Privacy and sight lines: visual and acoustic privacy in AU residential

TL;DR

If a habitable room window or balcony has a direct sight line to a neighbour’s habitable room or private open space within 9 metres horizontally, you need to fix it: screen, raise the sill to 1.7 m, offset the window, or use fixed obscure glazing below 1.7 m. The rule exists in NSW (ADG), VIC (ResCode A15/B22), and WA (R-Codes 5.4.1), with local DCP overlays that can tighten it further.

The gotcha that stings builders: the certifier flags a first-floor window as a privacy breach after the window order is locked in. Switching to obscure glazing or adding a screen late costs real money and delays. Audit sight lines at design development, not at construction certificate.

What this article is for

Privacy controls show up in planning permits, CDCs, and DA conditions across every state. They protect both parties: the neighbour keeps their POS and bedroom unobserved, and you keep your approval unconditional.

This article covers:

The 9 m sight line rule and how it is measured
Screening device specifications (what counts as a compliant screen)
Balcony privacy screens and their height and opacity requirements
Acoustic separation for Class 2 buildings under NCC Volume 1
How the rules vary by state
The builder gotchas that show up at late stages

If you are working in a specific state, start with this article for the framework, then check the per-state planning scheme article for local overlays.

Visual privacy: the 9 m rule

The core rule, consistent across NSW, VIC, and WA, is this: a habitable room window, balcony, terrace, deck, or patio must be located and designed to avoid direct views into the secluded private open space (POS) or habitable room windows of an existing or approved dwelling within a horizontal distance of 9 metres measured at ground level.

Views are assessed:

Within a 45-degree angle from the plane of the window or the perimeter of the balcony
From a height of 1.7 m above finished floor level (standing eye-level proxy)

That 45-degree cone plus 9 m radius is the zone you need to clear. If any neighbour’s habitable room window or POS falls inside that zone and has a direct sight line, the design fails the privacy test.

“Secluded private open space” typically means the main outdoor area the occupants use for leisure, not a narrow side passage. Councils and consent authorities define it in their DCPs, but it is generally the backyard or courtyard directly associated with the dwelling.

Four ways to achieve compliance:

Achieve the 9 m separation distance (no screen needed).
Install a compliant fixed screening device (see below).
Raise the sill height to at least 1.7 m above finished floor level.
Install fixed obscure glazing below 1.7 m (glass must be permanently obscured, not adhesive film).

Options 3 and 4 only work where the upper portion of the window above 1.7 m does not create a direct view. For a full-height window on a first floor with a neighbour’s pool deck 7 m away, none of the easy fixes work without combining approaches.

Screening device specifications

A compliant screening device must be:

Permanent and fixed: not operable louvres, not retractable, not removable panels.
Maximum 25% open area (VIC ResCode standard; NSW ADG uses similar language): no more than 25% of the screen surface area is open.
Durable and designed to remain permanently in place.

In practice, a fixed louvre screen with 65 mm slats on a 120 mm pitch and a 28 mm gap at the narrowest point sits around 23% open, which passes. Expanded metal with large apertures typically fails. Bamboo screens fail because they are not permanent and fixed.

The screen must extend to at least 1.7 m above finished floor level at the window or balcony edge to block the 1.7 m eye-level sight line. A screen that stops at 1.5 m does not comply.

For windows, the screen is placed at the window reveal or as a fixed louvre outside the glass line. For balconies, the screen typically forms the balcony balustrade extension or a return wall.

Lattice qualifies only if the aperture size is within the 25% open rule. Spaced timber battens typically do not qualify unless the gaps are calculated and meet the threshold.

Balcony privacy screens

Balcony screens have a specific function: preventing a person standing at the balcony edge from looking directly down into a neighbour’s POS or habitable room window below.

Typical requirements across NSW and VIC:

Minimum 1.7 m above finished floor level of the balcony
Minimum 75% solid by area (maximum 25% open), fixed and permanent
Applied to the side or end of the balcony facing the neighbour, not necessarily the full perimeter

In NSW under the Housing SEPP and Codes SEPP, complying development privacy screen conditions require screens on balconies where the balcony edge is less than 3 m from a side or rear boundary and the floor level is more than 1 m above existing ground. Screens must be at least 1.7 m but not more than 2.2 m above finished floor level.

The design intent is to prevent overlooking of the neighbour’s secluded POS from a standing position at the balcony rail. A person seated on the balcony is generally not the test case; standing at the rail is.

Balcony rails that are full glass (frameless glazing) at standard balustrade height (1.0 m to 1.1 m) do not function as privacy screens. If the balcony rail needs to double as a privacy screen, you need 1.7 m of compliant solid or near-solid panel, which means replacing or extending the balustrade design.

Acoustic privacy

For Class 2 buildings (apartments), acoustic separation between sole-occupancy units is a minimum performance requirement under NCC Volume 1 Part F7 (formerly F5 in pre-2022 editions).

Key deemed-to-satisfy figures:

Element	Requirement
Wall between sole-occupancy units	Rw + Ctr ≥ 50
Wall between unit and common corridor, stairway, plant room	Rw ≥ 50
Floor between sole-occupancy units	Rw + Ctr ≥ 50 (airborne); Ln,w ≤ 62 (impact)

These are laboratory ratings. Real-world performance is lower due to flanking paths (structure-borne sound bypassing the rated element). An acoustic engineer specifies the construction method; the builder builds it and is responsible for achieving it.

