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. In New South Wales, secondary dwelling is the formal planning term; the approved use and documents determine the classification, not a builder’s product name or the structure’s appearance.
This guide combines limited Gilgooma statistical context with statewide planning and consumer-protection guidance. It does not establish the controls for an individual address. A legal parcel’s zoning, consent authority, title, existing approvals, mapped constraints and services must be checked before a design or approval pathway is selected.
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This guide is general information only. Obtain property-specific verification of zoning, overlays, title constraints, services and approval requirements before making design, purchase or construction decisions.
Local granny-flat overview
Gilgooma is identified here using Australian Bureau of Statistics locality code SAL11624. SAL means the ABS Suburbs and Localities geography. Its boundaries are statistical approximations created for Census reporting; they are not cadastral boundaries, planning zones or evidence of development rights. SAL does not mean Statistical Area Level 1 and must not be equated with SA1.
The canonical spatial record covers approximately 368.5216 square kilometres and contains one mesh block. It records the Gilgooma SAL as overlapping only the ABS statistical LGA named Coonamble. That is statistical routing context, not proof that Coonamble Shire Council is the consent authority for every legal parcel associated with the locality name. Confirm the parcel’s local government area through current cadastral and planning records before using council instruments or application instructions.
The 2021 Census Gilgooma QuickStats reported 44 people, 10 families and 15 private dwellings. These are historical values from the 2021 Census, not current population, housing-supply or market measures. The very small count also makes broad demographic, rental-demand or investment conclusions unsafe: a few households can materially affect percentages and medians, while Census geography does not describe the characteristics of a particular property.
The verified locality evidence therefore says little about site-level development conditions. It does not establish Gilgooma-wide zoning, lot dimensions, sewer availability, road access, hazards, heritage status or demand for another dwelling. Those matters should not be inferred from the locality’s area, population or statistical LGA overlap.
Under the NSW secondary-dwelling guidance, a secondary dwelling is associated with a principal dwelling and remains on the same lot. This pathway does not create a separately subdividable, titled or saleable residence. A freestanding building is not automatically a secondary dwelling, and an existing shed, garage or studio cannot be treated as habitable without checking its approval history and authorised use.
State guidance identifies residential zones R1, R2, R3, R4 and R5 as zones in which secondary dwellings are permitted. Other zones may allow them through the applicable local environmental plan. Permissibility is only an initial planning question; the exact parcel, proposal and approval pathway must still satisfy the relevant controls. For rural or other non-residential land, use the current local environmental plan rather than transferring residential-zone assumptions.
Start address-level research with the NSW Planning Portal Spatial Viewer, then compare its displayed information with the in-force planning instrument, title, deposited plan and survey. Online mapping is a screening tool. Formal property records and advice from the verified consent authority or an appropriately qualified professional are needed where boundaries, controls or existing approvals are uncertain.
Council rules and approval pathway
A secondary dwelling may be assessed through a development application or, where every statutory requirement is met, as complying development. A development application is assessed by the responsible council or other consent authority under the applicable environmental planning instruments. A complying development certificate may be issued by a council or registered certifier, but it is a standards-based approval rather than an exemption from planning rules.
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 entirely within an existing dwelling house. This is one bounded eligibility condition only. It is not a universal minimum for a council-assessed development application and is not sufficient by itself to establish complying-development eligibility.
Test a proposed complying-development pathway against current Schedule 1 of the State Environmental Planning Policy (Housing) 2021, the relevant provisions of the Codes SEPP 2008, mapped exclusions and all site-specific standards. The Department’s complying-development guidance explains the role of the certifier and the need to comply with certificate conditions. Superseded Affordable Rental Housing SEPP material should not be used as current law.
If parcel records confirm Coonamble Shire Council as the responsible organisation, use its official development entry point, local environmental plan material, development control plans and development-application process. Their applicability remains conditional on verification of the legal parcel and current consent authority. Do not rely on the ABS LGA name alone.
Before choosing a pathway, identify the current zone and all applicable planning instruments. Check the title and deposited plan for easements, covenants and restrictions; obtain a survey; locate sewer, drainage and other utilities; confirm legal access; and review the approval history of the principal dwelling and any structure proposed for conversion. Planning approval may not displace private title restrictions or authorise interference with utility assets.
