Lawrence probably will look markedly different over the next 20 years because of a document the Lawrence-Douglas County Planning Commission is scheduled to approve tonight.

Commissioners are to consider approval of the community’s new development code, which will replace the city’s 38-year-old zoning code. Lawrence city commissioners must give final approval to the plan before it takes effect.

The document addresses a variety of issues, including strategies to improve housing affordability, methods for making retail and residential developments more compatible, and systems for streamlining the development process.

Both city and development leaders said the new code would determine the size, shape and scope of the city’s development for years to come.

“This is the document that says exactly what you can do when it comes to development,” said Phil Struble, president of Landplan Engineering. “This is going to change the complexion of Lawrence for the next 20 years.”

The new code is meant to make for a more understandable and predictable development process, which ultimately would lead to greater consensus about projects in the community, said Sheila Stogsdill, assistant director of planning for the Lawrence-Douglas County Planning Department.

“A lot of times we hear concerns from developers who say, ‘Tell us what we need to do and we can do it, but don’t wait until I’ve already created a plan and then tell me what I need to do,'” Stogsdill said. “We’re hoping this will create a more streamlined process for the development community and the neighborhoods.”

Among the issues the code would address:

• Affordable housing: The code would create two new residential zoning categories that would allow for significantly smaller building lots than possible today. The code would allow single-family lots to be as small as 3,000 square feet, compared with the current 7,000-square-foot minimum. That would allow twice as many homes on an acre of land. Planners and developers are hoping the change would reduce housing prices by making land costs a smaller part of a home’s overall price.
• Compatibility: The proposal calls for larger setback areas and more landscaping to buffer residential developments from nonresidential uses, such as shopping centers or industrial areas.
• Notification: The new code would require developers to provide written notice to neighborhood associations when a rezoning is proposed for their neighborhood. Currently, only residents within 200 feet of the proposed rezoning must be notified.
• Home occupations: City ordinances do not allow any home occupation that employs a person who doesn’t live at the home. The new code would allow for some home occupations that employ one person who does not live at the home.

The Lawrence-Douglas County Planning Commission will take public comment on the proposed development code for the city at its meeting at 6:30 p.m., today at City Hall, Sixth and Massachusetts streets.

• Streamlining: The code would give planning staff members more authority to administratively approve parts of projects rather than making them go through the City Commission or Planning Commission. The largest change would be that site plans — which show the size and location of buildings, roads, parking lots and other similar details — would be approved by planning staff members. Currently city commissioners approve site plans.

The proposed code has been met with mixed reactions. Gwen Klingenberg, a steering committee member of the West Lawrence Neighborhood Assn., likes the idea.

“I think it is going to encourage a lot more talking between developers and neighborhoods,” said Klingenberg, who said she also likes the new buffering requirements.

Price Banks, a Lawrence land use attorney and former director of the Lawrence-Douglas County Planning Department, said the format and regulations of the proposed code were overly confusing.

“We ought to be working toward something that is user-friendly, and we just can’t seem to get there,” Banks said.