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 marketing label, construction system or physical appearance.
This guide combines limited statistical context for Combara with statewide planning and building guidance. It does not establish the zoning, consent authority, constraints or development potential of an individual property. Those matters must be checked against the legal parcel, current planning instruments, title information and the proposed design.
The locality evidence is sparse, so the useful focus is a disciplined verification process rather than unsupported claims about local lifestyles, services, hazards or property markets.
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Local granny-flat overview
The supplied canonical record identifies Combara as ABS Suburbs and Localities geography code SAL10990. SAL means the Australian Bureau of Statistics Suburbs and Localities geography. SAL boundaries are statistical approximations based on officially recognised suburb and locality boundaries; they are not cadastral parcels, planning zones or legal evidence of council responsibility.
The record gives the Combara SAL an area of 282.6539 square kilometres and one mesh block. It records its statistical overlap entirely within the ABS local government area named Coonamble. That ABS LGA name must be distinguished from the formal council organisation name, Coonamble Shire Council. The overlap is useful for routing research, but it cannot establish which council or consent authority is responsible for a legal parcel.
The 2021 Census Combara QuickStats reported 28 people and 18 private dwellings. These are historical results from the 2021 Census edition, not current population or housing conditions. Because the recorded population was very low, percentages can be volatile and individual changes can materially affect the results. It would therefore be unsafe to derive generic demographic, rental-demand, market-performance or investment claims from these figures.
The small statistical base also limits meaningful comparison with larger localities. A count for the entire SAL cannot show whether a particular parcel contains a dwelling, has legal access, is serviced or supports residential development. The Census evidence is useful only as dated locality context; it should not be used as a proxy for current property supply, household preferences or development feasibility.
For planning purposes, the property address and lot/deposited-plan details matter more than the SAL name. Start with the NSW Planning Portal Spatial Viewer and then verify the displayed information against current instruments and formal property records. Online mapping is a screening tool rather than a substitute for a title search, survey, planning certificate or written authority advice.
Under the NSW secondary-dwelling guidance, a secondary dwelling operates with a principal dwelling and remains on the same lot. The secondary-dwelling pathway does not create a separately subdividable, titled or saleable residence. A freestanding building is not automatically a secondary dwelling, and an existing garage, shed or studio cannot be treated as approved accommodation without checking its approval history and lawful use.
State guidance identifies secondary dwellings as permitted in residential zones R1, R2, R3, R4 and R5, with possible permissibility in other zones where the applicable local environmental plan allows it. Permissibility is not development approval. Rural and non-residential land requires particular care because local environmental plan provisions may differ from the residential framework.
Council rules and approval pathway
There are two potential approval pathways. A development application is assessed by the responsible council under the applicable planning instruments and assessment requirements. Alternatively, a complying development certificate may be issued by a council or appropriately registered certifier when every relevant standard, prerequisite and mapped eligibility test is satisfied. The NSW complying-development guidance explains this standards-based process and the certifier’s role.
For the Housing SEPP complying-development pathway, NSW guidance identifies a lot area of at least 450 square metres, except where the secondary dwelling is located entirely within an existing dwelling house. This is one bounded eligibility requirement only. It is not a universal minimum for a council-assessed application and is not sufficient by itself to establish complying-development eligibility.
The proposal must be tested against the current State Environmental Planning Policy (Housing) 2021, including its relevant schedule, and the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008. The assessment must also account for mapped exclusions, the principal dwelling, the proposal’s configuration and any other applicable planning instrument. Repealed Affordable Rental Housing SEPP material should not be used as current law.
If parcel records confirm Coonamble Shire Council as the responsible authority, use the council’s development service entry point, local environmental plan material, development control plans and development-application process guidance. Their applicability remains conditional on verification of the legal parcel, current instrument versions and chosen approval pathway.
Before selecting a pathway, obtain or check:
- the title, deposited plan, boundaries and lawful principal-dwelling records;
- easements, covenants, restrictions and legal access;
- zoning and any site-specific planning instrument;
- sewer, wastewater, drainage and utility locations or capacity;
- applicable council application requirements, contribution plans, fees, waste controls, stormwater policies and vehicle-crossing requirements; and
- any mapped or property-specific constraint shown by official evidence.
