Prestige Property: 3804/439 Collins Street, Melbourne VIC

Spread over two dramatic levels inside Melbourne’s landmark residence, the Collins Arch, comes the luxurious ‘Penthouse 3804’.

Located in the centre of Melbourne’s CBD, the penthouse arrives with 371.5sqm of internal living and a further 113.5sqm located on the external terrace. Throughout the 3-bedroom, 3-bathroom, 4-car garage residence, full-height windows take in the views of Melbourne’s skyline, with the accommodation arranged to maximise the availability of natural light.

With the interiors designed by Woods Bagot, the penthouse sees the use of ambient natural stone, oak flooring underfoot, brushed nickel finishes and custom joinery throughout.

Entering through the lower-level formal entry, complete with private lift, the penthouse extends to a formal living area with the aforementioned north-facing views of Melbourne’s skyline alongside heady swathe of built-in cabinetry and a marble fireplace.

Taking the spiral staircase, which is carved from marbled stone (no-less), sees one arrive at the primary upper-level living.

The residences upper level is split into two distinct pods. Here, the bedrooms encompass the entire eastern wing of level 39. The master suite offers commanding views and direct terrace access alongside further bespoke cabinetry and decadent ensuite. There is a further two bedrooms found here.

Elsewhere, the intelligently zoned living areas features a beautifully appointed kitchen complete with a Cote d’Azure marble used for the splashback and island bench alongside a butler’s pantry.

Marble also adorns the bathrooms throughout the residence while feature lighting is understood to be sourced from local brands, with bathroom feature lights from Articolo and kitchen pendant by Rakumba.

There are perks to being on the top, with the Arch privy to a three-level atrium style rooftop skygarden atop the building – which the penthouse has direct access to.

Further mod-cons within the $1.2 billion build include a 25-metre swimming pool, gym, yoga room, wine cellar, entertaining lounge and terrace (not that you’ll need that), and two private dining or conference rooms.

Located in the heart of the CBD, there is unsurpassable connectivity to the city and its surrounds.

The listing is with Colliers Sam Nathan (+61 4 075 552 922), price guide $7.85m; collinsarch3804.com.au

For years, tech entrepreneur Asher Waldfogel and his wife, Helyn MacLean, dreamed of building a modern house in Palo Alto, Calif.

The couple, however, worried about clashing with the Mediterranean-style architecture typically associated with their neighborhood of Old Palo Alto.

So they tapped architect Steven Ehrlich to create a design that paid homage to its surroundings with stucco, mahogany and titanium zinc cladding. They spent $20 million over several years building the house, completed in 2005.

Designed for indoor-outdoor living, the house has matching mahogany paneling and limestone both inside and out. Arthur Sharif/Sotheby’s International Realty

The dining room is between an outdoor garden and the staircase. Arthur Sharif/Sotheby’s International Realty

Now looking to be closer to their adult daughter on the East Coast, they are putting the five-bedroom home on the market for $44 million—the most expensive listing in Palo Alto.

Waldfogel is an angel investor who co-founded Redback Networks, a telecommunications-equipment company. MacLean previously had a career in fundraising.

The kitchen and family room open to the garden and pool. Arthur Sharif/Sotheby’s International Realty

Cast alcoves and mahogany shelves house the couple’s books and ceramics. Arthur Sharif/Sotheby’s International Realty

The couple purchased the roughly 0.4-acre site for $7.1 million in 2000 and demolished a circa-1930s Spanish Colonial home. The house they built pinwheels around a central staircase. It has 7,900 square feet of livable space, with four distinct courtyards and a pool.

A key feature of the home is a cast-in-place concrete wall, or spine, that is two stories high and about 80 feet long. “There’s a little bit of controlled chaos in what comes out of the form,” unlike a perfectly uniform surface, Waldfogel said. “If you want that, you do it in plastic.”

Ehrlich said it took a few tries to get the concrete wall right. Arthur Sharif/Sotheby’s International Realty

‘It’s a really hard material to tame,’ Ehrlich said of concrete. Workers learned as they went, and Waldfogel and Helyn grew to appreciate the imperfect material. Arthur Sharif/Sotheby’s International Realty

A central staircase is housed in a glass tower. Arthur Sharif/Sotheby’s International Realty

Waldfogel said he and his wife are thinking about the next phase of life now that their daughter is grown, although they have not decided where they will move. They also have a home in Sun Valley, Idaho.

“Right now we’re just trying to emotionally let go and decide what to do next,” he said.

Arthur Sharif/Sotheby’s International Realty

Two wings of the house are connected by horizontal planes. Arthur Sharif/Sotheby’s International Realty

Palo Alto, an epicenter of venture capital and tech startups in Silicon Valley, is home to some of the country’s biggest tech titans. Sales volume and prices are rising, with a median sale price of $3.5 million for the three months ending in August, up 5.8% year-over-year, according to real-estate brokerage Redfin.

Arthur Sharif of Sotheby’s International Realty—San Francisco Brokerage has the listing.

Prestige Property: 3804/439 Collins Street, Melbourne VIC

Lofty living in the heart of Melbourne’s CBD.

A five-bedroom Palo Alto home designed by Steven Ehrlich is listed for $44 million, making it the city’s most expensive listing. Built around a dramatic concrete spine, the home features four courtyards and a pool.