What Mr Little did tell members attending the party's election year congress in Wellington is speculators are in the firing line to start paying tax.
Overseas speculators would be banned from buying existing houses and Labour would do that in its first 100 days in office.
Second, Labour would make speculators who flipped houses within five years pay tax on their profits.
And Labour would close the tax loophole allowing speculators to claim taxpayer subsidies for their property portfolios.
Speculators could take losses from their rentals and offset those against their personal income, allowing them to avoid paying tax, he said.
''This loophole is effectively a hand-out from taxpayers to speculators. It gives them an unfair advantage over Kiwi families.''
Removing the speculators' tax loophole would save taxpayers $150 million a year once fully implemented, Mr Little said.
However, two Dunedin tax practitioners say the deal is too complicated and unlikely to make much of an impact.
Crowe Howarth Australasia tax advisory managing partner Scott Mason said the introduction of the loan-to-value rules by the Reserve Bank meant most people were probably close to cash break-even on their property investments.
The removal of the depreciation rules five years ago ended the ability to claim tax losses for a nominal loss of value of a property.
Property investors would borrow on a portfolio basis. If Labour changed the rules, they would change their borrowing to a house-by-house basis.
Rent should then cover interest, rates, repairs and maintenance.
''This sounds impressive but it is not as big a deal as they think it is. Once you start tinkering with a comprehensive tax package to fix a problem tax is not designed to fix, you create more compliance.''
It appeared Labour wanted to extend the ''bright line test'' to five years from the current two, Mr Mason said.
The test meant gains from the disposal of residential land acquired and disposed of within two years would be taxable, subject to some exceptions.
For Labour to make speculators flipping houses within five years pay tax would mean identifying the personal circumstances of each individual.
There were already complaints about rents being too high in major centres. Labour's policy would push rents higher, he said.
Deloitte tax partner Phil Stevenson said Labour had targeted landlords but they were no different from any start-up business which could claim back on losses made in the early days.
''The big lever was pulled on this five years ago. Rental property is a business, like anything else. You are going in at the front end with debt. You put the rent up or pay the debt down - you will pay tax at some point.''
Mr Mason said stopping overseas speculators from buying existing
houses would be easier to enforce as it was property law, not tax law.
In his speech, Mr Little said the $150 million in savings would be used in grants for home insulation and heating.
Homeowners and landlords would be able to get up to $2000 towards the cost of upgrading insulation to modern standards or installing heating.
Over a decade, Labour would make 600,000 New Zealand homes warmer, drier and healthier.
''This is a perfect complement to my Health Homes Guarantee Bill that requires rentals to be up to a standard where they are fit to live in.''
Mr Little also reiterated a policy announced early this month which said Labour would build 200 affordable KiwiBuild houses and state houses on unused government-owned land as the first steps to fix Hamilton's housing crisis.
On the same day, Social Housing Minister Amy Adams announced 43 new two-bedroom houses would be built in Hamilton by the end of July.