Planning approval does not necessarily override private title restrictions. Likewise, a map layer does not establish its precise consequence without reference to the governing instrument and proposal. Constraints should be named for a property only after address-level verification rather than assumed across Combara.
Make the pathway decision only after comparing the property evidence with a defined proposal. Record the instrument, map version and documents reviewed, then ask the verified council or registered certifier to identify unresolved eligibility questions. This creates a traceable basis for design work and reduces the risk of preparing drawings for the wrong pathway. If the concept changes from internal to attached or detached work, or begins to rely on an existing outbuilding, repeat the classification and eligibility review before lodging an application.
The Housing SEPP does not itself require additional parking for a secondary dwelling. Existing consent conditions, loss of existing spaces, driveway safety, access design and other applicable controls may still require assessment.
Following approval, the project may require construction certification, appointment of a principal certifier, inspections and compliance evidence. 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, quote, BASIX certificate or builder statement is not a development approval or occupation certificate.
Costs and budgeting
A useful budget begins with the verified site and documented scope. Generic package advertising cannot account for access, ground conditions, servicing, approval requirements, conversion work, external works or specification choices. Obtain current authority charges and itemised quotations rather than applying a suburb-wide estimate.
Build the budget under separate headings:
- title, survey, planning and service investigations;
- design, engineering and specialist reports;
- application, certifier and authority charges;
- contributions where applicable;
- demolition, excavation, retaining and site preparation;
- construction, fixtures and finishes;
- stormwater, wastewater, water, electricity and communications;
- access, paths, fencing, landscaping and waste removal;
- BASIX documentation, inspections and handover certificates;
- insurance, finance expenses and a risk allowance based on identified uncertainty.
Service investigations should precede final siting. Connection distance, network capacity, legal discharge points, machinery access and required authority work may change both design and price. For a proposed conversion, investigate the existing structure’s lawful status and suitability for residential work, including structural, fire-safety, waterproofing, ventilation, insulation and service requirements.
Maintain a budget register that links each allowance to a drawing, quotation, authority response or unresolved question. Separate confirmed amounts from provisional items and identify who must obtain the missing information. Update the register after survey work, planning advice, service investigations and design revisions. This is more useful than adding an unsupported standard percentage because each site’s uncertainty arises from different evidence gaps. It also makes tender comparisons clearer when one contractor includes work that another excludes.
Ask tenderers to price the same drawings and specification. Compare exclusions, provisional sums, site assumptions, approval responsibilities, BASIX commitments, connection work and external works. Record which amounts are fixed, which are allowances and which remain unresolved.
Current 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 current Consumer Building Guide, check the contract’s statutory warranty information and align progress payments with completed work.
Home building compensation cover applies where required for residential building work valued at $20,000 or more, including GST. Before paying money or allowing work to start, use the official HBC Check to verify the certificate, insured contractor, site and work details. Recheck current rules and forms when contracting because regulatory requirements may change.
Design and site considerations
Define whether the proposal will be internal, attached or detached before developing the design. This affects classification, construction interfaces, access, servicing and the correct BASIX secondary-dwelling project type. Where an existing structure is involved, obtain its approval records before relying on it in the concept.
Use an accurate survey showing boundaries, levels, buildings, easements, significant site features and available service information. Test the layout for:
- the relationship with the principal dwelling;
- private open space, daylight and ventilation;
- visual and acoustic privacy;
- safe pedestrian and vehicle access;
- waste storage, clothes drying and maintenance access;
- effects on existing parking and manoeuvring; and
- practical routes for drainage, wastewater and utilities.
Check setbacks, height, floor area, landscaped area, site coverage and earthworks against the exact pathway and current controls. Do not copy dimensions from another council, a superseded instrument or a different development type. For rural or non-residential land, verify the applicable local environmental plan rather than transferring residential assumptions.
Resolve stormwater and wastewater arrangements while testing the footprint. Confirm lawful discharge, authority requirements, utility capacity and the location of infrastructure before excavation. Review the title for interests that may prevent building or connecting services in the preferred location.
