Matthew Bai
Public transport can be an effective means for the movement of large numbers of people, with many global cities already having successful public transportation networks. Auckland is currently undertaking work to improve and expand its own network of rapid transit in an attempt to transition away from a car oriented urban environment.
I often hear the terms “the corridor is zoned for high density” used as part of the supporting evidence for a particular piece of public transport infrastructure such as Light Rail down Dominion Road. This is great, infrastructure is often expensive and can only be justified if the underlying zoning along its route provides for sufficiently high intensity land use. In addition, strong evidence is emerging that significantly higher levels of intensification is beginning to occur along public transit corridors including Great North Road.
However, there is often a misunderstanding (both by policy-makers, as well as the public), about the true nature of zoning, and what practical implications these decisions bring about.
As this is a complex and structural matter, I intend for this to be an ongoing series- with each installment focusing on a particular project or geographic location. Instead of taking a “theoretical” approach, I will take a more “practical” and at times more technical viewpoint when addressing the issues at hand.
Ultimately, the constituent parts which make up a city are its individual land parcels, and these are what have the greatest impact on the development capacity along any given transportation route.
Today, we will take a look at a stretch of Auckland’s Dominion Road, and analyze our findings in relation to how much development is realistically achievable.
The idea for using Light Rail on Dominion Road has existed for a while now, first being raised as a solution to bus congestion in the CBD. It is now set to be continued from Mount Roskill to Auckland Airport. The project is currently in the procurement stage, with detailed investigations taking place, and due diligence being conducted.
With the cost of the Dominion Road section alone likely to be over $1 Billion, it is important we maximize the benefits of this investment through the zoning.
The sample map area has been selected as it provides a representative snapshot of zoning and subdivision patterns along the route.
Map depicting Dominion Road, showing zoning and cadastral pattern:
(The map is sourced from Geomaps, a free mapping program created by Auckland Council, available here: https://geomapspublic.aucklandcouncil.govt.nz/viewer/index.html)
We will focus on the 30 Ha contained within the circle.
As the map shows, the area contains a number of zones and zone interfaces, including Local Centre Zone (LCZ), Mixed Use Zone (MUZ), Terraced Housing & Apartment Buildings (THAB), Single House Zone (SHZ), and limited Mixed Housing Urban (MHU). Some sites are subject to a 13 meter HVC, while others are subject to heritage protection. There are no volcanic viewshafts present.
There is no vacant land within this area, meaning for any development to take place, demolition of existing structures is necessary.
In terms of development potential, I consider the case study area to be constrained, due to the substantial presence of SHZ, and HVC below that of the default height limits for each respective zone. From a development perspective, the SHZ can effectively be considered “unusable” (for all practical purposes), due to severe limitations relating to minimum subdivision size and an 8 meter height limit.
This leaves us with the remaining zones, which theoretically allow intensive development. While some sites have a low HVC, there are still Mixed-Use zoned sites which are not subject to any special restrictions. Unfortunately, most of these sites are very narrow, with some adjoining the SHZ towards the rear. The implications of this are, that for most development to occur, an investor would need to amalgamate multiple consecutive sites. Current examples indicate developers tend to simply under-develop a site, as opposed to expanding their landholdings in order to fully utilize the potential.
Another issue I’ve identified, relates to the extend of “Mixed-Use”, or “Local Centre” zoned land along this corridor. As the diagram below indicates, MUZ land only extends one parcel “deep”, before transitioning abruptly to SHZ.
In a high density urban environment, people are typically willing to walk 5-10 minutes to the nearest bus stop, or in this case, a light rail station. We refer to this as a “pedestrian catchment”. It is within this catchment that high density development should be enabled, due to the close proximity to public transport options, and high usage which can be expected.
However, the current zoning (regardless of cadastral pattern related limitations), does not recognize these issues.
The following are a list of Zone Interfaces present:
THAB adjoining SHZ
MUZ adjoining SHZ
LCZ adjoining SHZ
MHU adjoining SHZ
MHU adjoining THAB
MHU adjoining MUZ
MUZ adjoining THAB
LCZ adjoining THAB
For those unfamiliar with Auckland Unitary Plan zones and terminology, I’ve included a key below:
SHZ= Single House Zone
THAB =Terrace Housing and Apartment Building Zone
MHU = Mixed Housing Urban Zone
MUZ = Mixed Use Zone
MHS =Mixed Housing Suburban Zone
LCZ = Local Center Zone
HVC = Height Variation Control
The difficulty of having multiple zone interfaces, is that each brings about its own set of recession plane rules, and these often severely limit the development potential of any affected land, (especially when dealing with smaller, or narrow sites as determined by the second order subdivision). As a simple example, when any “center” zone borders for THAB zone, the following recession plane is triggered:
Example of zone interface between “Center/Business” zones, and residential THAB zone, triggering 60 degree recession plane at 8 meters.
When working with the issue of land use planning/zoning and transportation infrastructure integration, there are always conflicting interests involved. In an established city like Auckland, where the built environment has long been defined, it can be difficult to accommodate the desires of all parties.
Infrastructure requires development to support it, and development inevitably brings about change. Comment down below what you think about this topic, and any solutions or suggestions you might have.