When architect Ronald Tam saw a house that was up for sale about 10 years ago in Macau's green Coloane island, he immediately recognised its potential.

But it wasn't the building that excited him. The seafront plot on which it stood, he knew, could accommodate a far more striking - and spacious - home.

"It's a rule in Macau that when you build under the ground level, you can go as deep as you like," he says, "which really worked to our advantage."

With a Hong Kong-based client on board as the owner, Tam, of 9B Architecture, demolished the old, two-level structure and built in its place a five-storey, 728 square metre holiday home with ample entertaining space and a lift. Positioning the house on a slope meant the bottom floors were only partially underground, and all levels enjoyed a frontal sea view.

The subterranean aspect of the building offered another advantage - privacy. From the street, it appears to be a modest two-storey house; it is only upon entry that it unfurls into a vast expanse of light and glass, complete with a 16-metre outdoor pool tucked beneath it, extending onto a patch of green.

Tam fitted into the property eight bedrooms, most of which face the sea; five are en-suites. The master bedroom and a smaller room are on the top floor; the others are spread across lower ground floors two and three; just one room faces an inner courtyard.

There is also a series of multifunctional and communal spaces. The largest of these, "The Great Room", on the first lower ground floor, combines a lounge and dining area plus an open kitchen with a central island-cum-breakfast bar. From here, there is an unobstructed view of the rest of the floor and beyond, through glass terrace doors.

"Over the years, I've found that people don't stay and socialise in a space if there's not a kitchen or pantry - somewhere to get tea or coffee," Tam says. "People would often rather sit at a dining table to enjoy coffee - while they chat or work on their laptop - than go into a separate lounge, so this really is the main entertaining area."

Working with a local contractor, Cia De Ferragens Aluminio Ou Son (tel: 853 2840 1350), for the interior and exterior fit-out, Tam allowed the architecture to lead the aesthetic.

"I guess you could call it 'minimal', although I don't like the term," he says. "For me, this is mostly about expressing richness through the space and form of the interior, and small details of the fixtures. I concentrated on designing the details of a bookshelf, or the ceiling; none of these would ever be called decorative."

The understated interior features simple, whitewashed walls and ceilings, with light oak flooring throughout most of the house. Skirting boards are absent; air-conditioning vents are hidden and lighting is unobtrusive.

Architectural accents are provided by an exposed steel-and-glass staircase that runs through the property and glass sky-lights that flood the interior with natural light. Warmth is added through back-lit wood-hued shelves and cabinets, in addition to a fireplace in the television lounge on the entry-level ground floor.

Tam was keen to ensure that the communal spaces be versatile. Furniture is simple, light and easily moved around, particularly the sofas, which are modular. The relative simplicity of the aesthetic also allows the owner to introduce pieces of furniture from his other properties.

Yet it is the architectural design that has placed the wall-to-wall views centre stage, drawing the eye to a seascape that feels well removed from Macau's more dramatic urban neighbourhoods.

Television room A contemporary, timber gas fireplace is a feature in the ground-floor TV lounge. The joinery was custom built with engineered walnut timber panels (HK$3,000 per square metre from Joyful Sky, 3/F, CRE Building, 303 Hennessy Road, Wan Chai, tel: 2152 0701). The fireplace (60,000 yuan/HK$76,000) came from Canature (www.canature-fire.com), in Shanghai. The staircase, which runs through the property, combines painted mild steel, with glass and a white oak handrail to match the engineered white oak flooring (HK$1,200 per square metre, also from Joyful Sky). The sofa came from another of the owner’s homes. The B&B Italia side tables (from €285-€457/HK$2,500- HK$4,000) came from SAG’ 80 Furniture (www.sag80.com), in Milan.

Garden The Gloster Cloud sofa and coffee table (HK$99,850 in total) came from Everything Under the Sun (9/F, Horizon Plaza, 2 Lee Wing Street, Ap Lei Chau, tel: 2554 9088).

Pool The 16-metre, mosaic-tiled, infinity-edged swimming pool, framed with black granite, cost about HK$300,000 (including jet bath equipment, not shown). The Sani-Crete quartz stone (HK$750 per square metre) used for the paving came from Greatmat Technology (HK) (32/F, 148 Electric Road, North Point, tel: 2891 2111). Unable to use timber because of the high humidity above the pool, Tam clad the ceiling overhang in dark timber-patterned aluminium (sourced by the contractor).

Dining area Part of The Great Room, the dining area sits adjacent to an open kitchen and lounge space on the lower ground floor. The Robin table (€2,676), which seats 10; the Kristalia armchairs (€300 each) and the Foscarini O-Space suspended lamp (€585 each), all came from SAG’ 80 Furniture. The cutlery was from Muji (various locations; www.muji.com.hk).

Master bedroom On the top floor, the master bedroom sits under a pitched roof ceiling, and features a wood-effect laminate-clad walk-in wardrobe and en-suite bathroom. The Paola Lenti Atollo sofa (€5,900) came from Corso Europa Emporio Casa (www.corso-europa.com), in Milan; the side table, bedside lamp and bed were bought years ago. Tam has installed a ceiling trough to the side of the room for indirect lighting. On the wall behind the bed, the two Pallucco Fold Applique lights (€250 each) came from SAG’ 80 Furniture.

Kitchen The Kristalia BCN Hocker Wood stools (€250 each) came from SAG’ 80 Furniture. The kitchen cabinets, fronted with Formica laminate, were custom designed for about HK$100,000 by Midfield (27/F, Paul Y Centre, 51 Hung To Road, Kwun Tong, tel: 3148 9122), which was also the source for the Formica Stone countertops. The refrigerator is from Fisher & Paykel (fisherpaykel.com) and the wine fridge from Gilman Home Appliances (www.gilman-group.com).

Guest bedroom and bathroom Ronald Tam of 9B Architecture (4/F, 155 Wong Nai Chung Road, Happy Valley, tel: 2537 0008) was inspired by contemporary hotel design in the layout of this smaller guest bedroom on one of the lower floors. Moca Creme limestone was used to clad the floor, walls and bath. The bedroom furniture was acquired years ago.

Twin bedroom This bedroom on the lowest floor opens out onto a rear courtyard. Woodpatterned Formica sliding doors screen the toilet. The bedroom furniture was acquired years ago. The Fado table lamps (HK$179.90 each) came from Ikea (various locations; www.ikea.com.hk).

 

Dry clean Although the kitchen has a dishwasher, architect Ronald Tam wanted to provide an area to dry hand-washed dishes, too. With the luxury of a deep countertop, he was able to install a drip tray directly behind the sink with a connected drain. He designed this to fit a simple, inexpensive dish rack (about HK$85) from Muji.

"The idea was to make sure that the rack doesn't take up space to the side of the sink," he says. "With this being an open kitchen, a random dish rack on the countertop would just look ugly."