Frequently Asked Questions
DA, CDC, BASIX & Architectural Services in Sydney — Answered by giantA

giantA Pty Ltd is a Sydney-based building design and consultancy practice covering the full pre-construction journey for NSW residential and small commercial projects. Our scope is grouped into four service stages:

• Design — Architectural Services and drafting for new homes, duplexes, granny flats, extensions, townhouses and apartments.
• Approvals — full documentation and lodgement for DA and CDC pathways via the NSW Planning Portal, including DA vs CDC pathway advice and RFI responses.
• Compliance — BASIX and NatHERS certificates prepared in-house by Franz Phan, a NatHERS Accredited Assessor and Registered Design Practitioner under the NSW Design and Building Practitioners Act 2020.
• Construction Certificate — coordinating engineering, specifications and certifier liaison through to CC. See Information Drawing Sheets for council documentation standards.

We serve Sydney metro and regional NSW remotely, with projects coordinated through the NSW Planning Portal.

A Development Application (DA) is assessed by your local council against the LEP and DCP. It suits complex, non-standard, or constrained sites (heritage, bushfire, multi-dwelling). Typical determination is 30–90+ days depending on council, with 14-day public notification. A Complying Development Certificate (CDC) is a fast-track approval for straightforward residential work that fully meets the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 (Codes SEPP). A CDC can be issued by council or a private certifier in as little as 10–20 days with no neighbour notification required.

Side-by-side:

• Approver — council (DA) vs council or private certifier (CDC)
• Timeline — 30–90+ days (DA) vs 10–20 days (CDC)
• All-in cost — $5,000–$15,000+ (DA) vs $3,000–$6,000 (CDC)
• Public notification — required (DA) vs not required (CDC)
• Typical use — complex, heritage, duplex, multi-dwelling (DA) vs standard homes, granny flats, renovations, pools (CDC)

For a worked example of each pathway, see our DA vs CDC guide and the supporting DA/CDC document checklist.

DA cost in Sydney comes in three components, typically totalling $5,000–$15,000+ all-in for residential work:

• Council DA fee — set by the council and scaled to the estimated cost of works. For a $500K project, expect $1,500–$3,000. Each council publishes a yearly Fees and Charges schedule.
• Supporting reports — $2,000–$8,000 depending on site triggers: Statement of Environmental Effects (SEE), BASIX, stormwater, bushfire (BAL), acoustic, arborist, heritage.
• Architectural drawings — the council-ready design and documentation package. giantA provides a fixed-fee quote after reviewing your site.

The most expensive DA is the one you have to lodge twice — more than a third of DAs are delayed by Requests for Further Information that typically add 30–50 days and extra drawing revisions. For the timeline and decision framework, see our DA vs CDC guide, and check your council's median timeframe on the NSW Faster Assessments league table.

BASIX (Building Sustainability Index) is the NSW Government's mandatory sustainability assessment for residential development. It sets minimum water, energy, and thermal comfort targets that must be met before a DA or CDC can be approved.

You need a BASIX certificate when you:

• Build any new dwelling (house, duplex, granny flat, apartment)
• Undertake alterations or additions valued at $50,000 or more
• Install a swimming pool or spa over 40,000 litres

Thermal comfort is demonstrated via a NatHERS star rating — currently a 7-star minimum for new dwellings under the NSW variation of the NCC. giantA prepares BASIX and NatHERS in-house through Franz Phan, a NatHERS Accredited Assessor — both certificates are bundled into our DA and CDC packages. Details at BASIX & NatHERS assessments.

Maybe — under the NSW Housing SEPP, the default minimum lot size for a dual occupancy (duplex) is 400 sqm, but your council's Local Environmental Plan can set that figure higher or (in some LGAs) lower.

Key constraints to check:

• Zoning — R2 Low Density and R3 Medium Density are the most common; R1 and some rural zones also permit dual occupancy
• Minimum lot size — typically 400 sqm under the Housing SEPP, but confirm against the LEP for your LGA
• Setbacks & FSR — your council's DCP sets setbacks, height, and floor space ratio which determine the buildable envelope
• Easements & covenants — sewer, drainage and Section 88B instruments can eliminate the building footprint even on a conforming lot
• Site constraints — bushfire (BAL), flooding, and heritage overlays can push a duplex from CDC into DA territory

Verify your zoning and constraints using the NSW Planning Portal Spatial Viewer, then check our free duplex floor plans for layouts that fit common envelopes. We'll confirm viable size and pathway in a free feasibility call.

