The Symphony is a knockdown-rebuild in Sydney: one home designed by OIC Architects for several generations of a family. We designed the architecture and the interiors: 480 m² of internal space on a 963 m² block, with six bedrooms, eight bathrooms, a gym, a temperature-controlled pool and parking for six. It was completed in 2023.

Key facts

Type: Knockdown-rebuild, one home for several generations
Location: Sydney
Approval route: DA
Services: Architecture, interiors
Status: Completed (2023)
Block: 963 m²

Internal area: 480 m²
Bedrooms: 6
Bathrooms: 8
Parking: 6 cars
Living areas: 3

Special features: Home gym; Temperature-controlled pool; Mancave; Skylights

The brief

The owner came to us unsure where to start, with a scattered picture of what they wanted. The goal was clear, though: one house for the whole family across several generations, to keep and hand down. The site had been bought as a knockdown-rebuild.

We started with how the family would use the house, now and later, including whether there might be more children, and planned for it either way. Cheryl, the owner, talks about this in her video interview.

What made it hard

The wish list was long for one house. Six bedrooms, eight bathrooms, three living areas, a gym, a pool and a mancave had to fit into a single form that still felt like a home. With 480 m² inside, the middle of the plan could easily have ended up dark.

What we decided, and why

We let the architectural form run from the outside in. The curved roof, timber battens and split stone of the street front carry through to a dark split-stone wall inside, where a cantilevered timber stair rises beside a sunken living room.

Skylights bring daylight deep into the plan. Windows frame particular views: the gym opens to the garden, and a well-positioned window frames the city beyond. At the back, a covered deck opens onto the terrace, and broad steps drop into the pool.

The result

The Symphony was completed in 2023. For the family, the measure that matters is a house planned around how they live, and built to last for the generations after them.

The finished project

The Symphony in pictures

From the street to the pool and the sunken living room: the finished home, designed for several generations of one family.

12 pictures · completed · select any picture to see it full screen

The Symphony's street front: vertical timber battens over split stone, under a curved white roof edge, Sydney — 01The street front: timber battens over split stone, under the curved roof.

A covered timber deck under hanging greenery, opening onto the terrace and garden, The Symphony, Sydney — 02The covered timber deck, opening onto the terrace and garden.

The terrace at sunset, with broad stone steps down into the pool and outdoor seating under the pergola, The Symphony, Sydney — 03The terrace at sunset, where broad steps drop into the pool.

The rear of The Symphony at night: lit rooms behind full-height glazing, arched windows and loungers on the terrace, Sydney — 04The rear of the house at night, its arched windows glowing over the terrace.

The Symphony from the garden at night, with the pool and the rooms inside lit, Sydney — 05The house at night from the garden, with the pool and the rooms inside lit.

Sunken living room with large sculptural pendants and a floating stair against a dark textured stone wall, The Symphony, Sydney — 06The sunken living room under sculptural pendants, with the floating stair against a dark stone wall.

The sunken living room from the side, with a sculptural pendant and floor lamp, and the stone wall and stair beyond, The Symphony, Sydney — 07The sunken living room from the side, a sculptural pendant above and the stair beyond.

Floating stair with pale timber treads cantilevered from a dark split-stone wall, with planters below, The Symphony, Sydney — 08The floating stair, its pale timber treads cantilevered from a dark split-stone wall.

Kitchen with a fluted timber island, a curved pendant light and a long window onto the trees, The Symphony, Sydney — 09The kitchen: a fluted island under sculptural pendants, with a long window to the trees.

Dining area with an oval table and upholstered chairs beside the timber kitchen joinery, The Symphony, Sydney — 10The dining area: an oval table and upholstered chairs beside the kitchen joinery.

Home gym with racked dumbbells and kettlebells against a dark ribbed wall, opening to the garden, The Symphony, Sydney — 11The home gym, weights racked against a dark ribbed wall and opening to the garden.

Bedroom with timber wall panelling, a low bed and a slim pendant beside it, The Symphony, Sydney — 12A bedroom in warm timber, with a slim pendant beside the bed.

The street · 01 / 12

What a multi-generational knockdown-rebuild involves

Start with the approval route, because it shapes the design. In NSW, a new one- or two-storey house can often be approved as complying development (a CDC) under the state's Housing Code. The lot generally has to be in a residential zone, at least 200 m² and 6 m wide, and it can't be a heritage item or sit in a heritage conservation area. Otherwise, it's a development application (DA) to council.

Every new home in NSW needs a BASIX certificate, which sets targets for water, energy and thermal performance. A pool has to be registered on the NSW Swimming Pool Register and kept behind a compliant child-resistant barrier.

Designing for several generations is mostly about flexibility. What we usually work through early:

a bedroom and full bathroom on the ground floor
step-free paths from the car and the street to the main living level
living areas far enough apart that two parts of the family can use them at once
room for a lift later, even if you don't install one now
a self-contained flat, if you want one: in planning terms that's a secondary dwelling (a granny flat), with its own rules

Houses built before the late 1980s may contain asbestos, so have the old house checked before demolition. More than 10 m² of non-friable asbestos has to be removed by a licensed removalist.

"OIC considered what I'm going to do and how my family's going to use the space, not just the house itself. They asked things I hadn't even thought about, like whether I'd have more kids, and they planned for it either way."

Cheryl, The Symphony

Watch the full interview

Questions about projects like this

Can a knockdown-rebuild be approved with a CDC?

Often, yes. A new one- or two-storey house can be approved as complying development under the state's Housing Code if the lot qualifies and the design meets the code's standards for things like height, setbacks and privacy. It generally can't be used for a heritage item or in a heritage conservation area, and some bushfire and flood affectations rule it out. If the CDC route is closed, you lodge a DA with council. Check your Section 10.7 planning certificate first; our CDC or DA guide explains what to look for.

Can we add a granny flat for a parent?

Usually, if the lot allows it. A secondary dwelling (a granny flat) is a self-contained home on the same lot as the main house: inside it, attached to it or separate. To approve one as complying development, the lot generally needs to be at least 450 m², unless the flat sits entirely within the existing house; otherwise it goes through a DA. A lot with a secondary dwelling can't be subdivided, so the flat can't be sold separately later.

Start a project like this

ServiceNew homes & knockdown-rebuildsArchitects for knockdown-rebuilds and new family homes in Sydney. Renovate-or-rebuild advice, design, DA or CDC approvals and construction documentation.Paid first stepFeasibility studyBefore you buy, renovate or rebuild: a property feasibility study covering planning potential, CDC or DA, budget and design options.

Guides for this kind of project

Guide · HomesKnock down and rebuild, or renovate? How to decide Knock down and rebuild, or renovate your Sydney home? Compare structure, heritage, today's planning rules, approvals, cost, tax and where you'll live.11 min read Guide · HomesRenovation over budget? How to avoid paying for a design you can't afford to build Why renovations go over budget before a brick is laid, what Sydney building costs per m², and a budget-first design process with cost checks at each stage.10 min read

All guides

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Tell us what you are planning. In a free 15-minute call we will tell you honestly whether we are the right fit, what the approval route looks like and what the sensible next step is.

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An OIC architect going over plans with three builders on a construction site

The SymphonyMulti-generational home design · knockdown-rebuild · Sydney