Future-Proofing Luxury Homes: Design for Ageing-in-Place and Multi-Generational Living

By Franz Phan, Senior Building Designer, giantA Pty Ltd — 15+ years designing custom homes across Sydney's premium suburbs

Australians are living longer, staying in their homes well into their eighties and nineties, and increasingly sharing those homes with adult children, ageing parents, and grandchildren. The latest Census data from the Australian Bureau of Statistics shows multi-generational households rose by 21.8 per cent between 2016 and 2021, and that trajectory has only steepened since. For homeowners in Sydney's prestige belt — Vaucluse, Mosman, Bellevue Hill, Hunters Hill — the question is no longer whether to future-proof, but how to do it without compromising the architectural integrity and luxury appeal that drew them to the property in the first place.

At giantA, we design homes meant to last decades, not just one renovation cycle. Future-proofing means embedding flexibility into the bones of the building: step-free circulation that feels generous rather than clinical, self-contained suites that read as guest wings rather than granny flats, and structural provisions that allow a bathroom to be retrofitted for accessibility in a single week rather than a three-month renovation. This guide sets out the design principles, regulatory context, and cost implications that Sydney luxury homeowners need to understand before committing to a future-proofing project.

What Does Future-Proofing a Luxury Home Actually Mean?

Future-proofing is the deliberate design of a home so that it remains functional, comfortable, and valuable across multiple life stages and household compositions. It is not the same as accessible design, which focuses specifically on disability compliance, nor is it identical to universal design, which aims for usability by people of all ages and abilities as a broad philosophy. Future-proofing sits at the intersection of these two approaches and adds a third dimension: adaptability. A future-proofed home can be reconfigured as household needs change without requiring major structural intervention.

In practice, this means three things. First, the home must support ageing-in-place — the ability of older residents to remain in the dwelling safely and independently as mobility, vision, and cognition decline. Second, it must accommodate multi-generational living — multiple adult generations sharing the dwelling simultaneously, each with a need for privacy and autonomy. Third, it must be adaptable — designed so that spaces can be repurposed (a study becomes a bedroom, a guest wing becomes a carer's quarters, a living room gains a lift) without demolishing walls or rewiring the entire electrical system.

The financial case is straightforward. The ABS reports that 95.9 per cent of older Australians live in private dwellings rather than cared accommodation, and 82.5 per cent of households with a reference person aged 65 or over had not moved in the previous five years. People stay in their homes, and a home designed to support that longevity retains its value and appeals to a broader buyer pool.

The Regulatory Landscape: Livable Housing Design Standards in NSW

The National Construction Code introduced mandatory Livable Housing Design provisions in NCC 2022, based on the Silver level of the Livable Housing Design Guidelines. These provisions require step-free access to an entry-level bathroom, wider internal doorways, reinforced bathroom walls for future grab-rail installation, and a toilet on the entry level. However, each state determines whether and when to adopt these provisions, and NSW has taken a notably cautious approach.

As of August 2026, NSW has not generally adopted the NCC Livable Housing Design provisions for Class 1a dwellings. The NSW Building Commissioner hosted a Liveable Housing Stakeholder Roundtable in February 2025, and the Building Commission NSW published a Discussion Paper titled "Liveable Housing Requirements in NSW," but no binding adoption date has been set. NCC 2022 Amendment 2 remains the code in force across NSW, with NCC 2025 adoption deferred until May 2027.

This creates an interesting paradox for luxury home design in Sydney. The Silver level is mandatory in most other states and is considered the baseline for new Class 1a construction nationally, yet in NSW it remains voluntary. For our clients, we treat the Silver level as a minimum design standard regardless of the regulatory gap, because the cost of incorporating step-free entries, wider doorways, and reinforced walls during construction is negligible compared to retrofitting them later. Clients who plan to sell interstate or to buyers from Victoria or Tasmania — where Silver is mandatory — also benefit from a home that meets or exceeds those standards.

Livable Housing Design Performance Levels Compared

Source: Livable Housing Design Guidelines, Australian Building Codes Board; NSW adoption status per Building Commission NSW Discussion Paper, February 2025.

Designing for Ageing-in-Place: Beyond Grab Rails and Ramps

The most common mistake in ageing-in-place design is treating it as a checklist of accessibility fixtures — grab rails, ramps, shower seats — bolted onto an otherwise conventional plan. This approach produces homes that look institutional and feel like compromises, which is precisely why many luxury homeowners resist the conversation entirely. The alternative, and the approach we take at giantA, is to design the structural and spatial provisions so that accessibility features can be added later invisibly, without any visible change to the home's character.

Reinforcing bathroom walls during construction costs approximately $200 to $500 per wall in additional noggings and plywood backing. The same operation after tiling and fit-out costs $3,000 to $8,000 per wall because it requires removing tiles, re-waterproofing, and retiling. Specifying 870mm doorways instead of 770mm doorways adds less than $100 per door in framing and architrave adjustments, but creates clearance for a standard wheelchair (which requires 800mm minimum clear opening). These are not luxury upgrades. They are marginal cost adjustments during construction that preserve the option to add accessibility features decades later without major disruption.