Realistic DA approval timelines in NSW range from 30 days to 6+ months, depending on the council and project complexity.

The NSW Government's Faster Assessments Program publishes median determination times for every council — for 2026, medians in Greater Sydney range from about 50 to 110 days. As an indicative guide:

• Simple residential (CDC-eligible but lodged as DA) — 30–60 days
• Standard residential DA — 60–90 days
• Complex, heritage or BAL-affected DA — 90–180 days
• CDC via private certifier — 10–20 days (for comparison)

The most common cause of delay is a council Request for Further Information (RFI) — roughly one in three DAs receive an RFI, and each typically adds 30–50 days. Complete submissions through the NSW Planning Portal with a full SEE and BASIX are the main RFI reduction strategy; details in our DA vs CDC guide.

A Registered Design Practitioner (RDP) is a designer registered under the NSW Design and Building Practitioners Act 2020 to make declared designs for certain classes of building work. An RDP declaration confirms the design complies with the Building Code of Australia and other applicable standards.

Registration is mandatory when designing:

• Class 2 buildings (multi-residential apartments)
• Class 3 buildings — boarding houses, hotels, aged care, student accommodation
• Class 9c buildings — certain residential care facilities

Class 1a dwellings (single houses) do not require RDP declarations under the Act — but using an RDP on any project raises documentation quality because practitioners must maintain insurance, CPD, and demonstrate compliance expertise to NSW Fair Trading's Building Commission NSW register.

Franz Phan, director of giantA, is a Registered Design Practitioner with 15+ years of NSW residential experience. Verify any practitioner's registration on the NSW Fair Trading public register before engaging them.

Yes — we take building design and documentation work from every Australian state and territory, with New South Wales as our primary focus. Our office is in Parramatta CBD, but projects are coordinated remotely through state planning portals (NSW Planning Portal, plus the equivalent portals in VIC, QLD, SA, WA, TAS, ACT and NT), so location is rarely a blocker for documentation and compliance work.

Our workload concentrates in NSW:

• Greater Sydney — Parramatta, Blacktown, Penrith, Campbelltown, Liverpool, Hills District, Inner West
• Central Coast, Hunter and Illawarra — Gosford, Wyong, Newcastle, Wollongong, Shellharbour
• Regional NSW — Blue Mountains, Southern Highlands, and beyond

Other states and territories — we accept projects in Victoria, Queensland, South Australia, Western Australia, Tasmania, the ACT and the Northern Territory on a case-by-case basis, typically where the work is design-led or compliance documentation rather than DA/CDC lodgement (planning legislation is state-specific). Where state registration is required to declare work, we partner with locally registered practitioners so declarations stay compliant.

RDP declarations under the NSW Design and Building Practitioners Act 2020 apply only to NSW Class 2, 3 and 9c buildings — for interstate regulated classes we coordinate the relevant local practitioner. Site inspections, video consultations, and final coordination with local certifiers are included in every package. Book a free consultation with your project address and we'll confirm scope and coverage.

giantA Pty Ltd is registered with NSW Fair Trading to design buildings of all scales — from single dwellings through to large multi-residential and mixed-use developments — and our director Franz Phan holds Registered Design Practitioner status under the NSW Design and Building Practitioners Act 2020, which authorises declared designs for apartments, boarding houses, and residential care facilities.

For context, the National Construction Code (NCC) classifies buildings into Classes 1–10. giantA's work concentrates on:

• Class 1a and 1b — single houses, duplexes, boarding houses, small hostels
• Class 2 — multi-unit residential apartment buildings
• Class 3 — boarding houses, hotels, aged-care and student accommodation
• Classes 5, 6, 7 and 9c — small-scale commercial, retail, car park and care facilities
• Class 10 — non-habitable structures including carports, garages and fences

For Class 2, 3 and 9c work, our RDP declarations are lodged through the NSW Planning Portal as part of the CC process. Class 1a residential work does not require RDP registration under the Act, but we apply the same documentation standard across all classes. Contact us with your project type and we'll confirm scope before quoting.

