decus
Ultramarine Open-plan living space with a charcoal sectional sofa and leather lounge chair opening onto a terrace with a sculptural stone chair, framed by a sweeping coastal harbour view

Ultramarine

Ultramarine Kitchen with a curved grey marble island and matching splashback, a sculptural white pendant range hood, dark cooktop, wood bar stools, and floor-to-ceiling walnut cabinetry
Ultramarine Close-up of a rounded grey marble countertop edge meeting a curved wooden corner post, with small ceramic vases on top and a wooden stool beside it
Ultramarine Open-plan dining and kitchen space with a wooden dining table, mixed black and curved wood chairs, a marble kitchen island with sculptural white range hood, and coastal views through glass doors.
Ultramarine Ornate arched doorway with black-framed reeded glass doors opening onto a butler's pantry featuring curved wood cabinetry and dark upper cabinets with fluted glass fronts
Ultramarine Close-up of dark navy glass-front cabinets with slim brass handles, displaying rows of textured glassware including tumblers and stemmed wine glasses
Ultramarine Sculptural grey stone lounge chair with matching side tables on a terrace overlooking a coastal harbour with boats and green headlands beyond a black railing
Ultramarine Living room with a charcoal linen sofa, sculptural wood side table, and a tall totemic ceramic sculpture, opening through an archway to a staircase where a curly-coated dog sits
Ultramarine A minimalist alcove viewed through an arched doorway, featuring a cream boucle sofa with vertical channel-tufted cushions on a black plinth base. A small framed artwork with a muted teal-green panel hangs on the wall above, and a rounded, matte cream ceramic vase sits on the stone floor beside the sofa. Soft, even light fills the neutral, monochromatic space.
Ultramarine A pale, minimalist living space with a large abstract black-and-white maze-patterned artwork centered on the wall above a slim glass console table. Two black disc-shaped wall sconces flank the artwork. The console holds an abstract sculptural object, stacked books, and a small ceramic vessel. A pale blue bulbous ceramic vase and a grey rounded vase sit on the patterned stone floor, alongside a round white paper globe lamp on thin black legs. A beige boucle sofa is visible in the foreground, and an arched doorway opens to the left.
Ultramarine A close-up, top-down view of a beige boucle sofa's channel-tufted, petal-like cushion detail beside a round matte cream ceramic vase with a dark glazed opening. Both sit on a stone floor patterned with pale limestone tiles bordered by strips of grey-veined marble.
Ultramarine Sitting room with an arched period window featuring stained glass panels above a built-in terracotta banquette, a curved white bouclé armchair, an organic-shaped coffee table, and a decorative blue-and-white ceramic table lamp
Ultramarine Sitting room with an arched period window featuring stained glass panels above a built-in terracotta banquette, a curved white bouclé armchair, an organic-shaped coffee table, and a decorative blue-and-white ceramic table lamp
Ultramarine Curved plaster fireplace with a black inset grate holding logs, set on a dramatic veined marble hearth, with a matching marble bench visible in the background.
Ultramarine Narrow home office with a built-in wooden desk, cream rocking chair, sculptural arm-shaped wall lamp, and floor-to-ceiling wood cabinetry beside a glass door leading to a terrace with coastal views.
Ultramarine Close-up of oak panelled cabinetry doors with fine round push-latch details and slim vertical trim
Ultramarine Upholstered daybed with a bolster cushion positioned beside floor-to-ceiling glass overlooking an internal courtyard tree, with a woven side table and sculptural lamp nearby
Ultramarine Camel leather modular lounge chairs against fluted wood panelling, with a small red side table, floor-to-ceiling curtains, and a glass sculptural object on a round wood table in the foreground
Ultramarine Double vanity in dark veined marble with two suspended angled mirrors, integrated basins, and black tapware, framed by a large window with a decorative timber truss and coastal ocean view.
Contemporary master ensuite by Decus featuring textured white tiles, grey veined stone flooring, blue towels and a dark timber walk-in wardrobe with custom joinery.
Ultramarine Minimal bedroom corner with a curved, upholstered wooden headboard, a sleek angular reading light, and a small dark vase with a leafy branch, beside a black-framed reeded glass door.
Ultramarine Bedroom with a curved wood-framed grey upholstered headboard, textured charcoal throw, a sculptural wooden stool, and a wall-mounted disc sculpture, opening onto a hallway beyond.
Ultramarine A striking bathroom vanity carved from bold grey-and-white swirling marble with an integrated sink and brass gooseneck tap, set against a wall of vertical fluted timber slats. A cylindrical brass wall sconce is mounted to the right, above a glass vase of dried grasses and a green ceramic vessel on the counter. A narrow window with a woven roller blind sits centered between the timber panels, framing a view of greenery outside.
Ultramarine A close-up detail of a sculptural grey-and-white veined marble sink basin with a curved brushed-brass gooseneck tap and matching round single-lever mixer. The marble's dramatic swirling grain is echoed in a mirror reflection above, with a timber-panelled wall visible at the edge of the frame.