For Sydney's premium homes, the ageing-in-place conversation often centres on vertical movement. A three-storey home in Vaucluse or Mosman with the primary bedroom on the upper level becomes a liability when the owner can no longer manage stairs. We address this in two ways: first, by designing a ground-floor primary suite that can serve as the main bedroom when stairs become impractical (currently used as a guest room or study); and second, by including a lift shaft in the structural design, even if the lift itself is installed years later. A structural lift shaft costs $15,000 to $25,000 in additional framing and fire-rating during construction. Installing a lift later into a pre-designed shaft costs $45,000 to $80,000. Retrofitting a lift into a home not designed for one costs $120,000 to $200,000, including structural modifications, fire-rating upgrades, and compliance certification.

Ageing-in-Place Design Features: Cost of Provision vs Retrofit

Costs are indicative ranges for Sydney premium-suburb construction as at August 2026, based on giantA project data and HIA construction cost guides.

Multi-Generational Living: Designing for Privacy and Independence

The rise in multi-generational living is driven by several converging forces: housing affordability pressures keeping adult children at home longer, the cultural preferences of Sydney's diverse migrant communities, the cost of aged care (which averages $5,000 to $7,000 per month for assisted living), and the genuine preference of many families to remain connected across generations. The ABS Census 2026 includes a dedicated variable for multigenerational household composition (MHCD), reflecting the statistical significance of this trend.

For luxury homes, multi-generational design is less about squeezing in extra bedrooms and more about creating zones of autonomy within a single dwelling. The most successful projects we have delivered share three characteristics: a self-contained suite with its own bathroom, kitchenette, and entry; acoustic separation between zones (achieved through staggered stud walls, solid-core doors, and resilient channel ceiling systems); and visual privacy through strategic placement of windows and screening rather than relying on internal corridors alone.

In a recent project in Sydney's inner west, we designed a two-storey home where the ground floor functioned as a self-contained parents' retreat — with bedroom, bathroom, sitting room, and kitchenette — while the upper level housed the primary family. The two zones connected via an internal staircase with a solid-core door at the top, providing acoustic separation. The parents' retreat had its own external entry through a landscaped courtyard, meaning elderly parents could come and go independently without passing through the main living areas. This arrangement preserved family connection while respecting the autonomy that multi-generational living demands.

Multi-Generational Layout Options Compared

Cost premiums are relative to a standard luxury build without multi-generational provisions. Source: giantA project data, 2024–2026.

The Support at Home Programme: What It Means for Home Design

The Australian Government launched the Support at Home programme on 1 November 2025, a $4.3 billion reform consolidating previous Home Care Packages and Short-Term Restorative Care programmes. The programme includes an Assistive Technology and Home Modifications scheme that provides separate funding for approved modifications — grab rails, ramp installations, bathroom modifications, and doorway widening — for eligible older Australians. This changes the calculus for future-proofing because it means that even if homeowners do not pre-install accessibility features, there is now a structured funding pathway for retrofitting them later.

However, the programme covers modifications, not structural upgrades. It funds a grab rail installation ($200–$500) but not a structural lift shaft ($45,000–$80,000). It funds a doorway widening ($1,500–$3,000) but not moving load-bearing walls. This is why structural provision during construction remains the most cost-effective strategy: it reduces later modifications to items the programme will fund.

BASIX and Future-Proofing: The Energy Efficiency Overlap

Future-proofing and energy efficiency are not separate conversations. A home designed for ageing-in-place must also be thermally comfortable without imposing high energy costs on residents who may be on fixed incomes. BASIX, NSW's Building Sustainability Index, already requires 7-star NatHERS thermal performance and includes the new Passive House Standard method as an alternative compliance pathway from May 2026. A high-performing thermal envelope — good insulation, well-sealed construction, appropriate glazing — reduces heating and cooling costs by an average of $1,070 per year, according to NSW Planning Portal data.

For multi-generational homes, the energy calculus shifts. More occupants mean more internal heat gains (body heat, cooking, electronics), which can reduce heating demand in winter but increase cooling demand in summer. Zoned heating and cooling — separate climate control for different wings — becomes essential, both for comfort and for energy management. We design multi-zone HVAC systems with individual controls per zone, typically adding $8,000 to $15,000 to the mechanical fit-out cost, but reducing energy bills by 20 to 30 per cent compared to a single-zone system serving the same floor area.

Read our complete luxury home design features guide and our Sustainable Luxury BASIX and Passive House guide for more on energy-efficient design in premium homes.

How Much Does Future-Proofing Add to a Luxury Build?

The question every client asks is: what does this cost? The honest answer is that it depends on when you do it. Embedding future-proofing provisions during initial construction adds between 3 and 8 per cent to the total build cost of a luxury home, depending on the level of provision (Silver baseline versus Gold or Platinum). Retrofitting the same features later — often requiring demolition, re-waterproofing, and recertification — costs between 15 and 35 per cent of the original build cost, and takes weeks of disruptive construction while the home is occupied.

