Bobin Granny Flat planning starts with the property, current planning controls and a realistic project brief. Use this guide to identify the checks to complete before design or construction commitments are made.
Bobin Granny Flat: planning essentials
A well-scoped project considers approval pathways, site constraints, services, budget and long-term use together.
In New South Wales, the formal planning term is secondary dwelling; “granny flat” is common reader and search language. A secondary dwelling is self-contained accommodation established with a principal dwelling on the same lot and may be within, attached to or separate from that dwelling. Its classification and lawful use depend on approved documents and current planning requirements, not its marketing name or construction method.
This guide combines limited Bobin statistical context with statewide planning guidance. It cannot establish what is permitted on a particular property. Before choosing a design or contractor, identify the legal parcel and verify its council, zoning, planning instruments, title restrictions, services, mapped controls and approval pathway.
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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
Bobin is recorded as ABS Suburbs and Localities geography code SAL 10426. SAL means Suburbs and Localities, an Australian Bureau of Statistics statistical geography whose boundaries are approximations used to organise Census and other data. SAL boundaries are not cadastral boundaries and do not identify a parcel’s zoning, consent authority or development rights. SAL must not be confused with Statistical Area Level 1 or SA1.
The canonical locality record covers approximately 52.2748 square kilometres and contains two mesh blocks. Its recorded area overlaps the ABS statistical LGA named Mid-Coast. This is statistical context only: an ABS LGA name is not the same thing as the formal council organisation name. The source pack identifies that organisation as MidCoast Council, but responsibility for an address still needs confirmation through official property and local-government systems. The overlap does not prove that the council administers a particular title or will assess a particular application.
The 2021 Census Bobin QuickStats recorded 141 people, 40 families and 74 private dwellings, with a median age of 55. These are historical figures from the 2021 Census, not current population or housing estimates. The small counts and statistical boundary also make broad demographic, housing-demand or market conclusions unsafe. They provide locality scale and context only and say nothing about an individual property’s planning potential.
NSW guidance says secondary dwellings are permitted in residential zones R1, R2, R3, R4 and R5 and may be permitted in other zones under the relevant local environmental plan. Permissibility is not approval. For rural or other non-residential land, check the applicable local environmental plan rather than transferring residential-zone assumptions. Some local instruments contain special rural secondary-dwelling provisions, and their application varies.
A secondary dwelling must remain associated with the principal dwelling on the same lot. This pathway does not create a separately subdividable, separately titled or independently saleable residence. A freestanding cabin, modular unit, converted shed or fitted-out garage is not automatically a lawful secondary dwelling simply because it can accommodate residential facilities.
For a Bobin property, first establish:
- the street address, lot and deposited plan;
- the council responsible for the legal parcel;
- whether a lawful principal dwelling exists;
- the current zone and applicable planning instruments;
- the approval history of structures proposed for conversion;
- title easements, covenants and restrictions;
- legal access and the location of utilities and drainage assets; and
- any constraints shown by official parcel-level records.
The NSW Planning Portal Spatial Viewer is a useful initial mapping tool, while the MidCoast Council development gateway provides council information if that organisation is verified for the address. Mapping should be reconciled with title documents, survey information and current formal advice. Planning consent may not remove a private title restriction.
Council rules and approval pathway
A secondary dwelling may require a development application, or it may qualify as complying development if every applicable standard and exclusion test is satisfied. Confirm the route with the verified council or an appropriately registered certifier before describing a proposal as complying development.
A development application is assessed by the council responsible for the parcel. If MidCoast Council is confirmed, its official planning framework and development-application process are starting points. Applicability of any local environmental plan, development control plan, contribution plan, policy or fee schedule must still be checked for the legal parcel and proposal.
Complying development is a standards-based approval process. A complying development certificate may be issued by a council or registered certifier only where all relevant requirements are met. The official complying-development guidance explains the pathway and certifier’s role. A certifier cannot waive a standard or mapped exclusion.
For the secondary-dwelling complying-development pathway under the Housing SEPP, NSW guidance identifies a lot area of at least 450 square metres, except where the secondary dwelling is entirely within an existing dwelling house. This is one bounded eligibility test, not a universal minimum for a development application and not sufficient by itself. Check Schedule 1 of the current State Environmental Planning Policy (Housing) 2021, the Codes SEPP, mapped exclusions and every site and design standard applying to the proposal.
Do not adopt floor-area, setback, height, site-coverage, landscaped-area or earthworks figures from an old guide or another project. Their scope depends on the current instrument, zone, pathway, site and configuration. Official NSW secondary-dwelling guidance also states that the Housing SEPP does not itself require additional parking for a secondary dwelling. Existing parking, access, driveway design and consent conditions may nevertheless affect the project.
