Its elliptical pod shape and deck makes the most of the picturesque setting.
"I love waking up there every morning," Mr Walden said.
"I don't even need a watch or a bedside table clock; I can lift my head off the pillow and I can tell by the amount of traffic coming down the bridge what time it is. That's how good it is."
Designed by architect Richard Priest, the second and main floor of the house is where all the action happens.
The open-plan living area takes in the kitchen, dining table and lounge area - with large sliding glass doors ensuring great access to the deck.
"It's the kind of house that loves people. We've had weddings here for 100 people, we've had huge parties, it's a great party house," Mr Walden said. "That bench has been full of champagne flutes. At times, it's been like being in a night club.
"It's modelled on a Sydney home. There are lots of waterfront homes in Sydney that are exactly this - three levels, lots of glass [which] take over the view."
And while the bottom floor features a sauna and a media room as well as two other bedrooms, Mr Walden is adamant all the magic happens in his boatshed by the water.
With its own pull-out bed, bathroom, fridge and deck, there's no need to head to the beach to get away from city life.
"Living down at the boatshed has been a dream. It frees your mind and the ideas flow and it's got a fridge, so you can keep a bottle of champagne there and it's all good," he said.
Some of his best ideas, including ASB's Goldstein ads, were dreamed up there, Mr Walden said.
"It's a bit like having a holiday house at the bottom of your garden."
The house is being marketed by Graham Wall of Graham Wall Real Estate, who said he was confident the luxury property would secure at least $6.5 million.
It has a CV of $4,100,000.
Absolute waterfront
Sarsfield St, Herne Bay
3 levels, all with decks
3 bedrooms, 3 bathrooms
Sauna, separate media room
Self-contained boatshed with pull-out bed, bathroom and fridge.