Use official property information to investigate only the constraints relevant to the address. These may include mapped environmental, hazard, heritage, infrastructure or land-use controls, but no constraint should be asserted for Gilgooma generally without area-wide official evidence. The authority or certifier can identify the reports and design responses required for verified constraints.
The Housing SEPP does not itself require additional parking for a secondary dwelling. Existing consent conditions, removal of existing parking, safe access, driveway design and local requirements can still affect the proposal. Also confirm current council requirements for stormwater, wastewater, waste storage, vehicle crossings, application documents, contributions and fees.
Approval is followed by the applicable construction certification, inspections and certificate conditions. Service NSW explains that an occupation certificate is required before a new building is occupied or used, or before an existing building is used following an approved change of use. A concept plan, quotation, BASIX certificate or builder statement is not a planning approval or occupation certificate.
Costs and budgeting
A useful budget begins with an investigated site and a documented scope. Generic package prices cannot account for title issues, access, ground conditions, approval requirements, service distances, conversion work or the selected finishes. Obtain current charges from the verified council, certifier, Planning Portal and service authorities instead of relying on an undated allowance.
Build the budget under separate headings:
- title, planning-certificate, survey and service investigations;
- design, engineering and specialist reports;
- application, certifier, authority and contribution charges where applicable;
- demolition, clearing, excavation, retaining and site preparation;
- building work, fixtures, finishes and BASIX commitments;
- stormwater, wastewater, water, electricity and communications connections;
- access, paths, fencing, landscaping and waste removal;
- inspections, certificates, insurance and handover documents; and
- a project-specific risk allowance for unresolved scope.
Ask each tenderer to price the same drawings and specification. Compare exclusions, provisional sums, site assumptions, service allowances, approval responsibilities and external works. Confirm whether rock, unsuitable soil, restricted machinery access, utility upgrades or rectification of existing structures is included. For conversions, allow for investigation of structural capacity, fire safety, waterproofing, ventilation, insulation and lawful existing use.
The current Building Commission NSW contract guidance requires a written contract for residential building work costing more than $5,000, with more extensive large-job contract requirements above $20,000. The maximum deposit is 10%. Read the Consumer Building Guide, verify that progress payments correspond to completed stages and review the statutory warranty information and clauses applicable to the work before signing.
Home building compensation cover applies where required for residential building work valued at $20,000 or more, including GST. Check the certificate through the official HBC Check before paying money or permitting work to begin. Match the legal entity, property and contracted work to the certificate, and retain the evidence with the contract records.
Design and site considerations
Define whether the proposal will be internal, attached or separate before developing the layout. That choice affects its documentation, building interfaces, access, servicing and the correct BASIX secondary-dwelling project classification. Where an existing structure is involved, first confirm its lawful use and approval history.
Prepare an accurate survey showing boundaries, levels, buildings, easements, significant trees, access and known services. Test the design against the principal dwelling and the usable parts of the site. Consider privacy, overlooking, daylight, ventilation, noise, private open space, waste storage, clothes drying, deliveries, maintenance access and safe movement between the street and both dwellings.
Setbacks, floor area, height, landscaped area, site coverage and earthworks must be checked against the chosen approval pathway and current instruments. Do not copy a design standard from another council, an obsolete instrument or a different development type. Resolve effects on existing parking and vehicle manoeuvring as part of the site design.
Confirm stormwater discharge, wastewater arrangements, utility capacity and connection approvals before fixing the footprint. Existing service locations may affect excavation and building placement. If the verified property information identifies a relevant constraint, obtain the necessary specialist advice early enough to influence siting and construction rather than treating it as a late compliance exercise.
The NSW Planning Portal’s BASIX guidance covers water, energy use and thermal performance. Integrate required commitments into orientation, glazing, shading, insulation, ventilation, fixtures and services. Ensure the approved certificate, drawings, specification and building contract describe the same commitments.
Prefabricated, modular or relocatable construction does not bypass planning, building, certification or occupation requirements. Likewise, physical room for a dwelling does not establish planning suitability. Have the verified controls and site evidence shape the design before seeking fixed construction pricing.
