural capital – so issues such as the Treaty of Waitangi.
In a speech last month on social capital, Makhlouf argued that "the concepts of culture are not taboo for economists".
But this is the area, he concedes, mostly likely to get fiscal purists wound up.
"I do acknowledge that the ideas invoked as part of social capital can seem 'fuzzier' than those traditionally thought of as 'typical' economic policy advice," he said in the speech.
"But the traditional view of economics is more of a caricature than reality."
That seems a harsh criticism of the mainstream economics that have underpinned Treasury advice for many years.
What did he mean by that? the Herald asks.
"It's partly the idea that we live and breathe GDP," he says. "That GDP is the only thing that matters.
"It's partly the idea that has grown up that economics is the same as its macro-economic models that assume perfection, that assume efficient markets, that assume everything works perfectly."
Economics is much more than macro-economics, he argues.
In fact, he suggests, if you go back to the 1940s when GDP as a concept was relatively new, even the guy who invented it, Simon Kuznets, was cautious and warned that it can't measure everything.
"We're certainly breaking new ground if you took economics as starting 20-odd years ago. On the other hand, some of the thinking we're doing is actually in the core tradition," he says.
Makhlouf cites Adam Smith – considered by many to be the father of the discipline – and John Maynard Keynes.
"This is the sense that economics is a human science. It's not like physics."
What next?
So, what next? How does Treasury get these ideas into the black and white of the Budget in time for May 2019?
Makhlouf admits it is a challenge, but it seems to be one he is relishing.
By the end of the year he hopes Treasury will be ready to publish a set of indicators that will reflect "where we stand on all four capitals".
"The theory at the moment is that Treasury will – probably at Budget time each year – publish a report that sets out how we're doing on the capitals – what is the state of the capitals, how have they changed? In the same way that every Budget, the Treasury publishes an economic forecast and a fiscal forecast.
"I'm pretty persuaded that we will be able to publish a series of indicators. At the same time I'm pretty clear myself that they are unlikely to be perfect. This will be a process where we will be iterating and learning and improving.
"Economics is about tradeoffs," he says. "Economics is about the fact that there are finite resources to meet unlimited wants and what's the best way of dealing with that problem.
"What the Treasury is suggesting now is that we can become a bit more sophisticated than in the past at making those tradeoffs."
The critic
"The problem for me is that we don't really know what it means yet," says economist Eric Crampton of the Treasury's bold new plans for a living standards framework and a wellbeing Budget.
Crampton, chief economist with think tank The New Zealand Initiative, is one of many within the profession who have raised doubts about the value of broadening the focus of policy setting, beyond purely fiscal measures.
"If the living standards framework is a way of reminding people they need to be thinking about environmental effects, or other similar kinds of issues that might have been forgotten in a cost-benefit assessment ... that would be all fine," he says. "But my worry is that it won't go that way."
Crampton says his concern is about the practical realities of decision making by government ministers.
"The risk is that having a dashboard of too many indicators, where they are estimated with varying levels of stringency, there will be a temptation by some to focus on the indicators to put their policy in a positive light."
In other words, the range of indicators will give governments wiggle room to put less emphasis on indicators that might put their policy in a negative light.
He also has concerns about Treasury resourcing and its capacity to deliver a robust analysis across "the four capitals".
Crampton acknowledges criticisms of GDP as a measure of wellbeing but remains a defender of its value – and of a monetary basis to cost-benefit analysis.
"GDP has often been a pretty good proxy for what's going on in a country," he says. "It's not about money - it's about trying to figure out if something is worthwhile or not and makes people better off.
"We conceptualise that as a common unit of exchange. If there's some project that might have a way of making an area better off, but might have some environmental cost, we need to find a way of trading those off against each other and the language of money is usually the one that puts things on a common basis."
Crampton accepts Treasury's work on living standards and wellbeing pre-dates the current Government.
"I think that it goes back to 2005 when Michael Cullen dismissed some Treasury advice, saying that it was just an 'ideological burp'.
"Treasury has been terrified of being in that spot again – where a Government just wouldn't listen to it. Under the prior National Government they started building this new measure in expectation of a change in government.
"I hope that they don't do it at the cost of the rigour around cost-benefit analysis."