To see an interactive page about the proposals and weigh in on the rule changes, visit arcg.is/2BO3KNd .

Downtown Spokane is vibrating with development.

The rumble of jackhammers at The M. The growl of earth movers in Riverfront Park. The hum of pavers around road construction. Look down any street, you’re bound to see something happening.

But two blocks, both largely composed of surface parking, are conspicuous in their lack of activity. Situated along Spokane Falls Boulevard, and between Howard and Washington, the blocks are the subject of new rules being discussed at Spokane City Hall that would lift building height restrictions on properties fronting Riverfront Park.

Current rules, in place since 2009, limit building heights along the south side of Spokane Falls Boulevard to 100 feet, after which stories must be setback 15 feet, creating a tiered, staircase-like form.

This rendering shows the largest building allowed under current city rules, where each story above 100 feet must be set back 15 feet, creating a tiered, staircase structure. Shadows appear as they would May 1. (City of Spokane)

The rules were created 10 years ago due to a mandate in the city’s Downtown Plan, which says that “the Spokane community expressed a strong desire to maintain maximum exposure to sunlight in significant public open spaces, such as Riverfront Park, by promoting buildings designed to reduce shadows.”

But following the October release of a report on building heights by a group of 15 members from the city, plan commission, neighborhoods and development companies, new rules are under consideration to lift such height restrictions while limiting the uses of the buildings to residences or hotel rooms.

The largest building allowed under the proposed rules would limit buildings to a 100-foot-tall base. Above that, floors would be kept to 18,750 square feet or less in an attempt to allow more sunlight through, even though tower heights wouldn’t be restricted.

The towers would be required to be a certain distance from each other. The smallest distance reviewed in the report is 50 feet, and the largest is 100 feet.

The city’s Plan Commission adopted the group’s report and has recommended the City Council approve changes to allow for the largest buildings under the proposed rules, with towers separated by 50 feet. But in their adoption, they directed city staff to gather public input and will hold a hearing on the matter in March.

The city is now seeking input from the public on the proposed changes.

This rendering shows the largest structure that would be allowed under proposed rules, with towers limited to 18,750 square feet per floor above a 10-foot tall base. Shadows appear as they would on May 1. (City of Spokane)

The process to change city rules was kicked off by David Peterson, an executive at Goodale & Barbieri Company. A letter he wrote to the Spokane City Council in January 2017 said his development company was “deeply concerned” the height restrictions were “hindering development and creating unintended consequences for residential housing and commercial development.”

Peterson’s letter was quickly followed by one from Andrew Rolwes, the public policy and parking manager at the Downtown Spokane Partnership, echoing Peterson’s sentiment.

Peterson does not own any of the properties that would be affected by the changes, but he said Friday that he approached the city to lift the restrictions at the request of the properties’ two owners.

“I know both of them very well and have worked with them,” he said. “They’re fully aware of what’s happening and they asked me to get involved and do something. This is coming from the direction of the owners of these parcels.”

Peterson called the two properties in question “opportunistic blocks” that call for more than a “seven-story building.”

“A seven-story building just doesn’t do that property justice, in my opinion,” Peterson said. “We need to create something that all of Spokane would be proud of. We need something that’s going to generate a spark. A seven-story building is not going to generate a spark.”

Peterson said there were no specific plans for the properties, but envisioned a mixed-use building with retail, office space and living units.

This rendering shows the smallest structures proposed under a new set of rules, with towers above 100 feet limited to 11,0000 square feet per floor, lessening the amount of shadow to fall on the park. Shadows appear as they would on May 1. (City of Spokane)

The largest property owner is Dru Hieber, whose family has owned the Bennett Block and surrounding properties for generations. Hieber and her family own the vacant land on the western-most block between Howard and Stevens, which constitute about 1.5 acres and is assessed at more than $4.2 million.

Hieber and her family also own three vacant parcels in the block occupied by the Liberty Building through various companies, which are assessed at $1.4 million.

Hieber did not return a call seeking comment for this article, but in an interview in December she said she had no immediate plans for the vacant blocks. She said she wanted to wait to develop the land until more people were living downtown.

The remaining vacant parcels not owned by Hieber on the eastern block are owned by a company called PAC Operating, an arm of a real estate investment firm called Palmtree Acquisition Corporation. Its parcels are assessed at $2.2 million.

The Palmtree Acquisiton Corporation is listed by the state as being headquartered in Delaware and San Francisco. Peterson said the owner doesn’t live in the state, and declined to share his name.

The properties owned by Hieber and PAC Operating are a mishmash of 13 different parcels divided along historical lines where old buildings once sat. Another property, the site of the Sushi.com restaurant, is included on the land identified as ready for development in the city report and is the only one not currently used for parking.

The changes to height restrictions isn’t the only thing that may spur development on these lots. A bill is making its way through the state Legislature that would offer developers a 10-year break from taxes on any project they build on what is now a surface parking lot, an idea that came from Spokane to encourage construction on lots.

This week, that bill passed a major hurdle when the state Senate Economic Development and International Trade Committee approved it by a 5-0 vote. It’s now headed to the Rules Committee ahead of a Senate floor vote.

Kevin Freibott, an assistant planner at the city who helped form the proposed height rule changes, said the Plan Commission will hold a hearing in March following the public comment period and make a final recommendation.

The City Council is anticipated to consider the rules in April or May.