With more than one in four Victorians now renting a home, the Andrews government will on Sunday unveil a raft of changes giving tenants more rights while cracking down on unscrupulous landlords.

Under the plan, agents will be required to advertise properties using a single price - rather than a range - and landlords will be restricted to increasing rent once every year instead of every six months.

They will also need a reason to end a tenancy - with the government scrapping the 120-day "no specified reason" notice to vacate - and will not be allowed to unreasonably refuse a tenants' request to keep pets or make minor modifications, such as installing airconditioning or picture hooks.

"More people are renting than ever before and for longer - that's why tenants need a fairer deal," said Consumer Affairs Minister Marlene Kairouz.

The changes come after a lengthy review of the Residential Tenancies Act but are likely to prove controversial because they swing so heavily in favour of tenants.

While welfare groups and renters have welcomed a fairer deal, the Real Estate Institute of Victoria has warned that many of the reforms would unfairly penalise "mum and dad" investors who make up the bulk of landlords.

"What the government has failed to understand is that it is imperative that any future legislation balances the rights of all stakeholders - any imbalance in the market has the ability to cause a rental crisis," said REIV chief executive Gil King.

"The majority of Victoria's landlords are 'mum and dad' investors who are looking to fund themselves in retirement. Victorian landlords should be alarmed at the piecemeal introduction of these reforms by the government."

As part of the 14-point policy, the government will also announce:

• Landlords will not be able to charge a bond worth more than one month's rent for any property where the rent is less than double the weekly median (that is, less than $760).
• When a tenant is out of pocket for undertaking urgent repairs, landlords will be required to reimburse them within seven days instead of 14 days.
• Tenants will be allowed to apply for their bond without agreement from the other party, and if no dispute is lodged within 14 days the money will be automatically released.
• A new Commissioner for Residential Tenancies will be appointed and, as reported by Fairfax Media on Friday, landlords will be banned from soliciting rental bids from prospective tenants and could be named-and-shamed on a public blacklist. Landlords will also be required to provide vital information before tenants sign on the dotted line, such as any plans to sell the property or any known asbestos hazards.

The reforms come as the government's latest housing figures show that the median weekly rental price is $400 in Melbourne and $290 in regional Victoria. But only 6.6 per cent of homes in Melbourne are regarded as affordable for low income earners - a stark contrast to 30 per cent a decade ago.

Nicole Rees, senior manager of public policy for the Brotherhood of St Laurence, said the government's measures would have a "real and significant impact" on tenants, many of whom "are renting for the long haul now - and many will be renting for the rest of their lives".

While it wouldn't solve the broader problem of housing affordability, she said, "it will remove some of the stress and give renters a greater sense of security and confidence".

Jesuit Social Services chief executive Julie Edwards said she welcomed the reforms, but urged the government to also improve public and social housing supply to ensure more people could have a home.