Project-specific solar access analysis for development and planning projects where direct sunlight to rooms, private open space or neighbouring property needs to be reviewed or quantified. The applicable assessment criteria and required outputs are confirmed before instruction.
We confirm the applicable standard before we model a single ray of sunlight
A shadow diagram shows where shadows fall. A solar access assessment goes further: it quantifies exactly how much direct sunlight living areas, private open space and adjoining windows receive — and compares that figure explicitly against the applicable ADG or ResCode threshold. That explicit compliance statement is what planners and certifiers need to approve your DA.
Under the ADG (applied through the Housing SEPP), residential apartment buildings must meet the following at the winter solstice (21 June):
Under ResCode, two key solar access standards apply to most multi-unit and dual-occupancy developments:
Hours of direct sunlight to living areas, private open space and adjoining windows at the applicable reference date — 21 June for NSW, 22 September for VIC. Expressed as a numeric figure.
A clear written statement confirming whether the development meets the applicable threshold — ADG 70% / 2-hour minimum for NSW, ResCode B21 5-hour standard for VIC. Referenced to the specific DCP clause.
Hourly sun-path study at the reference date showing shadow footprints and solar access zones. Existing vs proposed conditions modelled separately, with overlay comparison where required.
Written methodology confirming software, sun-path model, site coordinates, applicable DCP clause, and reference date. Ready for direct inclusion in your Statement of Environmental Effects.
A4/A3 print-ready PDF formatted for DA lodgement, plus DWG and ArchiCAD source files. For apartment projects, a percentage-by-apartment ADG compliance table is included.
One revision round is included within the agreed project scope. Re-issued within 48 hours.
The same issues appear repeatedly in council RFIs. We eliminate all three before lodgement.
Submitting sun-path diagrams without a written statement confirming whether the ADG 70% / 2-hour threshold or ResCode B21 5-hour standard is met is the single most common reason solar access assessments are returned.
NSW requires the winter solstice (21 June). VIC requires the equinox (22 September). Using the wrong date invalidates the entire assessment and triggers a full resubmission.
ADG and ResCode B21 both require impact on adjoining properties to be assessed. Assessments modelling only the proposed building are routinely returned by council assessment officers.
Every deliverable includes a methodology and scope summary identifying the criteria applied. For NSW apartments, a percentage-by-apartment summary against the ADG threshold is included.
We confirm the applicable standard and reference date in writing before modelling starts — 21 June for NSW, 22 September for VIC. Additional seasonal requirements are identified and included in scope before commencing.
Existing and proposed shadow conditions on adjoining habitable room windows and private open space are modelled as part of every assessment — not an optional extra.
Share your drawings, survey, and DA reference. Tell us whether this is an apartment (ADG), dual-occupancy or multi-unit (ResCode).
We confirm the applicable standard, reference date, and any council-specific DCP controls — in writing, before work starts.
Survey-accurate 3D model, solar access study at the confirmed reference date, sun-hour results calculated for the confirmed assessment scope. First draft in 48 hours.
Print-ready PDF, DWG and ArchiCAD source files. For apartment projects, percentage-by-apartment ADG compliance table included.
Every quote is fixed price — not hourly. Invoiced in AUD, no GST applicable.
All prices in AUD, excluding GST. Invoiced from KAS STUDIO DOOEL, Skopje, North Macedonia. Fixed quotes issued within 24 hours of brief received.
A solar access assessment quantifies the amount of direct sunlight received by living areas and private open space at the winter solstice (21 June). Under the ADG (Housing SEPP), at least 70% of apartments must receive 2 hours of direct sunlight between 9am and 3pm.
The ADG requires that at least 70% of apartments receive a minimum of 2 hours of direct sunlight to living areas between 9am and 3pm at the winter solstice (21 June). We produce a percentage-by-apartment compliance table confirming this threshold is met.
Victoria's residential planning provisions were reformed in 2025. Depending on the scale of development, Clause 54, Clause 55 or Clause 57 of the planning scheme now applies, and overshadowing of neighbouring secluded private open space remains a core assessment requirement. The pre-reform standards commonly cited as A14 and B21 have been restructured under the current provisions. We confirm the applicable clause, standard and any local schedule requirements for each project before work starts. Individual councils may impose additional requirements.
No. A shadow diagram shows where shadows fall. A solar access assessment quantifies sunlight hours and produces a written compliance statement against the ADG or ResCode threshold. Many DA submissions require both documents.
Architectural drawings (DWG, PDF or ArchiCAD preferred), a registered survey for true north and boundaries, and the council name or DA reference. For apartment developments, floor plans for all levels and a massing model. IFC and Revit files also accepted.
No. CasStudio is based in Skopje, North Macedonia (KAS STUDIO DOOEL). Invoices are issued in AUD from a non-Australian entity and are not subject to Australian GST. Payment terms NET 14 from invoice date.
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