That's how Jim Johns and Rachael Sweeney have lived for 27 years in their 50-acre, waterfront Batemans Bay home.

The off-grid South Coast estate is for sale by expressions of interest, with a price guide of $5 million.

The couple, who previously owned a series of McDonald's franchises throughout NSW, are reluctantly selling the property due to a change in circumstances.

Their love for the home is steadfast.

"There's a river in the front, a mountain at the back, it faces the sun in the morning. If there is such a thing as perfect feng shui, it's got it," Mr Johns said.

"It's an amazing lifestyle and we're not going to be able to duplicate that again.

"Just the fact that it's in the middle of a national park really makes it special because you don't have neighbours, you've got all of the natural surrounds ... it's secluded but it's very close to town," Ms Sweeney said.

Mr Johns and Ms Sweeney are only the second owners of the large parcel of land. The first was a World War II commander who was granted the block in 1945.

"It's the only house in the [Clyde River] National Park, effectively," he said.

Local firm I Architecture designed the home that exists today, extending on the foundations of the original property. It now boasts four bedrooms, three bathrooms and soaring cathedral ceilings.

Designed with alfresco entertaining in mind, the property includes decked dining spaces, a full outdoor kitchen, a swimming pool and five acres of landscaped gardens. An old quarry remains on the property, while a natural, deep-water boat ramp offers direct access into the Clyde River.

Electricity bills would be a thing of the past for the new owners, as the house is completely self-sufficient with a seven-kilowatt solar system.

"The dam on the property is 12 megalitres, which means lots and lots of water," Mr Johns said.

With its multi-million-dollar price guide, the house is expected to smash the current sale record for the suburb, and much of the region.

The record price for Batemans Bay is currently held by a penthouse apartment, which sold for $1.45 million in 2019.

Recent top sales in the South Coast include $3.35 million for a waterfront house in Mossy Point, a Surfside property for $2.47 million and a recent record sale in Broulee for $2.95 million.

The campaign is being marketed by Sydney Sotheby's International Realty and Ray White Batemans Bay.

Harriet France of Sydney Sotheby's International Realty said the property was likely to appeal to anyone seeking a private, coastal lifestyle.

"To own 50 acres of waterfront living in Batemans Bay - there's nothing comparable," she said.

"It's almost like owning your own private island."

The couple were emotional about the prospect of leaving their home, but hopeful the next owner would appreciate the lifestyle it has afforded them for almost 30 years.