Inner-city homes overlooking Kings Park or backing on to nature strips would be treated the same as semi-rural blocks under proposed new bushfire planning policy and guidelines.
Residents building on such sites could face development restrictions and be slugged thousands to equip their properties with anti- bushfire measures.
More than 130 properties bordering Kings Park - as well as development on Heirisson Island - could be affected, a report has warned.
The State Government's draft planning policy and guidelines would require new homes in areas either identified as bushfire-prone or within 100m of at least one hectare of bush to have bushfire hazard assessments.
Depending on what risk grading they received, building requirements, such as ember screens over evaporative air-conditioners and low-combustible building materials, could apply.
The Urban Development Institute of Australia's WA division and the City of Perth were concerned the policy did not differentiate between urban areas, where the risk of property damage from bushfire was minimal, and places in the Perth Hills and south of Perth at greater risk.
UDIA WA chief executive Debra Goostrey said the capacity to fight bushfires in urban environments was vastly different to more remote areas.
A report to the City of Perth's planning committee this week identified 137 properties around Kings Park that would be affected under the proposed policy, excluding those that fall into the City of Subiaco's boundary.
Perth Lord Mayor Lisa Scaffidi said the city was studying the implications of the draft policy.
Planning Minister John Day said he was aware of the concerns and feedback would be considered for the final policy.