Luigi Rosselli, Polished concrete structural slab

The Best of Concrete: Grey Matter

Luigi Rosselli Architects have applied a lot of thought to grey matter over the years: off-form concrete, cement toppings, polished concrete, precast, glass reinforced; concrete is a material of many forms. In-situ cast off-form concrete combines a structural solution with a lasting finish, textured or smooth, coloured dark or light. Using weathered timbers, corrugated iron and embossed patterns or shapes in the formwork provide highly textured and expressive finishes.

While the natural Portland Cement colour is preferred, off-white cements and concrete dyes can add drama. Black and white aggregates can be added to floor slabs, revealed when the floor is polished to a very resilient, hardwearing sheen. Waxing the surface softens the tactile quality.

Glass reinforced concrete (GRC) is increasingly being used to minimise the carbon footprint and energy impact by reducing the amount of material involved. One of the primary motivations for carefully using concrete is to provide a building with few maintenance requirements and a structure that is designed to spread its high production energy cost over centuries.

Luigi Rosselli, Concrete Cantilevers, Curved Offset Balconies, Exposed Off Form Concrete — Concrete as a strong structurally expressive material in this eastern beaches house, echoing the stone outcrops balancing over the ocean. © Luigi Rosselli Architects

Luigi Rosselli, Concrete Fireplace, Curved Fireplace, Built in Fireplace, Concrete Base — The structural of form concrete beams are expressed inside the house and warp to form a fireplace hearth in this home in the eastern suburbs of Sydney. Note the stereo speakers have been formed in concrete too! © Luigi Rosselli Architects

Concrete and Aluminium Louvres — Sandstone, anodised aluminium and off form concrete patterned with weathered timbers reflect the coarse geologocal textures and natural colours of the surrounding sandstone cliffs and cove. © Luigi Rosselli Architects

Luigi Rosselli, Waterfront View, Balcony, Framed View, Off-form concrete edge beams — Built to last, the house uses off-form concrete slabs and edge beams allowing the robust cantilever. A good engineer is critical (Rooney and Bye Consultant Engineers) © Luigi Rosselli Architects

Luigi Rosselli, Cantilever, Countryside House, Concrete country house soffit — The off-form concrete soffit of this country house in Armidale tapers from a concealed post to the window ledge. © Luigi Rosselli Architects

Luigi Rosselli, Floating House, Cantilever, Corrugated iron and off-form concrete — Corrugated iron and an off-form concrete base give this rural property a high degree of bushfire resistance. © Luigi Rosselli Architects

Luigi Rosselli, Sandstone, Smooth White Render, Concrete eaves in Sydney — The concrete eaves on this Sydney house reflect a warm light when up lit, tying together rough sandstone and smooth white render. © Luigi Rosselli Architects

Luigi Rosselli, Textured Formwork, Concrete, Timber Shutters, Corrugated iron concrete formwork — Corrugated iron was used as a formwork for this family home at North Bondi. The undulating off white cement concrete façade at the base of the building is aligned with the corrugated iron Colorbond steel garage door. © Luigi Rosselli Architects

Luigi Rosselli, Glass reinforced concrete (GRC) — Glass reinforced concrete (GRC) is used when the structural strength is not required. In this Woollahra house a durable finish was required. © Luigi Rosselli Architects

Luigi Rosselli, Textured glass reinforced concrete (GRC) — The GRC is textured with vertical timber boards in panels. GRC allows for much less concrete to be used, saving energy. © Luigi Rosselli Architects

Luigi Rosselli, Textured glass reinforced concrete (GRC) weathers gracefully — The textured GRC façade will weather gracefully over time. The manufacturer was Quatro Design in Brisbane. © Luigi Rosselli Architects

Luigi Rosselli, Curved glass reinforced concrete (GRC) fireplace — This curved GRC fireplace and TV unit in a beachside home ties in with a palette of polished concrete floors, in-situ cast off-form concrete and dark polished concrete benchtops. © Luigi Rosselli Architects

Luigi Rosselli, Glass reinforced concrete truss Sydney Resturant — This glass reinforced concrete truss in a Sydney restaurant forms an architectural perimeter around the elevated kitchen and bar areas. It is an exceptionally resilient finish that is also lightweight enough to easily install in a commercial fit out. © Luigi Rosselli Architects

Luigi Rosselli, Concrete truss is a reference to the concrete bridges of industrialised Milan — The concrete truss is a reference to the concrete bridges of industrialised Milan, a theme that’s carried through the restaurant with black steel and rugged, textural finishes. © Luigi Rosselli Architects

Luigi Rosselli, Timber Battens, Joinery, External Seating, Built in BBQ, Concrete durable benchtop — Concrete is a durable benchtop, as in this terrace BBQ. In this case with a steel trowel finish and an outdoor grade sealer. © Luigi Rosselli Architects

Luigi Rosselli, Built in BBQ, Concrete Bench, Off-form concrete BBQ — The best barbeque to integrate is the Electrolux. Most of the competition have been designed by butchers. © Luigi Rosselli Architects

Luigi Rosselli, Kitchen, Kitchen Design, Kitchen Island Bench, Solid polished concrete benchtop with black oxides — This solid concrete bench was formed and polished off site. It has black mineral oxides added to it to give it a deep grey black colour. © Luigi Rosselli Architects

Luigi Rosselli, Smooth polished concrete finish — The smooth polished finish used with this benchtop gives it a beautiful sheen. © Luigi Rosselli Architects

Luigi Rosselli, Waxed concrete finish on a stair — The waxed concrete finish on this stair, in a heritage listed house in Double Bay, gives it a timeless finish that ties in perfectly with cement topped wall designed by Professor Leslie Wilkinson. © Luigi Rosselli Architects

Luigi Rosselli, Concrete Handrail, Waxed Concrete Finish — The handrail in this stair is formed in concrete. The wax finish makes it smooth to the touch and brings out a lustrous patina. © Luigi Rosselli Architects

Polished concrete floor, Luigi Rosselli — This polished concrete floor in a prestigious Sydney residence not only forms a clean modern finish, it is very low maintenance. Under floor hydronic heating, powerered by a geothermal bore, provides a low energy source of heat. The topping slab poured over the underfloor heating can be fully customised to provide a range of finishes. © Luigi Rosselli Architects

Luigi Rosselli, Aged concrete — Concrete is at its best when it ages, it gains character and warmth. In the meantime lay rugs and leather over it. © Luigi Rosselli Architects