Before lodging, obtain written direction about required surveys, plans, engineering, drainage, waste arrangements, authority approvals, specialist reports, fees, contributions and vehicle-crossing requirements. A concept plan, quote, BASIX certificate or builder statement is not development approval.
After approval, follow all pre-commencement conditions, appoint the required certifier, arrange applicable inspections and retain compliance records. Service NSW explains that an occupation certificate is required before occupying or using a new building or changing the use of an existing building. The project approval and certifier determine the required inspections and evidence.
Costs and budgeting
There is not enough verified locality-specific evidence to publish a reliable Bobin build price. Advertised packages cannot account for a parcel’s access, ground conditions, services, design, approval route or external works. Build the budget from documented site information and compare quotes against the same drawings and specification.
Allow separately for:
- title, survey, service searches and planning investigations;
- design, engineering, BASIX and specialist consultants;
- council, Planning Portal, authority and certifier charges;
- contributions where the applicable plan requires them;
- demolition, clearing, excavation, retaining and disposal;
- foundations, construction, fixtures, appliances and finishes;
- water, sewer, stormwater, electricity and communications work;
- access, paths, fencing, landscaping and site reinstatement;
- inspections, certificates, insurance and handover records; and
- unresolved risks identified through investigation.
Cost sensitivity can arise from slope, restricted construction access, difficult ground, long service routes, drainage design, protected assets, work near the occupied principal dwelling or deficiencies uncovered during a conversion. Prefabricated and modular systems may alter delivery, but they do not bypass site works, approvals, connections, certification or occupation requirements.
Request itemised, like-for-like tenders. Identify fixed inclusions, exclusions, provisional sums, prime-cost items and owner-supplied work. Allocate responsibility for approvals, engineering, BASIX commitments, excavation, spoil, retaining, utility connections, stormwater, landscaping and damage rectification. Verify current fees directly with the confirmed council, certifier and service authorities rather than carrying assumptions from another address.
Consumer-protection costs and documents also belong in the budget. Building Commission NSW contract guidance states that residential building work over $5,000 requires a written contract, work over $20,000 attracts the more extensive large-job contract requirements, and the maximum deposit is 10%. Home building compensation cover applies to residential building work valued at $20,000 or more including GST, subject to current statutory requirements. Where required, verify the certificate through the official HBC Check before making a payment or allowing work to begin.
Bobin Granny Flat: council and site checks
Confirm property-specific requirements with the responsible council or certifier before relying on general guidance.
Design and site considerations
Begin design with an accurate survey, approval history and service information. Compare internal, attached and separate configurations by how they affect both dwellings, not merely by whether a building footprint appears to fit. Confirm that any existing structure was lawfully approved for its current use before proposing residential conversion.
Apply the design standards identified for the approval pathway above. A coordinated concept should address:
- safe pedestrian access and emergency access where relevant;
- privacy between living areas, bedrooms and outdoor spaces;
- overlooking of neighbouring properties;
- daylight, ventilation, orientation and shading;
- useful open space for occupants of both dwellings;
- waste storage, collection routes and clothes drying;
- maintenance access and equipment locations;
- existing parking, manoeuvring and the vehicle crossing; and
- practical utility, metering and drainage arrangements.
Locate sewer, water, electricity, communications and stormwater assets before fixing the building position. Check easements, authority clearances, legal access and any required approvals for work near infrastructure. Stormwater disposal needs an accepted design; the presence of a boundary or nearby drain does not demonstrate a lawful connection point.
Use the Spatial Viewer and other official records to identify potential parcel-level issues. Investigate bushfire, flooding, biodiversity, heritage, contamination, trees, coastal hazards, acid sulfate soils, mine subsidence or other overlays only where official evidence indicates relevance. Bobin’s locality identity does not establish that any constraint is present or absent. Commission the appropriate specialist assessment when the property evidence or approval authority requires it.
BASIX addresses water, energy use and thermal performance for relevant residential development. Integrate its commitments into orientation, glazing, insulation, ventilation, fixtures and services before tendering. The Planning Portal’s secondary-dwelling BASIX guidance distinguishes conversions, new attached or separate work, and projects involving new principal and secondary dwellings together. Select the classification that matches the documented project.
A modular unit, tiny-home product or converted outbuilding may still require planning approval, building certification, BASIX work and an occupation certificate. Ask the designer and certifier to document how the proposed construction and use fit the approved classification.