Get a quote in 3 steps:

1. Book a free consultation via our online booking form — pick a 15-minute or 60-minute slot that suits you, and we'll come prepared with your site's planning snapshot.
2. Receive your quote — itemised and fixed-fee by stage, within 24–48 hours of the call.
3. Approve and start — once you sign off, we begin the feasibility study and your project's drawings are underway within the week.

Prefer email or phone first? Email info@giantA.com.au or call +61 488 880 787.

Price-match guarantee: if you hold a written quote from another NSW practitioner for the same scope of work, share it with us — where scope is genuinely comparable we will match or beat it by at least 10%.

A Complying Development Certificate (CDC) is the fastest NSW approval pathway. Per the NSW Planning Portal:

• Standard CDC: as little as 20 days from lodgement to determination
• NSW Housing Pattern Book CDC pathway: as little as 10 days

The timeline is driven by the certifier's review of your documents against the Codes SEPP — there's no neighbour notification, no council merit assessment, and no Request for Further Information (RFI) loop, provided your submission is complete. Most of giantA's CDC packages reach determination within the 20-day window when plans are fully code-compliant at lodgement. For a full pathway comparison, see our DA vs CDC guide.

BASIX certificate fees have two components:

• NSW Government BASIX fee — $50 per new dwelling (single house, apartment unit); lower fees apply for alterations and additions. Paid directly to the NSW Government.
• NatHERS thermal simulation — required to demonstrate the thermal comfort target within BASIX. Industry fees typically $300–$800 per dwelling depending on design complexity.

Total realistic budget for a residential BASIX + NatHERS package on a single dwelling: $350–$900, including the government fee. giantA coordinates the NatHERS simulation and lodges BASIX as part of our energy assessment service.

All-in CDC cost for a typical residential project:

• Private certifier fee — $1,500–$3,000 depending on project scale (this is the certifier's professional fee, not a government charge)
• Architectural plans — variable; our drafting service prices from $2,500 for code-compliant residential work
• BASIX + NatHERS — $350–$900 (see Q12)
• Supporting reports — site plan, structural engineering where required ($500–$2,000)

Realistic all-in: $3,000–$6,000 for a standard complying development. That's typically one-third the cost of an equivalent DA, primarily because no Statement of Environmental Effects or specialist environmental reports are required. See our DA vs CDC guide for the full side-by-side cost comparison.

Most NSW residential blocks allow a granny flat (secondary dwelling) as complying development under the NSW Housing SEPP — but the answer depends on lot size, zoning and a handful of site standards. NSW Planning's Secondary Dwellings page is the authoritative source and is updated as the Housing SEPP changes — check there first for any recent amendments.

The current NSW baseline (as at 2026, per the Housing SEPP and Codes SEPP):

• Lot size: at least 450 m² to build a secondary dwelling as complying development. Smaller lots can only apply via a DA — with one exception: a secondary dwelling located entirely within an existing house (conversion, not extension) doesn't need the 450 m² minimum.
• Zoning: permitted in R1, R2, R3, R4 and R5 residential zones; other zones depend on your council's LEP.
• Floor area: the secondary dwelling itself is capped at 60 m² GFA (excluding parking), and the combined house + granny flat must still fit within your LEP's floor space ratio (typically 0.5:1 in low-density zones).
• Height and storeys: max 8.5 m, up to two storeys allowed — same as a standard dwelling house.
• Setbacks: same as for a dwelling house — front setback follows the principal dwelling line; side and rear setbacks vary by lot width (typically 0.9 m side for narrow lots and 1.5–3 m for wider lots under the Codes SEPP).
• Parking: the Housing SEPP does NOT require additional parking for a secondary dwelling, but you can't remove existing on-site parking serving the principal dwelling without council sign-off.
• No subdivision: the lot cannot be subdivided after a secondary dwelling is built — both remain on one title.
• Site constraints: bushfire-prone land (BAL-40 or Flame Zone), flood-affected areas and some heritage conservation areas push the project from complying development into DA territory.

If your block doesn't fit complying development, a DA with your local council may still be possible — the pathway depends on the specific constraint. Check your zoning and overlays first using the NSW Planning Portal Spatial Viewer, then book a free consultation and we'll confirm the viable pathway with your address.

