Midland infill - what happens now?

I recently wrote a blog about the role of infill development in the established parts of Australian cities.  The example of Laverton, in Melbourne's western suburbs was used.  It showed that despite the incremental nature of infill development, it plays an important role in adding to the dwelling stock.  However the supply of land available for infill is constrained, both by the individual decisions of home owners and the planning scheme.  What happens when a suburb has been infilled?  This blog will consider the example of Midland, an established suburb in Perth's north east.

Midland

The suburb of Midland is located in the City of Swan around 18km north east of the Perth CBD.  It has the advantage of good public transport links into the city via train and the town centre is located at the junction of two major highways.  The area around the railway station developed from the early 20th century but suburban development spread northward in the post war era.  The population of Midland was 13,133 in 2016, an increase of 11% on the 2011 figure of 11,858.  This is a more modest growth rate than the City as a whole.  

Infill study area

To examine the impact of infill over time, a study area was created (see map below).  This is bounded by Morrison Road in the south, the Great Northern Highway in the west, Spring Avenue in the north, and Lloyd Street in the east.  The corner of Great Northern Highway and Morrison Road is approximately 1km from the Midland train station (walking or driving).

The grid street pattern dominates, deviating from this pattern only around Spring Avenue.  By the 1950s suburban development was well advanced with only market gardens remaining.  There are 494 blocks of land but a small number are occupied by commerical premises or non-private dwellings such as aged care facilities.  These are not included in the analysis, leaving 481 residential blocks in the study area.

The impact of infill development in Midland

An analysis of infill development in the study area was undertaken by comparing aerial photography in Google Earth over five time periods between 2008 and 2017.  Changes in dwellings were observed and numbers were verified using the eLodge facility on the City of Swan website.  

In 2008 there were 877 dwellings in the study area, and this had increased to 1,199 in 2017.  This represents an increase of 322 dwellings, or 37%, over the 11 years.  Notably, this time period covers a period of very rapid growth in Perth during the mining boom years.  However, most of the dwelling change has occurred since 2014, which covers the post-mining boom years and the corresponding decline in population growth and dwelling construction.  This may be explained by planning lag, in that the developments were approved some years before their completion.  

The number of dwellings on each block in 2008 and 2017 is shown in the table below.  Clearly, the number of blocks with one dwelling decreased over the 11 years, whereas blocks with three or more dwellings increased in number.  This is typical of the way infill development occurs in established suburbs - the older house on a larger block is demolished and replaced with villa units. 

There was a notable increase in the number of blocks with eight or more dwellings.  This is driven by a number of factors, including the large size of the original blocks (some are quite deep), the age of the dwellings, some site amalgamation and strategic planning policies encouraging infill development in exisiting suburbs, particularly those near train stations.  Elsewhere in Midland the commercial core and former railway workshops continue to undergo redevelopment, encouraging other types of development in the suburb.  

There was no clear spatial pattern with regards to infill.  Theoretically, it would be expected that larger infill developments would be located closer to public transport, but this was not necessarily the case.  The largest blocks are located in the northern part of the study area, and as such these can accommodate larger developments.  An example is the 40 unit apartment building on the corner of the Great Northern Highway and Spring Avenue completed in 2017.

How much more infill can Midland accommodate?

It's important to note that infill development is subject to the decisions of individual property owners and is incremental in nature.  Although there are some parts of inner Perth that have experienced very high rates of infill development, it shouldn't be expected that all residential blocks will be redeveloped in the future.  

The table above shows that in 2017, there were 27 vacant blocks and 255 blocks with a single dwelling in the study area.  However, not all of these may be suitable for redevelopment.  The most obvious example is small blocks, but there may also be blocks where the dwelling was built more recently, or which have stronger planning controls such as a heritage overlay.  If recently developed parcels and smaller blocks are excluded, then there is potential for another 230 blocks to be redeveloped in the study area.   

Summary

Midland is located around 18km from the Perth CBD.  It has a long history of suburban development due to its strategic transport links and location in the Perth metropolitan area.  In recent years there has been a considerable amount of infill throughout the suburb.  The study area presented here, encompassing an area off the Great Northern Highway, recorded a 37% increase in the number of dwellings between 2008 and 2017.  Single homes on larger blocks are slowly making way for villa units, townhouses and even apartments.  Infill development, though incremental, does add to the dwelling stock in established parts of Australian cities and can't be discounted as an important part of the dwelling supply.