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UK & Australia · Compliance Documentation

Daylight, Sunlight
& Solar Access Analysis.

Daylight, sunlight and solar access assessments for UK and Australian planning submissions. Assessment methodology and scope are confirmed against the applicable framework — BR 209 (2022) for UK projects, ADG, Housing SEPP or ResCode for Australian projects — before instruction.

Choose Your Market Get a Quote
UK — BRE 209 / VSC / APSH / NSL NSW — Housing SEPP / ADG VIC — ResCode A14 / B21 18+ Years Experience
Choose Your Market

Daylight and sunlight analysis for UK and Australian submissions

Different markets use different standards. Select the one that applies to your project.

United Kingdom
Daylight & Sunlight Assessment
BRE 209 — for UK planning applications
VSC — Vertical Sky Component · 27% threshold · <20% reduction rule
APSH — Annual Probable Sunlight Hours · 25% annual · 5% winter minimum
NSL — No Sky Line analysis · 20% loss threshold · working plane
Shadow diagrams at equinox and winter solstice
Written BRE 209 methodology statement included
From £280 · householder applications · full BRE 209 assessments join the line late August 2026
UK Daylight & Sunlight Assessment →
Australia — NSW & VIC
Solar Access & Daylight Assessment
ADG / ResCode — for Australian DA submissions
NSW — Housing SEPP / ADG · 70% of apartments · 2h at winter solstice · 21 June
VIC — Current Victorian planning provisions · Overshadowing assessed per applicable clause
VIC — ResCode Standard A14 · habitable room windows · equinox reference
Explicit ADG / ResCode compliance statement included
Percentage-by-apartment compliance table for NSW apartments
From AUD 1,800 · dual occupancy / small multi-unit · AUD 3,500+ apartment development
AU Solar Access Assessment →
Methodologies

What we measure and why it matters

Each metric quantifies a different aspect of daylight and sunlight access. We apply the correct methodology for your market and planning authority.

VSC
Vertical Sky Component
Measures the proportion of sky visible from a window. A VSC of 27% or above indicates adequate skylight. Reductions of more than 20% of the former value are considered potentially harmful.
UK — BRE 209
APSH
Annual Probable Sunlight Hours
Measures hours of direct sunlight reaching a window over the year. BRE 209 recommends at least 25% of APSH annually, including 5% in winter months (September to March).
UK — BRE 209
NSL
No Sky Line
Divides the working plane of a room into areas that can and cannot receive direct skylight. If the area receiving skylight falls below 0.8 times its former value, occupants will notice the change.
UK — BRE 209
ADG
Apartment Design Guide
NSW standard applied under the Housing SEPP. Requires 70% of apartments to receive at least 2 hours of direct sunlight to living areas between 9am and 3pm at the winter solstice (21 June).
NSW — Housing SEPP
B21
Current Victorian Provisions
Victoria's overshadowing standard for private open space. Proposed development must allow adjoining properties to receive at least 5 hours of sunlight to secluded POS at the equinox (22 September), 9am–3pm.
VIC — ResCode
A14
ResCode Standard A14
Victoria's solar access standard for habitable room windows of adjoining dwellings. Assessed at the equinox (22 September) between 9am and 3pm. Applied alongside B21 for most multi-unit developments.
VIC — ResCode
Why It Matters

Why daylight and sunlight documentation is AI-resistant

Compliance documentation cannot be generated by AI or automated tools alone. It requires professional accountability, verified geometry and a clear methodology statement.

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Survey-Accurate Geometry Required
Every assessment starts from your registered survey and architectural drawings. True north, site boundaries and neighbouring property footprints are verified before a single shadow is modelled. Generic or approximated geometry is not accepted by planning authorities.
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Methodology Statement
Every deliverable includes a written methodology statement confirming the software, sun-path model, site coordinates, applicable standard and reference dates. This statement is what makes the assessment verifiable — and what planning officers check first.
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Professional Accountability
Daylight and sunlight assessments carry professional accountability. If a council challenges the results, we review the RFI, update the analysis and re-issue. One revision round is included in every assessment at no extra charge.
Also Need Shadow Diagrams?

Shadow diagrams and daylight assessments are different documents

Many planning applications require both. Shadow diagrams show overshadowing extent — daylight and solar access assessments quantify how much light reaches rooms and open spaces. We deliver both.

UK + Australia
Shadow Diagrams
Overshadowing plans and sun path studies for planning and DA submissions. From £280 / AUD 400.
Australia
Shadow Diagrams Australia
Overshadowing assessments for NSW, VIC, QLD and WA. From AUD 400.
Get a Quote
Fixed-price quote within 24 hours.

Tell us your market (UK or AU), project type and planning authority. We'll confirm the applicable standard and provide a fixed quote within one business day.

AU Solar Access Assessment UK Daylight & Sunlight Assessment

Or email directly: info@casstudio.com