Case Study 2: Staircase Lighting Design for Council Reservoir Gardens
Service: Public Lighting Design | Standard: AS/NZS 1158 (Category PE2) | JG Consulting
## The Brief
Anonymous Reservoir Gardens is a heritage public space on Anonymous Street, with a garden staircase connecting the upper terrace to the lower lawn area. The existing lighting on the staircase and surrounding structure no longer met current safety standards, and council required any upgrade to be formally compliant with AS/NZS 1158 before it could be approved.
JG Consulting was engaged to design a lighting upgrade that would:
- Bring the staircase and surrounding walkway up to the council-agreed AS/NZS 1158 Category PE2 lighting standard
- Improve safety and visibility on the stairs at night without over-lighting the heritage garden setting
- Make the best use of the existing structure and pole infrastructure already on site, rather than requiring extensive new civil works
## The Design Solution
Working from the CAD survey and site conditions, we developed a two-part lighting solution that layers light across the staircase from top to bottom:
1. Additional light on the existing structure
A wall-mounted luminaire (BEGA W1, 40W) was added to the top of the existing garden structure at a 5m mounting height. This provides even, downward wash lighting over the upper landing and the top of the stairs, using a fixture that sits discreetly against the existing architecture rather than introducing new poles or brackets.
2. A second luminaire on the existing pole, mounted lower
The existing pole (P2) near the staircase already carried one luminaire serving the upper area. Rather than installing a new pole for the lower stairs, we specified a second matching luminaire (Radflair Pro, 57W) mounted lower on the same pole with a 3m arm. This "stacked" arrangement means one pole now lights both the top and bottom sections of the staircase, with the lower fixture picking up where the upper light's throw tapers off — closing the gap in coverage down to the lower landing.
This approach avoided extra excavation, new footings, or additional power runs, keeping the upgrade cost-effective while still achieving full compliance.
## How the Works Were Carried Out
1. Site and CAD review – existing structure, pole locations, and services (manholes/cabling) were mapped from the council-supplied CAD file.
2. Photometric modelling – each proposed luminaire was modelled using manufacturer IES photometric files to calculate horizontal and vertical illuminance across every step and landing.
3. Compliance check against AS/NZS 1158 – results were tested against the Category PE2 requirements for average illuminance, minimum illuminance, and uniformity (the ratio between the brightest and dimmest points), to make sure light spreads evenly down the stairs with no dark steps.
4. Documentation for council approval – a luminaire schedule, calculation summary, and 3D render of the lit staircase were prepared and issued for client and council review.
5. Installation – the new BEGA wall light was fixed to the top of the existing structure, and the second Radflair luminaire was installed on the existing pole using a 3m mounting arm, tied back into the existing circuit.
## The Results
The final design achieved compliant, even lighting across all three flights of the staircase:
| Measure | Result |
|---|---|
| Average horizontal illuminance | 21 lx |
| Point horizontal illuminance | 7 lx |
| Horizontal uniformity (U2) | 8 |
| Point vertical illuminance | 7 lx |
Illuminance across the individual stair flights averaged between 33–36 lx horizontally, with vertical (step-face) lighting consistently above the minimum needed for safe foot placement at night — all achieved with just two luminaire types and no new poles.
## Why It Matters
This project shows how a lighting upgrade doesn't always mean starting from scratch. By re-using the existing pole and structure and carefully modelling where light was actually needed, we delivered a fully AS/NZS 1158 PE2-compliant staircase lighting solution that improves safety for the public, respects the heritage character of the gardens, and kept installation works to a minimum.
If you need a staircase, walkway, or public area lighting design that meets AS/NZS 1158 and council requirements, get in touch with JG Consulting — we handle the photometric calculations, compliance documentation, and design drawings from concept through to council approval.