For a $2.5 million build in a premium Sydney suburb, the 3 to 8 per cent premium represents $75,000 to $200,000 — less than the cost of six months in an aged-care facility, and less than a single major retrofit renovation. The economics are compelling, and the design outcome is a home that feels generous and considered rather than adapted and institutional.

What Should Sydney Luxury Homeowners Do Next?

If you are planning a new build or major renovation in Sydney's premium suburbs, ask your building designer three questions before signing off on the plans. First: does the design include step-free access to at least one entry and one bathroom on the ground floor? Second: are bathroom walls structurally reinforced to accept grab rails without demolition? Third: is there a ground-floor room that could serve as a primary bedroom, and is there a structural provision for a lift if the home is multi-storey? If the answer to all three is yes, your home is future-proofed to a Silver-plus standard. If any answer is no, those are the conversations to have now, while the design is still on paper and the cost of change is measured in hundreds rather than thousands of dollars.

At giantA, we have been designing future-proofed luxury homes across Sydney for over 15 years. Our approach integrates accessibility, multi-generational living, and energy efficiency into the architectural concept from the first sketch, not as an afterthought. If you are planning a project in Vaucluse, Mosman, Bellevue Hill, Hunters Hill, or anywhere across Sydney's premium belt, contact us for a design consultation.

Frequently Asked Questions

What is ageing-in-place design and why does it matter for luxury homes?

Ageing-in-place design means building a home that supports safe, independent living as residents age, without requiring institutional care or major renovations. For luxury homes, it matters because 95.9 per cent of older Australians live in private dwellings and 82.5 per cent have not moved in five years (ABS). A home designed for ageing-in-place retains resale value and avoids the cost and disruption of retrofitting accessibility features later.

Is the NCC Livable Housing Design Standard mandatory in NSW?

No. As of August 2026, NSW has not generally adopted the NCC Livable Housing Design provisions (Part H8) for Class 1a dwellings. The NSW Building Commission published a Discussion Paper in February 2025 and held a stakeholder roundtable, but no adoption date has been set. NCC 2022 Amendment 2 remains the code in force, with NCC 2025 deferred until May 2027. Silver level remains voluntary in NSW but is mandatory in most other states.

How much does it cost to future-proof a luxury home during construction?

Embedding future-proofing provisions during construction adds approximately 3 to 8 per cent to the total build cost. For a $2.5 million luxury build, that is $75,000 to $200,000. This includes wider doorways, reinforced bathroom walls, step-free entries, a ground-floor primary suite provision, and a structural lift shaft. Retrofitting the same features later costs 15 to 35 per cent of the original build cost.

What is the Support at Home programme and how does it help with home modifications?

Support at Home is a $4.3 billion Australian Government aged-care reform launched on 1 November 2025. It consolidates previous Home Care Packages and includes an Assistive Technology and Home Modifications scheme that funds approved modifications such as grab rails, ramps, and bathroom adaptations. It covers modifications but not structural upgrades, so pre-provisioning structural features during construction remains essential.

How do you design a luxury home for multi-generational living?

The key is creating zones of autonomy within the dwelling: a self-contained suite with its own bathroom, kitchenette, and external entry, separated acoustically from the main family areas. Cost premium is typically 15 to 20 per cent of the build cost for a fully self-contained suite. Successful designs balance family connection with privacy through strategic window placement, solid-core doors, and separate entry paths.

Does BASIX interact with future-proofing design?

Yes. BASIX requires 7-star NatHERS thermal performance and offers a Passive House Standard compliance pathway from May 2026. A well-sealed, well-insulated thermal envelope reduces energy bills by approximately $1,070 per year (NSW Planning Portal), which is critical for residents on fixed incomes. Multi-generational homes benefit from zoned HVAC with individual controls per zone, adding $8,000 to $15,000 but reducing energy costs by 20 to 30 per cent.

What is the difference between Silver, Gold, and Platinum livable housing levels?

Silver (7 elements) is the minimum baseline: step-free entry, wider doorways, reinforced bathroom walls, and an entry-level toilet. Gold (12 elements) adds larger circulation spaces, sliding doors, and kitchen adaptability. Platinum (15 elements) includes fully accessible wet areas, adjustable benchtops, and living room accessibility features. Silver is mandatory under NCC 2022 in most Australian states but remains voluntary in NSW as of August 2026.

Should I include a lift in my luxury home design even if I don't need one now?

Yes, if the home is multi-storey. A structural lift shaft provision during construction costs $15,000 to $25,000. Installing a lift into that pre-designed shaft later costs $45,000 to $80,000. Retrofitting a lift into a home with no structural provision costs $120,000 to $200,000, including structural modifications and fire-rating compliance. The shaft can be used as storage or a wardrobe until the lift is needed.

About the author: Franz Phan is Senior Building Designer and Director of giantA Pty Ltd, with over 15 years of experience designing luxury custom homes across Sydney's premium suburbs. He is a licensed building designer and registered design practitioner with expertise in BASIX compliance, multi-generational home design, and accessible housing standards.

Contact giantA: Visit gianta.com.au or call our Sydney office to discuss your future-proofing luxury home project.