Auckland Council asked LDP to enhance St Patrick’s Square (the Square) and the Cathedral façade at night time and identify it as one of Auckland’s iconic buildings and premier public spaces.
Auckland Council initially provided the following brief to LDP:
- To enhance St Patrick’s Square (the Square) and the Cathedral façade at night time and identify it as one of Auckland’s iconic buildings and premier public spaces.
- To provide a place within the Square for people to reflect and enjoy a peaceful experience and comply with CPTED principles.
- To integrate with the landscape architecture and features within the square, e.g. feature tree, water feature, ’Steps’ sculpture, pedestrian pathway linking upper and lower Federal Street.
- To provide visual guidance to pedestrians, whilst entering and also when in the Square.
- Consider sustainable practices in equipment selection.
- To adhere to Heritage Planning and the Cathedral committee requirements with regard to placement and effects of luminaires.
The Cathedral and Square are listed under Auckland’s Heritage Plan. LDP therefore had to ensure full compliance with regard to location and appearance of the luminaires and effects.
The Square is overlooked by a high rise residential building and lighting had to be strictly controlled to limit all off-site effects, particularly glare.
During the installation process for the Cathedral façade lighting it was discovered that the foundations as installed were not the same as that shown on the drawings provided to LDP. This resulted in the perimeter in-ground luminaires for the façade lighting having to be reviewed as there was insufficient depth to accommodate the luminaires. As the luminaires had already been purchased, a raised concrete plinth was designed to house the luminaires in the correct location with respect to the building’s features and maintain the lighting intent. Unfortunately this resulted in the lighting effect providing a scallop appearance just above ground level instead of an even wash from ground level upwards.
There were areas within the grounds where lights were not allowed. This was to prevent any potential disturbance of historic burial remains.
The locations, of the in-ground lights for the feature tree, were restricted in order to prevent damage to the tree roots.
Sections of the north east and south west corners of the site are joint use for vehicles and pedestrians, so the locations of luminaires and/or poles were restricted.
At the time of the design, the available options with LEDs were limited to a relatively small range of fittings and most with low light output were designed for visual guidance purposes only. This was an important limitation as the functional lighting required a higher light output to achieve the requested illuminance level.
LDP investigated a number of options to light the Square and Cathedral. These investigations examined a variety of luminaires, lamp technologies, power supply alternatives, sustainable elements and feature lighting.
This resulted in a decision by the project representatives to proceed with a combination of metal halide discharge luminaires for the key pedestrian lighting, large features and sustainable LED luminaires for lighting the water feature. (At the time of the design the available LED technology was not sufficient for high power lighting solutions, e.g. area lighting and large facades).
Due to a number of factors the installation work was undertaken in two stages. Stage 1 for the Square and Stage 2 for the Cathedral façade.
In keeping with CPTED (Crime Prevention Through Environmental Design) principles, the lighting selected to provide the illumination of the main car parking/paved pathway areas of the Square, comprised cool white light with good colour rendering and good visual comfort (low glare).
This meant keeping the structures as close to human scale as practical, while having sufficient height to provide an economical means of achieving the Cat P7 design category for the main pedestrian pathway and Cat P7 horizontal for the Cathedral entrance area. This provided clear visual guidance and safety for pedestrians using the pathway and Cathedral entrance.
Visually appealing elements were incorporated into the Square features in the form of LED saturated colour and cool and warm colour temperature metal halide fixtures.
Blue LED fixtures were incorporated into the water feature to enhance the feature and provide a visually relaxing appearance.
The feature tree was highlighted in warm white light to add depth and dimension to the Square and achieve a pleasant place for patrons to relax.
Luminaires placed under the seats provided a wash of light on the paving with no glare to patrons.
Framed projector lights illuminated the exterior of the Cathedral’s stained glass windows using high colour rendering lamps and cool white light. This featured the stained glass when viewed from inside during church services.
The final lighting concept assured a cohesive approach linking the various sections and elements of the Square and Cathedral whilst providing for safety and security. We also kept the number of lighting poles to an absolute minimum to allow as much free space as possible for the public.
