New figures provided in the ACT budget reveal ratepayers in the Gungahlin area will see the largest percentage changes (9 per cent for houses and 12 per cent for units) while Weston Creek will see the smallest (5 per cent for houses and 9per cent for units).

Rates for detached homeowners will rise 7 per cent on average for the coming year, or about $172, to an average of $2474, while unit owners face a 10 per cent, or $135 rise on average, to $1472.

Unit owners will also lose the one-off $100 rebate after last year’s change in rates calculation, but the increases to marginal rates have been tempered this year to soften the rise.

However to give unit owners more time to adapt changes in the way their rates were calculated in last year's budget, the government said it would extend the transition to the new methodology for another year.

This year, properties with an average unimproved value of more than $600,001 will see a change to their rating factor, from 0.6013 to 0.57.

Those in the 0 to $150,000 bracket will see their marginal rates percentage go from 0.296 to 0.313.

A Treasury spokeswoman said the extended transition would mean a "tighter distribution" of rates rises, meaning more people would see increases of 10 per cent and fewer would see the massive hikes of 45 per cent like last year.

Modelling from Treasury shows just 99 units will see general rates increases of more than 25 per cent while 7000 will see an increase of 9-10 per cent.

The spokeswoman said the extension of the transition would mean the government would sacrifice around some rates revenue this year, although the rates intake was growing.

She said the rates reform would return to its original trajectory next financial year.

However unit owners will lose the $100 rebate from last year's budget, and all ratepayers will lose access to the early payment discount from July 1.

The government has been phasing out the discount since the 2016-17 budget.

Around a quarter of ACT households received the discount, but with average rates at about $2400, the discount was only about $25, the Treasury spokeswoman said.

The change will save $1.4 million this financial year, and $6.4 million over forward estimates.

However the government has extended the aged deferral scheme for general rates by removing income and unimproved land thresholds. Now all property owners aged over 65 years can defer their rates until the sale of their property, a measure expected to cost $50,000 this year.

The Barr government will also abolish the first home owners grant to cut stamp duty for first home buyers in the ACT from next July.

It will also scrap the early payment discount for ratepayers, as rates rise by up to $200 for two-thirds of homeowners across Canberra.

From July 1 2019, first home buyers with a household income below $160,000 will pay no stamp duty, regardless of whether they buy a newly built or established home.

At the same time, the government will dump the $7000 grant for first-home buyers.

Previously, first-home buyers buying new and off-the-plan properties have been able to access both the grant and the home buyer concession scheme, which provided a discount on stamp duty for people buying new or substantially renovated residential home or residential vacant land.

Based on an average of figures from the last three financial years, about 1000 homebuyers a year will be worse off due to the change.

However, Treasurer Andrew Barr said a range of experts had found the grants had not been effective in helping first-home buyers enter the market and had driven up house prices, and there would be a year-long transition to minimise the number of people adversely affected.

"To be honest it has been a first home sellers grant, not a first home buyers grant because the benefit has gone to those selling homes in that segment of the market," Mr Barr said.

"My expectation of what this will do after the one-year transition is it will open up first home buyers to range of supports they previously weren't able to buy in with government assistance, it will out some downward pressure on the demand-side that has been fuelled into a pretty small segment of market supply and importantly it achieves another step closer to our ultimate goal which is the abolition of stamp duty."

The measure will cost $1.3 million next financial year and $3.4 million over the forward estimates.

Stamp duty will fall about $1000 to about $23,700 for the median house price of $753,000, although stamp duty revenue all up will rise to $209 million, from $178 million last year.

The government will also dump stamp duty for commercial transactions for properties worth under $1.5 million from this July.

The change is expected to affect more than 70 per cent of commercial transactions.

The abolition of stamp duty is part of the ACT's 20-year tax reform, where the "inefficient" stamp duty is rolled back in favour of higher rates and land taxation.

An earlier version of this article omitted the change in marginal rates for those in the $0-$150,000 average unimproved value threshold.