Tens of thousands more Western Australian home owners will be able to subdivide their properties under a major shake-up of planning rules aimed at boosting housing supply as Perth continues to fall short of its infill targets.Housing Minister John Carey said an overhaul of residential design codes, or R-Codes, would allow about 50,000 more residential properties to be subdivided.It would allow residential blocks of 700 square metres to be subdivided for blocks zoned 'R20' and below, which is a low-density classification that applies to the most common residential properties across Perth's metropolitan area.That is a decrease from the current minimum block size of 900sqm. Swathes of land in suburban Perth, like these blocks sized around 700sqm, could be rezoned. (Supplied: Nearmap)Mr Carey described the proposed reforms as a "game changer" that would unlock more land for housing and streamline processes to make it easier to build homes. He said it was the biggest change to R-Codes in three decades."The proposed changes enable tens of thousands of existing properties to be subdivided that couldn't previously, providing more opportunities for housing in existing suburbs," he said.Mr Carey also released a so-called "health check" on the government's plan to provide adequate housing to accommodate a population of 3.5 million across the Perth and Peel regions by 2050.It acknowledged Perth's annual urban infill rate continued to fall below the 47 per cent target.Infill projects, like this one in Perth's inner north, are still not enough to prop up the city's targets. (Supplied: Nearmap)But the data showed there had at least been an increase from 34 per cent in 2023 to 39 per cent in 2024.Cutting red tapeThe suite of changes is also aimed at cutting bureaucracy so that more simple residential projects, such as single houses, renovations, patios and carports, no longer need planning approval. They would also aim to halve the approval time for single dwellings from 60 to 30 days. Other changes under consideration include:Removing minimum parking requirements for apartments and granny flats;Increasing density from two storeys to three storeys in R40 zones;Reviewing building heights in medium and high-density areas. The move has been backed by the Property Council of WA, the Planning Institute of Australia and the Housing Industry Association. Cameron Leckey from the WA branch of the Planning Institute of Australia said he encouraged any move to increase density in areas where infrastructure already exists.Cameron Lecky and the Planning Institute of Australia's WA branch are backing the changes. (ABC News: Courtney Withers)"We are thrilled to see [R-codes] simplified to free up planners to do what we do best, which is to think strategically and plan for the state rather than get bogged down in regulatory matters," he said. Mr Carey said the proposed changes would be released for public consultation later this year, with implementation expected in July 2027.