Set in Sydney’s captivating harbourside suburb of Mosman, Ultramarine crafts a gently layered family home - calm, approachable and soft to the touch. Moving from a contemporary glass and steel home on the slopes of Balmoral, the clients purchased an early 1900s Federation home in Mosman with a vision to create a lifestyle-driven oasis for their young family of five. The homeowners had worked with Decus previously, fostering a trusting and respectful relationship from the initial stages of the project. “Our response to the brief was unique as the clients gave us a lot of latitude on the conceptual direction,” reflects Alexandra Donohoe Church, Founder and Managing Director of Decus.

Luigi Rosselli Architects extended the footprint of the old home, overlaying their signature design aesthetic while drawing in abundant natural light. Building on this approach, Decus sought to marry the decorative qualities of the Federation home with the architecture’s contemporary materials. “We wanted the house to feel easy, smooth, delicate yet robust,” says Alexandra. A relaxed and effortless sensibility became the driving ambition of the design, with Decus focussing on the detail and tactility of interfaces between the house and occupants.

Moving through the home’s central corridor, a series of grand arched openings create porous boundaries between rooms and transition spaces. Beyond fluted glass doors, a formal sitting room honours the historic character of the old home. While the existing ceiling was in a state of disrepair, its ornate detailing is tenderly referenced in a new, organic ceiling detail – “a gestural swoop,” explains Alexandra, which grounds the arrangement of lounge settings below. A dramatic, full-height fireplace shroud and sculpted window seat sit in sculptural dialogue, their minimalist expression contrasted by decorative architraves and stained-glass windows.

An internal courtyard unites the home’s two primary levels, animating the calm, natural palette with soft washes of light and shade. Nestled on the lower ground floor, a guest room and rumpus space for the children opens out to a barbeque area, lawn and pool, offering an additional informal entertaining space for the family to delight in the Mosman’s natural surroundings. With thoughtful details and a soothing sensibility, Ultramarine fortifies Decus’ considered approach to residential design. The ambition to create a warm, comforting and enjoyable home has yielded a welcoming refuge for the young family. “Ultimately, the design cultivates connection for its inhabitants – a place to gather, relax and play,” smiles Alexandra.

Ultramarine is built on the land of the Borogegal and Cammeraigal People of the Eora Nation.

Photography Anson Smart
Styling Jack Milenkovic
Architect Luigi Rosselli
Build GNC Quality
Landscaping Spirit Level

Collaborators on this project include Atelier Furniture Simple Studio Granite Marble Works Euro Marble SNB Stone Stone Italiana Onsite Di Lorenzo Bisanna Tiles Jeff Martin Joinery Tongue & Groove Venetian Plaster Gallery Vitrocsa Viabizzuno Volker Haug Euroluce EST Lighting Milly Dent Candana Vola Brodware English Tapware ADH Studio dedece Dulux Armadillo The Rug Est COMA Gallery M Contemporary Utopia Art Sydney Chalk Horse Daniel Boddam StudioTwentySeven Gallery Sally Dan Cuthbert Fineworks Paddington Secondi Stylecraft Oliver Thom Wever & Ducré Anna Charlesworth Fred International The Finery Company Ralph Pucci Lia Klugman Love After Love Robert Plumb Design Nation Cassina Living Divani Space Furniture. Garnier et Linker Dimitri Vargas Luna Launay De Padova Allied Maker Ondene Studio In Bed Store Studio Henry Wilson District Porters Paint Poliform Cult Design KE-ZU Christopher Boots Milgate Studio Tops