Understanding the ‘house within a house’ model
Across South Australia, the way people think about housing is changing. Rising property prices, higher construction costs and changing family dynamics are all influencing the types of homes buyers now want - and one design trend quietly gaining momentum is the ‘house within a house’ model.
While the phrase may sound unusual, the concept itself is becoming increasingly common. At its core, it refers to a home designed with two semi-independent living zones under one roofline. Rather than building a granny flat or detached dwelling, some homeowners are opting to create flexible spaces that allow multiple generations or occupants to live together, while still maintaining a degree of privacy and independence.
For many South Australians, the appeal is practical. But before embracing the concept, it’s important to understand both the opportunities and the challenges involved.
What does a ‘house within a house’ actually mean?
Unlike a traditional family home with one shared layout, a ‘house within a house’ design creates separate zones within a single dwelling. This may include an additional living area, extra bathroom, private bedroom wing or even a secondary kitchenette and semi-independent entrance.
The goal isn’t necessarily to create two legally separate homes. Instead, it’s about creating a flexible property that can adapt to changing family needs over time.
For some households, this might mean accommodating ageing parents. For others, it could provide space for adult children, guests or a home office with greater privacy.
Why the model is becoming more popular
The growing interest in this type of housing reflects broader changes happening across the South Australian property market.
Affordability pressures are encouraging more families to live together for longer periods, while buyers are increasingly looking for homes that can adapt as their circumstances change.
A house-within-a-house design can offer flexibility without requiring families to move homes as life stages evolve. A private space used by teenage children today may later become accommodation for elderly parents or visiting family members.
Many buyers also see these layouts as a way to future-proof their property and make better use of available space.
Planning and compliance matter
While the concept sounds straightforward, this is often where homeowners can run into difficulties. Relatively small design changes - such as adding another kitchen or creating separate access - can affect how a property is classified under South Australia’s planning rules. Depending on the layout, the home may change its class as a single dwelling to dependent accommodation or dual occupancy arrangement.
These classifications can influence approval requirements, parking provisions, fire safety standards and utility considerations.
Homeowners who proceed without understanding these rules can unintentionally create compliance problems that become expensive to rectify later. For example, non-approved building work is likely to show up on the Form 1 (council search) when the property is offered for sale. This can be negative and could cause the sale of the home to fall through.
Good design is essential
A successful ‘house within a house’ layout involves much more than simply dividing up floor space. Privacy, sound insulation, ventilation and natural light all play an important role in whether the home functions comfortably for occupants. Shared walls, awkward access and poorly planned living areas can quickly create frustration if the design hasn’t been carefully considered.
Older homes can also present structural or plumbing limitations when owners attempt to retrofit them into dual-living arrangements. What appears simple at first may ultimately require significant upgrades to drainage, electrical systems or fire safety measures. For example, every room capable of being used as a bedroom must be protected by a hard-wired smoke alarm.
Thinking long term
Flexible housing layouts are attracting growing attention from buyers who value adaptability and multigenerational living options. However, homeowners should be cautious about assuming these spaces can automatically be rented separately or used for short-term accommodation without appropriate approvals.
Understanding both the construction and compliance side of these projects is essential before committing to renovations or purchasing a modified property.
Where expert advice can help
Because these projects sit at the intersection of planning, design and construction, independent advice can make a significant difference. Members of the Association of Building Consultants can assist homeowners and buyers by assessing existing structures, identifying compliance concerns and reviewing renovation feasibility before work begins.
The earlier potential issues are identified, the easier - and often cheaper - they are to address.