Use official mapping to screen the parcel, but discuss bushfire, flooding, biodiversity, heritage, trees, contamination or another constraint only where property evidence shows relevance. If a verified constraint applies, establish the required report, design response and authority consultation before final documentation.
BASIX guidance addresses water, energy use and thermal performance for applicable residential development. Incorporate the resulting commitments into orientation, glazing, shading, insulation, ventilation, fixtures and services. Ensure the approved certificate, drawings, specification and building contract are consistent.
Prefabricated, modular or relocatable construction does not bypass planning, building, BASIX or certification requirements. The same verification sequence applies to a proposed garage or outbuilding conversion: physical fit is not evidence of lawful residential use.
Rental and investment considerations
Rental assessment should begin only after confirming the approved use and occupation documentation. Retain the consent or complying development certificate, approved plans, inspection records and occupation certificate so the premises can be managed by reference to the lawful approval.
A secondary dwelling remains associated with the principal dwelling on one lot. This affects lending, valuation, insurance, management and future sale arrangements. Obtain advice based on the actual title and owner circumstances rather than modelling it as an independently titled property.
Where the approved premises are rented under a residential tenancy, follow NSW Fair Trading’s current residential tenancy agreement guidance and the Residential Tenancies Act 2010. Use the current agreement and processes for bonds, condition reporting, disclosure, repairs, safety obligations and notices.
Do not assume that family occupation, a licence, boarding, short-term accommodation and a standard residential tenancy have identical legal or planning treatment. Identify the intended arrangement and obtain current guidance for that use.
Before occupation, document practical shared-site arrangements, including access, privacy, waste, deliveries, gardens, driveways, maintenance and emergency contacts. If services are shared, establish a lawful and understandable method for allocating charges and maintaining common infrastructure.
Combara’s very small 2021 Census population does not provide a sound basis for estimating current demand or returns. Obtain recent comparable rental evidence from a suitably qualified local professional, distinguish asking prices from achieved rents and verify that comparables have similar approval status, condition, access and inclusions. Seek separate finance, taxation and insurance advice tailored to the owner and proposed occupancy.
Choosing a granny-flat builder
Identify the legal entity proposing to enter the contract, then use the official Service NSW tool to check the builder or tradesperson licence. Match the entity name and licence number to the contract, confirm that the licence is current and check that its category covers the proposed work. An ABN, association membership or online review is not a substitute for this register check.
Request recent references for comparable secondary-dwelling work. Where possible, speak with past clients and inspect completed projects with permission. Ask about documentation, communication, site-cost management, variations, defects and after-completion support.
Give each tenderer the same drawings, reports and specification. Compare:
- inclusions, exclusions, allowances and provisional sums;
- excavation, retaining and access assumptions;
- utility, drainage and external-work responsibilities;
- approval, certification and inspection responsibilities;
- BASIX products and commitments;
- variation and extension-of-time procedures;
- defects, handover documents and statutory warranties; and
- the party responsible for obtaining occupation documentation.
Confirm whether the price is based on approved construction documents or an early concept. Record responsibility for consultants, authority responses and certificates in the contract rather than relying on sales discussions.
Apply the contract and home building compensation checks described in the budgeting section. Read the Consumer Building Guide, verify applicable statutory warranty information, keep agreed variations in writing and confirm the required insurance evidence before payment or work. Evaluate the complete documented scope rather than ranking builders by headline price.
Planning and feasibility checklist
- Confirm the address, lot, deposited plan and registered title.
- Verify the responsible council and consent authority.
- Confirm the lawful principal dwelling and existing-use approvals.
- Check zoning and mapped controls in the Spatial Viewer.
- Read the current planning instruments for the parcel.
- Obtain title, survey, service and drainage information.
- Investigate verified constraints and private restrictions.
- Define the internal, attached, detached or conversion proposal.
- Test both approval pathways with council or a registered certifier.
- Confirm design standards, reports and BASIX classification.
- Check application requirements, charges and contributions.
- Compare itemised quotes on an identical scope.
- Verify licences, contract terms, warranties and insurance evidence.
- Obtain approval before commencing work.
- Arrange certification, inspections and compliance records.
- Obtain the occupation certificate before occupation or use.
- Establish compliant tenancy documents before renting.