Trends in the city are showing that many residents are opting to us their granny flats, or detached flats, for keeping their loved ones close as they become more reliant on care or choosing to give their children more independence.

Others are choosing to rent out their granny flats to achieve a dual income on their investment property.

Wagga resident Darren Taylor has an investment property, with a three-bedroom share house at the front and a studio detached flat to the rear of the property.

"The granny flat was already existing when we bought the property and it's a fully self-contained, open-plan space with the bedroom and kitchen and then a separate bathroom and laundry space," Mr Taylor said.

"It was just a bonus with the property and I'd recommend them because it works really well for us.

"We rent the main house as a shared house and by the rooms and then the granny flat is also a rental and that's where the caretaker lives."

The granny flat is located behind a Trail Street property and gives Mr Taylor a dual income stream.

"It provides everything we need for our rental and it provides the caretaker space for himself," he said.

Independent property valuer Chris Egan said granny flats pose a number of benefits.

"We're seeing more new homes designed with granny flats as part of overall architectural plans to look after elderly parents as much as possible before putting them in aged care facilities," he said.

"As families age, that component of the property can also be utilised for privacy for teenage children or parents who are conscious of children gaining their independence.

"They're really good income streams for people and also the Airbnb connection for fully furnished, short term stays have become really popular in regional and metro areas."

Mr Egan said it could also be a means of providing more affordable long-term housing.

CoreLogic data revealed there are 3830 properties in Wagga that are zoned for granny flats, with 299 of them which could fit a granny flat.

The data found that these detached flats could boost home values by 30 per cent and add about 27 per cent to rental income.

Professionals Real Estate agent Paul Irvine said granny flats add a lot of value to properties for a number of reasons.

"The cost of going into a nursing home is a factor and moving into a flat behind is a lot more affordable," he said.

"We're seeing this with inquiry from buyers and they're also a great investment.

"If you have a three-bedroom main house and then a granny flat at the back, that's a dual income and it's very attractive to investors who buy one property with two sources of income."

However, Mr Irvine said not all areas in Wagga can allow for granny flats, but said the attraction is mainly for investors.

"For example, there is a covenant in place in Springvale where dual occupancies, like granny flats, are not allowed," he said.

"Older suburbs like Lake Albert, Kooringal, parts of Glenfield and Central would allow granny flats because they're under an old property covenant.

"People are very restricted on where granny flats can be built now."

Wagga City Council said they do not have specific data that shows how many granny flats there are in the city.

Manager city development Paul O'Brien said a granny flat, or a secondary dwelling, is a self-contained accommodation within, attached or separate to an individual home.

"Secondary dwellings are permitted with consent under the provisions of the Wagga Local Environmental Plan 2010 in most residential zones, including the R1, R3 and R5 zones," Mr O'Brien said.

"Council or an accredited certifier can also certify granny flats as complying development without the need for a development application, provided they meet specific standards in the State Environmental Planning Policy.

"Granny flats are promoted by council and the NSW government to provide affordable housing for immediate family and other relatives. It also provides the opportunity to generate income if rented out."

Mr O'Brien said Springvale is predominantly zoned R5 Large Lot Residential and therefore dual occupancies and secondary dwellings are permitted subject to development consent.

According to the data, constructing a two-bedroom granny flat would require an initial investment of about $200,000, while a one-bedroom dwelling would be approximately $120,000.

A granny flat typically rents out for less than the price of a standard apartment, making it an attractive and affordable option for renters on a budget.

"Many home-owners are sitting on a pot of gold in the form of excess land that could be developed to generate a new income stream," said co-founder of Australia property startup Achistar.

This has wider economic benefits for renters who want to access popular suburbs without paying a premium."

"The family benefits of a secondary residency can't be overlooked, whether that's giving adult children more privacy while they save for a mortgage, keeping loved ones close as they become more reliant on care or having additional accommodation for overseas visitors."

Capitalising on this potential for 299 additional dwellings, that was identified by CoreLogic, could also deliver far reaching economic and social benefits, such as greater employment opportunities for builders and other tradespeople.