San Diego’s leading historic preservation group — Save Our Heritage Organisation — took legal action this week in an effort to block the city from softening its historic preservation rules.

SOHO filed an 11-page writ of mandamus demanding the city conduct a comprehensive environmental impact report before changing city historic preservation rules.

The action applies to a package of preservation changes the City Council approved Feb. 24 that includes allowing the council to overrule the city’s Historical Resources Board when the board designates a property historic.

The package also allows developers to take advantage of the city’s controversial Complete Communities incentive in Ocean Beach, as long as a property isn’t the site of a historic cottage.

SOHO says the city improperly relied on previous environmental impact reports analyzing other projects and proposals instead of creating a new one specifically for the preservation rule changes.

SOHO also wants a judge to require the new EIR to analyze simultaneously a second, more robust package of proposed preservation updates that city officials plan to tackle this year.

The second half of the package may include limiting property tax breaks for historic homes and eliminating automatic historical review for buildings when they reach 45 years old.

The two packages together are called “Preservation and Progress.”

The California Environmental Quality Act requires environmental impacts and mitigations for all parts of a project to be studied and approved together as the “whole of the action,” SOHO argues in its writ.

SOHO notes in the writ that the changes approved Feb. 24 were unanimously opposed by the Community Planners Committee, an umbrella group of neighborhood planning groups.

“Historic places are an integral part of our environment and shared city identity,” said Bruce Coons, the nonprofit’s executive director.

Developers and city officials praised the Feb. 24 changes as modest and sensible reforms that would boost the impact of dozens of pro-housing updates and policies the council has approved in recent years.

A spokesperson for City Attorney Heather Ferbert declined to comment, noting that Ferbert doesn’t comment on pending litigation.

For details on the approved and proposed historic preservation changes, visit sandiego.gov/preservationandprogress.