Generally no under standard LEPs — R2 Low Density Residential typically permits only:

• Single dwelling houses
• Dual occupancies (attached or detached)
• Secondary dwellings (granny flats)

Multi-dwelling housing (townhouses and terraces) is usually permitted in R3 Medium Density or higher zones. However, some councils have introduced R2 variations allowing manor homes and multi-dwelling housing under their LEPs — check your council's Land Use Matrix via the NSW Planning Portal.

If you're considering townhouse development on R2, the two routes are: (a) verify your council's specific R2 controls allow it (some do since the 2023 Low-Rise Housing Diversity Code), or (b) seek a rezoning/planning proposal — a longer process. giantA can review your zoning and outline realistic options before you engage specialists.

A Development Application consent in NSW is valid for 5 years from the date of determination. This is set under the Environmental Planning and Assessment Act 1979 (s 4.53).

Key points:

• You must physically commence the work (not just obtain certificates) before the 5-year lapse date
• "Commencement" has been interpreted narrowly by courts — site works alone may not be sufficient
• The 5-year period can be reduced by the consent authority in some cases, or extended via a Section 4.55 modification application
• COVID-era extensions allowing up to 7 years for some DAs ended in 2023

If your DA is approaching expiry, contact us before the lapse date — options exist but are time-sensitive.

Almost always yes, via one of two pathways:

• Exempt development — only for very minor extensions (e.g. small decks or pergolas below threshold). Most extensions exceed exempt limits.
• CDC — the typical route for residential extensions in Sydney. Your extension must meet Codes SEPP standards for height (max 8.5m), setbacks, floor space ratio, and site coverage.
• DA — required if your extension exceeds CDC standards, affects heritage, is in a foreshore or environmentally sensitive zone, or involves structural changes to party walls in attached dwellings.

Most of our Sydney extension clients go the CDC route when the design fits the codes from day one. See our DA vs CDC guide for the full decision logic, or estimate costs before you commit.

Often no — most carports in NSW qualify as exempt development under the Codes SEPP if they meet these limits:

• Maximum floor area 25 sqm (residential zones)
• Maximum height 2.4m (wall height) and 3m overall
• Setbacks: 900mm from side and rear boundaries in most zones
• Behind the building line (not forward of the house)
• Not on heritage-listed land or in certain conservation areas
• Stormwater drained to existing on-site system

If your carport exceeds any of these, you'll need either a CDC (most common) or a DA. Detached garages and larger covered structures almost always need a CDC. Check the NSW Planning Portal's exempt development page for the rule specifics, or send us your site plan and we'll tell you which pathway applies.

Yes — but it requires a DA in almost every NSW council, plus two extra layers of compliance:

1. Planning (DA) — boarding houses are a defined use under the LEP and State Environmental Planning Policy (Housing) 2021. Most councils require DA approval. Zoning must permit boarding houses (R2, R3, R4, B1, B2 — varies by LEP).
2. Building (NCC Class 1b or 3) — a new or converted boarding house must comply with NCC fire safety, accessibility, room size and amenity provisions. Class 1b (small) caps at 12 boarders and 300 sqm floor area; larger developments fall under Class 3 with stricter requirements.
3. Operational — NSW Fair Trading requires boarding house registration, and the Boarding Houses Act 2012 sets ongoing occupancy and reporting obligations.

Because boarding houses trigger the Design and Building Practitioners Act 2020 (Class 3 buildings), drawings must be declared by a Registered Design Practitioner — that's our direct scope. See our boarding house case study for a worked example.

Removing a load-bearing wall is structural work that requires both engineering and approvals — it's not exempt development. The typical sequence:

1. Structural engineer assessment — calculates the replacement beam (steel or LVL) and footing/pier loads
2. Approval pathway — usually a CDC if the work meets Codes SEPP internal alteration standards; DA if external envelope or attached-dwelling party walls are affected
3. Construction Certificate (CC) — certifier issues CC once engineering and plans confirm NCC compliance
4. Licensed builder — NSW work over $5,000 (labour + materials) must be done by a licensed builder under Home Building Act 1989
5. Certificates — engineer inspects beam installation before linings are closed, then certifier issues the Occupation Certificate

Never start this work without engineering — improperly removed load-bearing walls cause sagging floors, cracked ceilings and insurance voidance. We coordinate the designer, engineer and certifier under one fee so you don't manage the hand-offs.