The advice comes from the Dunedin City Council after it completed an initial inquiry into the collapse.
Eighteen people were injured when the deck collapsed at a Six60 concert in Castle St on Friday.
University of Otago student Bailley Unahi (19) is in Burwood Hospital with serious spinal injuries after the incident.
Otago Polytechnic student George Karamaena (18) is in Dunedin Hospital with two broken legs and a broken back.
Council services and development general manager Simon Pickford said an engineer had examined the scene and the balcony and found ‘‘nothing of concern for the way it was built''.
‘‘When we look at the way the beams broke, it did indicate a sudden failure brought on by an overload,'' Mr Pickford said.
A letter, which provided initial findings, had been sent to the flat owner, Mr Pickford said.
The owner had been advised to strengthen other balconies using extra bolts, fixings and joists.
Tenants had been instructed to keep off them until strengthening was carried out.
‘‘That's really just a prudent thing to do at this stage,'' Mr Pickford said.
‘‘All we're concerned about is that the balcony meets code and it does.''
The balconies were cantilevered to allow for car parking.
The council had considered suggesting the owner put in ground supports, but it was not necessary as the plans met code requirements, he said.
‘‘The balcony owner could take independent engineering advice.''
Dunedin Mayor Dave Cull said he understood the Ministry of Business, Innovation and Employment was investigating the Castle St collapse alongside the DCC.
‘‘Our chief building inspector, Neil McLeod, visited the site at 8am on Saturday morning. He ascertained that, as far as he was concerned, it [the deck] was built to code.'' Mr Cull said the collapsed deck would be tested.
‘‘[Mr McLeod] is assisting MBIE and ... they will also be looking, I assume, at the records of the consent at the time.''
An MBIE spokesman said in a statement the ministry was working with the council and it expected to receive a preliminary report on the collapse by the end of the month.