For Class 1 buildings (detached houses, duplexes), NCC Volume 2 does not mandate inter-tenancy acoustic separation in the same way, but party walls in duplexes must meet NCC Volume 1 Part F7 when the two dwellings are Class 1 on a strata or community title arrangement.

Private open space acoustics are addressed through council DCPs and design standards, not NCC, and typically via site planning rather than rated construction. A pool pump against a boundary fence is a nuisance matter, not an NCC matter.

State variance

The 9 m rule is consistent in the major states, but the instrument it sits in, the measurement details, and the local DCP overlay requirements vary.

State	Instrument	Rule	Key notes
NSW	Apartment Design Guide (for Class 2 via Housing SEPP 2021); Codes SEPP 2008 (for Class 1 CDC)	9 m horizontal separation OR compliant screen	ADG sets separation distances by building height: 9 m for buildings up to 25 m (5-8 storeys), 12 m above 25 m. Council DCPs frequently add tighter requirements.
VIC	VPP Clause 54 Standard A15 (single dwelling); Clause 55 Standard B22 (multiple dwellings)	9 m horizontal, 45-degree cone, measured at 1.7 m above FFL	Screens: max 25% open, permanent, fixed. VC267 (March 2025) amended B22 to exempt bedroom windows in the Townhouse and Low-Rise Code.
WA	R-Codes Volume 1 Section 5.4.1	Cone of vision setback; adjoining features within 7.5 m of site boundary trigger privacy assessment	Setback distance varies by floor level and lot boundary. Compliant screening or sill adjustment required where DTC setbacks cannot be met.
QLD	Local council planning schemes and State Planning Policy	No single statewide 9 m rule; most schemes adopt an equivalent overlooking test	Brisbane City Plan 2014 performance outcomes reference equivalent privacy outcomes; specific DTS distances vary by council.
SA	Planning and Design Code	Performance requirement in residential zones; no fixed 9 m rule at state level	Zone and overlay-specific; assessed as performance criteria against design principles in the Code.

Local DCPs across all states can and do add requirements. Inner-Sydney councils, inner-Melbourne councils, and inner-Perth councils often specify shorter minimum separation distances (6 m in some infill zones), additional screening requirements, and specific balcony screen specifications in their DCP chapters.

What can go wrong

The window order goes in before sight lines are checked. Standard clear-glass double-hung windows are ordered as part of the contract window schedule. At construction certificate stage, the certifier or council planner flags that the first-floor bedroom window overlooks the neighbour’s pool deck at 6.5 m. The options at that point: switch to obscure glazing (special order, cost and lead time), add a fixed external screen (structural fix, engineering, cost), or negotiate a minor design change (if the approval allows it). None of them are free.

Balcony rails specified as full glass at standard height. A 1.05 m frameless glass balustrade is a legal balustrade. It is not a privacy screen. If the balcony faces a neighbour’s habitable windows or POS within 9 m, the certifier will condition a privacy screen on top, or the DA will condition it. Finding this out after the balustrade is installed means either extending it (complex fix to an already-certified balustrade system) or arguing the point with the consent authority.

Obscure glazing specified as window film. Adhesive frosted film does not satisfy the fixed obscure glazing requirement in VIC and is not accepted in most NSW councils either. The glazing must be factory-etched, sandblasted, or use a patterned obscure glass unit. If you spec film and the certifier rejects it at inspection, you replace the glazed unit.

Screening device is operable. Adjustable louvre blades look like they screen; they do not comply as a privacy device because they can be opened. Fixed blade louvres at the correct pitch and gap pass; operable ones do not.

DCP requires tighter than 9 m. Some inner-urban DCPs (particularly in Sydney and Melbourne) set 6 m minimum separation in higher-density zones, or set specific screen heights above ADG/ResCode minimums. Reading only the state instrument and not the local DCP misses these. Pull the local DCP chapter for privacy/amenity before finalising window placement.

The planning instrument hierarchy explains where ADG, ResCode, and R-Codes sit in each state’s system and which instrument prevails when they conflict.
DCPs is where the local overlay requirements that tighten the 9 m rule are found. Pull the DCP privacy chapter for every project.
Setbacks and solar access and overshadowing cover the related controls that often appear in the same DCP chapter as privacy.
NSW planning scheme structure and VIC planning scheme structure provide the per-state context for how ADG and ResCode are applied.
Housing SEPP 2021 NSW blanket override covers the SEPP that brings the ADG into effect for Class 2 development statewide and its interaction with council DCPs.

References

NSW Apartment Design Guide, Part 4 (Designing the Building), via planning.nsw.gov.au (verified 2026-05-23).
Victoria Planning Provisions, Clause 54 Standard A15 and Clause 55 Standard B22 (overlooking), via Planning Practice Note 27 (verified 2026-05-23).
WA Residential Design Codes Volume 1 (State Planning Policy 7.3), Section 5.4.1 Visual Privacy, via wa.gov.au planning (verified 2026-05-23).
NCC 2022 Volume 1 Part F7 Sound Transmission and Insulation, via ncc.abcb.gov.au (verified 2026-05-23).
SEPP (Exempt and Complying Development Codes) 2008 Regs 3B.42, 3C.18, 3D.37 (privacy screens), via austlii.edu.au (verified 2026-05-23).

TL;DR

What this article is for

Visual privacy: the 9 m rule

Screening device specifications

Balcony privacy screens

Acoustic privacy

State variance

What can go wrong

How to use this with related articles

References

Related

See also

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