A secondary dwelling—commonly called a granny flat—is a self-contained dwelling established in conjunction with a principal dwelling on the same lot. It may be within, attached to or separate from the principal dwelling. Its legal classification depends on the approved use and documents, not a builder’s marketing description or the construction method.
This guide combines limited Conjola statistical context with statewide planning and building guidance. It does not establish the controls applying to a particular address. Before relying on any pathway, identify the legal lot, confirm the administering council and examine the current planning instruments, property mapping, title, services and approval history.
The locality record is based on the Australian Bureau of Statistics Suburbs and Localities geography, abbreviated as SAL. SAL boundaries are statistical approximations and are not cadastral, council or planning boundaries. They must not be treated as parcel boundaries or confused with SA1 geography. The supplied overlap with the ABS statistical LGA named Shoalhaven is useful routing context only; it does not itself prove that the formal council organisation responsible for a legal parcel is Shoalhaven City Council.
AMESCorp commercial disclosure and privacy warning: AMESCorp is the promoted commercial service provider and may benefit commercially from enquiries or purchases. Independently verify its scope, statements, pricing and any third-party recommendations. Do not send AMESCorp personal information, title records, plans, financial details or other property data through an unsecured channel. No guarantees are provided. Approval, cost, timing, rent, yield, value, finance, tax and investment outcomes depend on property-specific and personal circumstances.
Local granny-flat overview
The canonical locality record identifies Conjola as SAL code 11011, covering approximately 42.5857 square kilometres and eight mesh blocks. The same statistical record places the locality’s mapped area wholly within the ABS Shoalhaven LGA. These are verified geographic facts, but none identifies a parcel’s zone, legal constraints, development rights or approval authority.
The 2021 Census Conjola QuickStats reported 148 people, a median age of 52, 45 families and 62 private dwellings. These figures are historical context from the 2021 Census edition, not a description of present population, housing conditions or development demand. The small counts also make broad demographic, rental-market or investment conclusions unsafe. Current feasibility should therefore be based on property evidence rather than locality averages.
Under the NSW Government’s secondary-dwelling guidance, a secondary dwelling must be established with a principal dwelling and remain on the same lot. This planning pathway does not create an independently subdividable or separately saleable residence. A freestanding building is not automatically a lawful secondary dwelling, and an existing garage, shed or studio should not be treated as approved accommodation without checking its consent and occupation records.
State guidance says secondary dwellings are permitted in residential zones R1, R2, R3, R4 and R5. Other zones may permit them through the relevant local environmental plan. Permissibility is only an initial planning question: the proposed use, existing dwelling, site standards, mapped exclusions, access, services and title conditions must still be examined.
Start with an address or lot-and-deposited-plan search using the NSW property planning search and NSW Planning Portal Spatial Viewer. If official parcel records confirm administration by Shoalhaven City Council, use the council’s Local Environmental Plan information and online mapping tools to identify current instruments and maps. Their applicability must still be verified for the legal parcel and proposed pathway.
Address-level investigation should cover the title and deposited plan, easements, covenants, restrictions, lawful access, survey information, drainage and sewer assets, utility locations and the approval history of existing structures. Planning approval does not necessarily override private title restrictions. Relevant mapped or property-specific constraints should be recorded only after an official search confirms them; locality-wide assumptions about hazards, servicing or development capacity are not reliable.
Council rules and approval pathway
A secondary dwelling may be assessed through a development application or, when every relevant statutory requirement is met, as complying development. A development application is assessed by the responsible council. NSW guidance states that applications are lodged online through the NSW Planning Portal development-application process. The applicable environmental planning instruments, council requirements and proposal details determine the assessment material needed.
Complying development is a standards-based pathway. A council or appropriately registered certifier may issue a complying development certificate, but a certifier cannot waive statutory standards, exclusions or prerequisites. The NSW complying-development guidance explains this role and the need to comply with certificate conditions.
For the Housing SEPP complying-development pathway, NSW guidance identifies a minimum lot area of 450 square metres, except where the secondary dwelling is located wholly within an existing dwelling house. This is one eligibility requirement only. It is not a universal minimum for a council-assessed application and does not, by itself, establish complying-development eligibility.
Test the proposal against the current Schedule 1 of the State Environmental Planning Policy (Housing) 2021, the relevant provisions of the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008, mapped exclusions and any applicable local instrument. Current in-force provisions should be used rather than superseded Affordable Rental Housing SEPP material or generic online checklists.
