Extensive building and excavation work at a property in central Auckland has been shut down by authorities after it was found not to have consent.

Owners of the home on Third Ave in Kingsland begun work late last month, telling neighbours they were doing "a small renovation" - but after trucks arrived, and diggers began doing major earthworks, questions started to arise.

Images of the property show work to the lower level of a two-storey house. Three props held up the upper level, while earthworks had begun on a new foundation.

The property owners, who wished to remain anonymous, told the Herald they had decided to renovate the basement, but didn't realise work was "going to be that huge".

"We were just going to tidy it up," they said.

Neighbours Paula Lockett and Brian Malone said when contractors started removing a lot of soil and putting in a concrete pad - they started to get concerned.

Lockett contacted Auckland Council on August 27, and then again on August 29 after not hearing anything.

Images of the unconsented earthworks at a Kingsland property show work to the lower level of a two-storey house. Photo / Jason Oxenham

"I rang the council because when they were removing the soil, the digging was making our house shake and rattling our windows. It was like booming noises," she said.

When the council failed to respond, John Holley, who lives nearby, contacted WorkSafe.

"I saw contractors come in, start knocking things over, concreting, putting in a new driveway and doing water works.

"The real concerns kicked in when they started doing the excavation - because literally at one point they had two diggers under the house."

Holley said the council initially said they would respond in 5-10 working days, which he felt was insufficient.

"It sounded like I needed to have actually said someone is about to die before they would send someone out, so last Monday I logged the job with WorkSafe and by 2pm they were there and putting the prohibition notice on the site - as it was obvious how dangerous it was."

Lockett said she now feared for the safety of her own property, because they are the closest neighbour and the house is above them.

Excavation work done at the Third Ave property in Kingsland, as of September 1. Photo / John Holley

However, she had not received any confirmation from the council on whether they had anything to worry about.

"We are completely frustrated. I don't consider we have been adequately informed, and question whether we should even be here," she said.

Locketts partner Brian Malone said they'd been told by their insurance company that they wouldn't be covered if the neighbouring property was to cause damage to theirs. Instead, they would have to sue the owners for damages.

"I don't blame the property owners, I blame the council more - because they could have stopped it in the first place," he said.

The couple are working on lodging a formal complaint with Auckland Council, he said.

Since last Monday, Holley said work had been done to make the site safer, however, he was also concerned about the risks.

"It's so close to Paula's house, and is at a higher elevation, so if it collapsed it would go through their walls," he said.

"The concerning thing too is the council have a graduated response, but if the place is dangerous then it needs to be fixed immediately as there are lives at risk."

Neighbour John Holley said he had concerns about the initial bracing that held up the upper level of the house. Photo / John Holley

A WorkSafe spokesperson said it was notified of renovation work being carried out at the property on Third Ave earlier this month.

"After visiting the site, WorkSafe issued a Prohibition Notice which prohibited excavation work taking place at the site until the structural integrity of the building was secured. The notice remains in place.

"WorkSafe is working closely with Auckland Council and engineers to ensure the building is stabilised and the property is safe."

Auckland Council manager of regulatory compliance Steve Pearce said it had also received two complaints.

"We inspected the site on Monday and Tuesday [last week] and found building work underway without building and resource consent. We sought advice from structural engineers, who inspected the site and advised that it wasn't safe," he said.

"As a result, we have issued a dangerous building notice requiring the site be fenced off and to undertake work to make the building safe."

Pearce said this work had already commenced and was under regular engineering supervision.

"While the immediate danger has passed and is being dealt with, we continue to have an open investigation into the illegal building work.

"The council has a graduated enforcement approach, this means we work with people to fix problems in the first instance but will also escalate to significant formal enforcement action if the effects of non-compliance are serious or the offender has continued to ignore the requirements."

Pearce said when neighbouring properties to a dangerous building are deemed affected, they have the option to issue notices to the owners of the affected buildings.

"However in this instance we do not believe this is necessary based on the level of risk and the advice from the engineers working on the site," he said.

"We have had several conversations with the neighbour concerned, including visiting the address directly after the dangerous building notice was issued and will continue to keep them informed."

The property owners said they were in the middle of fixing the site and a dangerous building report would be completed in the next few days.

On Tuesday engineers from both Geotech and Fraser Thomas Ltd were working at the site.

"We just want to get it fixed, then we will seek consent and make sure we go through the right process," the owners said.

They said they had not been approached directly by neighbours about concerns.

• If anyone is planning to do any work on their property, then they should check the Auckland Council website first to ensure they have the relevant consents needed.