To demonstrate the effects proposed for the Cathedral façade, LDP undertook a computer generated rendering followed by a temporary mock-up on site (with help from Kenderdine PLS for equipment and temporary supplies). This enabled Heritage Planning and Cathedral representatives to visualise what we were proposing and provide approval for the LDP concept.
Working with the landscape architect, heritage planning and cathedral representatives we ensured that all luminaires were concealed wherever possible and integrated into the various structures and features as much as possible. The intention was for the emphasis to be for the featured elements and structures to be seen, i.e. see the effects of the lighting rather than the luminaires.
Working with the Cathedral architect and heritage planning we were able to provide the lighting for the cathedral façade with very few luminaires being visible. Those that were visible were painted or finished to blend with the façade.
We wanted to provide a lighting solution that projected the space as a liveable and inviting place to be and not just another public space based purely on satisfying minimum lux levels.
Lighting has been designed to tactfully guide those patrons “passing through” the Square and to provide a pleasant and relaxing place for patrons who wish to linger, meet and socialise.
All lighting for the Square and Cathedral is controlled and integrated to provide a coordinated lighting approach and that can be over-ridden by the cathedral for special services as required.
The selected luminaire for the pedestrian area lighting was the Schreder, Puntila 70 watt metal halide version with a soft backlight throw within the diffuser and neutral cool colour temperature. The mounting height for the luminaires is 6m.
Using this luminaire enabled the minimum number of lights and poles for pedestrian areas whilst adding a feature and visual guidance.
The neutral white light provided a clear differentiation between the warm temperature and saturated colour lighting used for the various features.
Coloured lighting was used to accentuate and identify the water feature.
Warm white was used to accentuate the feature tree and the paved/grassed areas within the Square..
As well as the pedestrian circulation areas cool white was used for the sculpture to differentiate from the low warm temperature and low level lighting of the quiet areas of the Square.
A combination of warm and cool colour temperature lamps for the façade lighting enhanced the building’s features and provided a 3 dimensional appearance.
The design has met all of the design criteria for a Cat P7 in the designated pedestrian circulation and through traffic areas.
The lighting in the remaining public areas provides a pleasant and relaxing ambience and excellent visual guidance thereby meeting the design brief.
Glare is the most important element to consider for Visual Comfort. The luminaires used for the Square and façade have all been selected and located to minimise glare, i.e. from normal viewing directions the effects of the light are seen rather than the light sources. All pole mounted lights project the light below the horizontal plane.
The pedestrian area luminaires use white light with a neutral colour temperature of 4300K and a CRI of 90. With the placement and aiming of the luminaires combined with the contrasting colours, the resulting effect is indeed visually very comfortable, as proven by the positive feedback and support from the public and Cathedral representatives.
The only high wattage metal halide lamps used were for the main spire of the Cathedral. Other metal halide lamps used comprised of 70 watt, 35 watt and 20 watt ratings. All other luminaires contained low energy LED sources resulting in a fraction of the energy consumption, compared to halogen and metal halide sources which were predominantly used for these applications at the time of our design for the Square and Cathedral.
The installation utilises the most efficient product available on the market at the time with the equipment features and colour temperature chosen.
The lighting is controlled to automatically switch off non-essential lighting outside of the designated ‘peak’ use times.
Operation and Maintenance
The system operation is fully automatic through a lighting control system controlled from within the Square. This system can also be manually over-ridden for special services and controlled from within the Cathedral.
The system is relatively low maintenance. The LED lamps, electronics, and columns are all estimated to have a service life in the order of 15 years. The only components that should require replacement are the metal halide discharge lamps, which have a nominal 3 year life.
Dark Sky Considerations
The main pedestrian area luminaires have been installed with zero upward tilt.
All other luminaires have been located and/or aimed to minimise upward wasted light output and of low wattage. As a result, the optics controls the light to minimise glare to observers beyond the site.
As such, the potential sky glow has been minimised as much as possible and the night sky preserved.
The lighting works was part of the square’s $10m refurbishment project. The lighting included approximately 175 in ground, facade, spot and water feature lighting to the historic St Patrick’s Cathedral Grounds. An excellent outcome to an Auckland Council’s City transformation was achieved.