Before either dwelling in a dual occupancy can be occupied, it must be covered by a Certificate of Occupancy and Use for its intended residential use. For building work requiring a certifier, the certifier must first issue the required Certificate of Completion. ACT Planning also notes that completion includes relevant electrical, gasfitting and plumbing work.

It is unlawful to occupy or use a building, or part of a building, without the required Certificate of Occupancy and Use.

Reference: Act Planning: Completion Certificates – https://www.planning.act.gov.au/community/build-or-renovate/upon-completion/completion-certificates

Yes, potentially. One dwelling may be occupied while the other is still under construction if the completed dwelling is covered by an appropriate Certificate of Occupancy and Use.

The Building Act 2004 allows a certificate to be issued for a completed part of a building where that part satisfies the applicable requirements. The remaining uncertified part cannot be occupied.

This means it is not automatic that one dwelling can be occupied simply because it is finished—the required occupancy certification must first be obtained.

Reference: Building Act 2004 (2004-11) – Sections 69(3), Certificates of occupancy & 76, Occupation and use of buildings – https://www.legislation.act.gov.au/View/a/2004-11/current/html/2004-11.html

Not necessarily for every dual occupancy. The current Residential Zones Technical Specifications 2026 does not impose a general requirement that every dual-occupancy site must provide a turning area so vehicles can always leave in a forward direction. The need for vehicle manoeuvring depends on the applicable parking, access and site-design requirements.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303) – Car Parking and Vehicle Access provisions – https://www.legislation.act.gov.au/View/ni/2026-303/current/PDF/2026-303.PDF

Certain building elements can extend into the required setback without being treated in the same way as the main building. These include:

• eaves or roof overhangs up to 600 mm;
• fascias, gutters, downpipes, light fittings and sun blinds;
• landings, steps or ramps that are no more than 1 m above finished ground level; and
• for side and rear setbacks only, certain additional elements such as rainwater tanks, clotheslines, hot water systems, chimneys, heating or cooling appliances, utility meters, unroofed pergolas, solar inverters and batteries.

Balconies are not included in the listed allowable setback encroachments, so they should not automatically be assumed to be permitted within the required setback.

Reference: Residential Zones Technical Specifications 2026 (NI2026-303), 14.5 Allowable setback encroachments – https://www.legislation.act.gov.au/View/ni/2026-303/current/PDF/2026-303.PDF

Yes, generally. Site coverage is based on the area of the site occupied by buildings and roofed structures. This means structures such as garages and carports generally contribute to site coverage.

A covered outdoor area may also contribute to site coverage where it forms part of the roofed/built development. By contrast, unroofed areas should not automatically be treated as site coverage merely because they are paved or used as outdoor space.

For a dual occupancy, all relevant roofed structures should therefore be considered when calculating the total site coverage against the applicable limit.

Reference: Residential Zones Technical Specifications 2026 (NI2026-303) – Site Coverage provisions – https://www.planning.act.gov.au/__data/assets/pdf_file/0020/3092411/ACT-Missing-Middle-Housing-Design-Guide.pdf

Not necessarily. Upper-floor windows do not automatically need privacy screens. The design must appropriately address privacy and overlooking under the applicable ACT planning provisions and design guidance.

The Missing Middle Housing Design Guide recommends designing private spaces and openings to minimise overlooking and identifies measures such as building and window positioning, landscaping, louvres, screens, battens and other architectural treatments where additional privacy is needed.

A privacy screen is therefore one possible design solution, rather than an automatic requirement for every upper-floor window.

Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 16 – https://www.legislation.act.gov.au/View/ni/2026-303/current/PDF/2026-303.PDF & Missing Middle Housing Design Guide 2026,5.2C Privacy and Outlook – https://www.planning.act.gov.au/__data/assets/pdf_file/0020/3092411/ACT-Missing-Middle-Housing-Design-Guide.pdf