Rental and investment considerations
Consider rental use only after confirming the approved classification, completed work and required occupation certificate. A utility connection or practical ability to live in a structure does not establish lawful residential occupation. Keep the approval, approved plans, certificates and handover documents available for property management and insurance enquiries.
A secondary dwelling remains on the same lot as the principal dwelling. Its same-lot status affects management, privacy, finance, insurance and future sale decisions. Obtain advice based on the actual title and proposed occupancy rather than modelling it as an independently titled property.
Where the approved premises are let under a residential tenancy, use current NSW Fair Trading guidance on residential tenancy agreements and the in-force Residential Tenancies Act 2010. Check the current agreement, bond, condition-report, disclosure, repair, safety and notice requirements before advertising or granting occupation.
Family occupation, a licence, boarder arrangements, short-term accommodation and a standard residential tenancy are not necessarily governed in the same way. Confirm the planning and tenancy treatment of the intended arrangement with the relevant authority or adviser.
Plan how occupants will share the site. Address separate access, visual and acoustic privacy, lighting, deliveries, waste storage, gardens, driveways, maintenance and emergency contacts. Document responsibility for shared infrastructure. If utilities are shared, establish a lawful and transparent method for metering or allocating charges.
The 2021 Census figures are too small and dated to support a reliable Gilgooma rent or demand assessment. Obtain current, comparable local evidence and distinguish asking prices from achieved rents. Discuss the actual proposal with the lender, insurer, property manager, tax adviser and financial adviser before committing to a rental strategy.
Choosing a granny-flat builder
Identify the legal entity that will enter the contract, then use the official Service NSW tool to check the builder or tradesperson licence. Confirm that the licence is current, its category covers the proposed work and its details match the quotation and contract. An ABN, industry membership or review profile is not a licence check.
Request recent references for comparable secondary dwellings, preferably involving similar access, servicing and construction conditions. With the owner’s permission, inspect completed work. Ask former clients about communication, variations, documentation, defects and post-completion service as well as appearance.
Give each tenderer the same drawings, reports and specification. Compare:
- the contracting entity and nominated licence details;
- inclusions, exclusions, allowances and provisional sums;
- excavation, retaining, access and ground-condition assumptions;
- drainage, utilities and external works;
- approval, certification and inspection responsibilities;
- BASIX products and performance commitments;
- variation and extension-of-time procedures;
- defects, statutory warranties and rectification processes; and
- certificates, manuals, warranties and other handover records.
Confirm whether the quotation is based on a concept or approved construction documents. Record who will coordinate consultants, answer authority requests and obtain the documents required for occupation. Oral assurances should be incorporated into the written scope where they are intended to form part of the agreement.
Use the contract required by current Building Commission NSW guidance. Read the Consumer Building Guide and verify that the contract contains the required statutory warranty information. Check payment stages, variations, insurance, dispute procedures and termination provisions, and obtain independent advice on unclear terms. Keep signed contracts, variations, invoices, inspection records and certificates together.
Verify required home building compensation evidence through HBC Check before making a payment or allowing work to start. Do not substitute an application receipt, unrelated policy or the builder’s general insurance certificate. Assess the complete delivered scope rather than selecting a tender solely because its headline price is lowest.
Planning and feasibility checklist
- Confirm the address, lot, deposited plan, title and lawful principal dwelling.
- Verify the consent authority for the legal parcel.
- Check zoning and mapped controls in the Spatial Viewer.
- Review the current local environmental plan and development control plan.
- Obtain the title search, survey, service information and approval history.
- Investigate relevant easements, restrictions, access and site constraints.
- Define the proposal as internal, attached, separate or a conversion.
- Test both approval pathways with council or a registered certifier.
- Confirm design standards, BASIX classification and required reports.
- Obtain current application, authority, certification and contribution charges.
- Compare itemised quotations on an identical documented scope.
- Verify licences, contract terms, statutory warranties and HBC evidence.
- Secure the required approval before starting work.
- Complete required inspections and retain all certificates.
- Obtain the occupation certificate before occupation or use.
- Establish the correct tenancy process before renting the dwelling.