Ten beachfront property owners in Sydney’s north said they have had to stump up $280,000 each to fund a $25 million seawall that will protect their houses from collapsing into the ocean.

The state government and council are together tipping in 20 per cent of the costs for the construction of a wall stretching from Collaroy to South Narrabeen after heavy surf and powerful storms put them at risk of being washed away.

Now there’s an additional $300,000 in engineering and legal fees, which resident Bob Orth thinks someone else should pay.

Mr Orth’s beachfront property at Collaroy was almost washed away in the 2016 storms.

However he said footing the additional costs would not be easy for residents.

In fact, some residents have had to dip into their superannuation.

“It’s not a rich list here, it’s a lot of different family people who have had to come up with $300,000,” Mr Orth told 9News.

“At the moment the contribution from state [government] and council is only based on construction, which is once you physically start building the wall. Prior to that, there’s a lot of costs [such as engineer and legal fees].

“We believe at the very least that cost should be taken into account in the contribution of the state and the council.”

Mr Orth argued the wall was not just being build to protect the multi-million dollar homes, which made it unfair for residents to have to fork out so much for it.

He said the wall will also protect the streets behind the beachfront strip, including Pittwater Road.

“If this wasn’t built, come a couple of storms like we had in June 2016, there won’t be Pittwater Road, there won’t be sewage, there won’t be telephone lines, data cables, all the services… let alone a road.”

He said there’s a considerable benefit to other locals for the 1.3 kilometre barrier to be built on beachfront residents land.

“It’s private land this wall is built on but it’s going to have a big public benefit,” he said.

Despite the cost, Mr Orth said the erection of the wall is a “great relief”, with the area at constant risk when wild weather whipped up.

“It’s taken a long time but we’re really pleased with it and the progress we’ve made.”

The damaged multimillion-dollar beachfront properties were left teetering on the eroded coastline since violent storms lashed the coast in 2016.

Residents were forced into emergency accommodation while damage was assessed, with sandbags used to stabilise the area.