Where a parcel is confirmed to be under Shoalhaven City Council, verify the applicable local environmental plan, development control plan and current council requirements for applications, contributions, waste, stormwater, driveways or vehicle crossings. Also check authority requirements for water, wastewater and other services. Rural or non-residential land requires particular care because local environmental plan provisions may differ from residential-zone rules.
The Housing SEPP does not itself require additional parking for a secondary dwelling. Existing consent conditions, the loss of existing parking, access safety, manoeuvring and other applicable controls can nevertheless affect the design and assessment.
Before choosing a pathway, confirm whether the work is internal, attached, detached or a conversion, and whether the principal dwelling and any structure being converted were lawfully approved for their present use. Review title restrictions and official mapping for constraints relevant to the address. Ask the council or certifier to identify required reports rather than ordering a generic set of studies.
Following approval, the work may require construction certification, a principal certifier, inspections and evidence that approval conditions have been met. Service NSW explains that an occupation certificate is required before occupying or using a new building, or using an existing building after an approved change of use. A concept plan, quotation, BASIX certificate or builder statement is not an approval or occupation certificate.
Costs and budgeting
A useful budget begins with the verified site and a documented scope. An advertised package amount cannot reliably account for planning investigations, access, ground conditions, services, approval requirements, conversion work or finishes. Separate confirmed quotations from allowances and unresolved site risks.
Include budget lines for:
- title, survey, planning and service investigations;
- design, engineering and specialist reports;
- application, Planning Portal and certifier charges;
- council contributions and authority fees where applicable;
- demolition, excavation, retaining and site preparation;
- construction, fixtures, finishes and BASIX commitments;
- sewer, drainage, water, electricity and communications work;
- driveways, paths, fencing, landscaping and waste removal;
- inspections, certificates, insurance and handover documentation; and
- finance charges and a contingency set for the investigated project.
Resolve service and access questions early. Connection locations, infrastructure capacity, lawful stormwater discharge, machinery access and authority approvals can affect both design and price. For a proposed conversion, investigate the structure’s approval status and condition, including structural work, fire safety, waterproofing, insulation, ventilation and services.
Give tenderers the same drawings, specifications, reports and site information. Require itemised quotes that identify exclusions, provisional sums, ground-condition assumptions, utility allowances, approval responsibilities, external works and nominated products. Verify current council and authority charges directly rather than relying on an old quotation or another property’s fees.
Building Commission NSW contract guidance requires a written contract for residential building work costing more than $5,000. More extensive large-job contract requirements apply above $20,000, and the maximum deposit is 10%. Read the Consumer Building Guide, ensure progress payments correspond with completed work and obtain advice about unclear terms before signing.
Home building compensation cover applies where required for residential building work valued at $20,000 or more including GST. Use the official HBC Check to verify the certificate before paying money or allowing work to begin. The builder’s legal entity, insured work and property details should match the contract and certificate.
Design and site considerations
Begin design with an accurate survey and a clear description of the proposal. Record boundaries, levels, existing structures, access, relevant trees, easements and available service information. Decide whether the secondary dwelling will be internal, attached or detached because that affects its documentation, construction interfaces, services and BASIX classification.
Test the layout against the relationship between both dwellings. Consider private open space, daylight, natural ventilation, visual and acoustic privacy, overlooking, safe pedestrian access, waste storage, clothes drying, deliveries and maintenance access. Review any effect on existing parking and vehicle movement. These practical matters can expose conflicts before detailed design begins.
Setbacks, height, floor area, landscaped area, site coverage and earthworks must be checked against the exact approval pathway and current controls. Do not copy design standards from another council, a different development type or an earlier planning instrument. Ask the responsible council or certifier to confirm which standards and documents apply to the parcel and proposal.
Investigate stormwater, wastewater and utilities before fixing the building footprint. Confirm lawful discharge, sewer or on-site wastewater requirements, service capacity and necessary authority approvals. Compare proposed excavation and connections with the title, deposited plan, survey and asset locations so that easements, private rights and infrastructure are not overlooked.
Use official mapping to identify constraints relevant to the address. Where a verified constraint applies, engage the appropriate specialist early enough to influence siting and construction. A generic inventory of possible hazards is less useful than a documented property search and a targeted response.
BASIX addresses water, energy use and thermal performance for applicable residential development. The Planning Portal provides specific BASIX secondary-dwelling project guidance for conversions, new secondary dwellings and projects involving new principal and secondary dwellings together. Integrate the applicable commitments into orientation, glazing, shading, insulation, ventilation, fixtures and services. Ensure approved commitments appear consistently in the drawings, specification, contract and completed work.