Rental and investment considerations
Confirm lawful approval and occupation status before treating the accommodation as rentable. Obtain the development consent or complying development certificate, approved plans, inspection records and occupation certificate, then check that the completed building corresponds with those documents. Previous informal occupation is not evidence of lawful residential use.
The secondary dwelling remains part of the same legal lot as the principal dwelling. Its same-lot status should be disclosed to finance, insurance, taxation, valuation and property-management advisers so that their advice reflects the actual arrangement.
If the approved dwelling is let under a residential tenancy, use current NSW Fair Trading residential-tenancy guidance for written agreements, standard terms and landlord and tenant obligations. The governing statute is the current Residential Tenancies Act 2010. Family occupation, boarding, licensing, short-stay accommodation and standard residential tenancies should not be treated as legally interchangeable; identify the intended arrangement and obtain relevant advice.
For a rental assessment, use recent evidence for genuinely comparable, lawfully occupiable accommodation. Asking prices do not prove achieved rent. Examine differences in condition, privacy, parking, access, utility arrangements and outdoor space, and obtain advice based on current local evidence rather than the historical Census figures.
Resolve shared-property arrangements before letting:
- define access, parking and outdoor areas;
- document responsibility for bins, gardens, paths and common equipment;
- establish lawful methods for charging shared utilities;
- confirm maintenance and repair access; and
- tell the insurer about the building and intended rental use.
Window placement, acoustic separation, lighting, entrances and screening can materially affect both households. Address these matters during design rather than leaving them to tenancy management.
Choosing a granny-flat builder
Seek comparable tenders only after the scope, site information and likely approval pathway are sufficiently developed. A package quote prepared without a survey, service data or clear responsibility schedule may exclude substantial work.
Identify the exact legal entity proposing to contract and perform the building work. Use the official NSW builder and tradesperson licence check to verify its current licence status and category. Check relevant specialist trades as appropriate. An ABN, association badge, advertising claim or review score is not a licence check.
Ask for recent secondary-dwelling references involving comparable construction and inspect completed work where permission is available. Ask former clients about supervision, communication, variations, service connections, site protection, defects and delivery of certificates. References demonstrate experience, not suitability of the same design for the Bobin parcel.
Compare each tender against a written schedule covering:
- drawings, specification, engineering and approvals;
- certification, inspections and occupation documentation;
- BASIX products and installation responsibilities;
- excavation, rock, spoil, retaining and site access;
- utilities, sewer, drainage and stormwater;
- provisional sums, prime-cost items and exclusions;
- fixtures, appliances, finishes and external works;
- variations, progress payments and time allowances;
- defect rectification, handover records and maintenance information; and
- protection and reinstatement of the existing property.
Use the contract required for the work, read the Consumer Building Guide and attach all agreed plans and specifications. Do not sign unexplained blanks. Keep progress payments aligned with documented contract stages and completed work.
Where home building compensation cover is required, check the policy certificate against the contractor, insured owner, property and scope through HBC Check before payment or commencement. Also verify the statutory warranty information applicable to the work, including current warranty rights, periods, exclusions and the process for notifying defects. Record the builder’s contractual warranty obligations separately from statutory protections, and retain dated defect notices and responses.
Before construction, notify the property insurer and clarify cover for the existing dwelling, works, site access and intended finished use. At handover, collect approvals, certificates, warranties, manuals, keys, product records and final plans rather than relying on a verbal assurance that the file is complete.
Planning and feasibility checklist
- Confirm the address, lot, deposited plan, ownership and title arrangement.
- Verify the responsible council through official parcel records.
- Obtain approval records for the principal dwelling and structures proposed for conversion.
- Check zoning and mapped controls in the Spatial Viewer.
- Review the current local environmental plan, development control plan and State policies.
- Order title, survey, service and drainage information.
- Investigate relevant easements, restrictions, access issues and mapped constraints.
- Define whether the proposal is internal, attached, separate or a conversion.
- Test development-application and complying-development routes with the council or certifier.
- Confirm required plans, reports, BASIX classification, fees and contributions.
- Compare coordinated, itemised tenders and documented exclusions.
- Check licences, contract requirements, statutory warranty information and HBC cover.
- Obtain approval before starting work.
- Complete required inspections and approval conditions.
- Obtain the occupation certificate before occupation or use.
- Set up any tenancy using current NSW Fair Trading requirements.
- Retain approvals, certificates, contracts, warranties and final plans with the property records.
Next steps for your Bobin Granny Flat
Before progressing a Bobin Granny Flat, compare the evidence in our planning guides and use the NSW suburb finder to locate relevant local guidance.
A successful Bobin Granny Flat proposal should be checked against the current planning instrument, title constraints, servicing needs and a documented project budget.