Prefabricated, modular or relocatable construction does not avoid planning, building, certification or occupation requirements. Similarly, physical room for a kitchen or bathroom does not establish that an outbuilding can lawfully be converted. Obtain approval records and professional assessment before incorporating an existing structure into the design.
Rental and investment considerations
Rental assessment should begin only after confirming the premises can lawfully be built and occupied. Check that the completed work matches its approval, retain required inspection records and obtain the occupation certificate before occupation or use. Confirm the approved classification rather than relying on advertising language.
A secondary dwelling remains on the same lot as the principal dwelling. Owners considering rental use should account for that shared title and site relationship when discussing lending, insurance, valuation, management and future sale with qualified advisers.
If the approved premises will be rented under a residential tenancy, follow current NSW Fair Trading guidance on residential tenancy agreements and the Residential Tenancies Act 2010. Use the current agreement and processes, and verify requirements concerning bonds, disclosures, condition reports, repairs, safety obligations and notices.
Do not assume that family occupation, a licence, boarder arrangements, short-term accommodation and a standard residential tenancy have identical legal treatment. Confirm the intended arrangement with current planning, tenancy and legal guidance.
For shared-site practicality, document access, privacy, waste storage, deliveries, maintenance responsibilities and emergency contacts. Clarify responsibility for gardens, driveways, paths and shared infrastructure. Where services are shared, check lawful metering and charging arrangements and explain them in the occupancy documents.
Assess rental feasibility with recent, genuinely comparable evidence. Distinguish asking prices from achieved rents and compare approval status, condition, access, utility arrangements and inclusions. Obtain property-specific finance, tax, insurance and property-management advice, including expected operating obligations and periods when the premises may be unoccupied.
Choosing a granny-flat builder
Identify the legal entity that will enter the contract, then use the Service NSW register to check the builder or tradesperson licence. Confirm the licence is current, its category covers the proposed work and its holder matches the contract. An ABN, association membership, referral or review score is not a substitute for this check.
Seek recent references for comparable secondary-dwelling projects, particularly where construction type, access, services or conversion work resemble the proposed job. With the owner’s permission, inspect completed work. Ask references about communication, site-cost changes, written variations, defects, documentation and after-completion support.
Provide every tenderer with the same scope and compare:
- specifications, inclusions and exclusions;
- fixed amounts, allowances and provisional sums;
- excavation, retaining and access assumptions;
- utility, drainage and external-work responsibilities;
- planning, certification and inspection responsibilities;
- BASIX products and performance commitments;
- variation and extension-of-time procedures;
- defects, handover documents and statutory warranty information.
Confirm whether the price is based on approved construction documents or an early concept. Identify who will coordinate consultants, respond to council or certifier requests, arrange inspections and provide certificates needed for occupation. Put those responsibilities in the written contract.
Follow the contract and deposit rules outlined in the budgeting section. Read the Consumer Building Guide and verify the statutory warranty information applicable to the contract and work. Keep progress payments tied to documented, completed stages. Record variations in writing, including scope, price and time effects, before varied work proceeds where practicable.
Where home building compensation cover is required, verify the certificate through HBC Check before payment or commencement. Do not accept an application receipt, generic policy or certificate for another entity or site. Retain the contract, approved documents, certificates, variation records, payment evidence, product warranties and maintenance information.
Compare total delivered scope rather than headline price. A tender with unresolved site work, service connections, approval responsibilities or handover documents is not directly comparable with one that includes those items.
Planning and feasibility checklist
- Confirm the address, lot and deposited plan.
- Verify the legal council authority.
- Obtain the title and approval history.
- Confirm the lawful principal dwelling.
- Check zoning and current planning instruments.
- Record relevant mapped controls.
- Obtain a survey and service searches.
- Review easements, covenants and access rights.
- Define the internal, attached, detached or conversion proposal.
- Test both approval pathways with council or a registered certifier.
- Confirm design standards and required reports.
- Select the correct BASIX project type.
- Verify current fees, contributions and authority charges.
- Compare itemised quotes on one documented scope.
- Check licences, contract terms, warranties and HBC evidence.
- Obtain approval before starting work.
- Complete required inspections and certificates.
- Obtain the occupation certificate before occupation.
- Use current tenancy documents if renting.