Three bottlenecks that slow residential permits

Anyone working in residential design can feel the gap between how many homes we need and how slowly they get approved.

Harvard’s Joint Center for Housing Studies estimates that the United States is short millions of homes and still underbuilding compared with demand.  At the same time, federal data shows that permit activity has been choppy, with single family construction only slowly recovering and multifamily permits trending down in many markets.

The result on the ground is familiar: long queues at building departments and projects that sit in “plan review limbo” longer than anyone would like.

We cannot control staffing levels inside city hall. We can control what shows up in the reviewer’s inbox.

From our work with architects, builders, and engineers, three bottlenecks come up again and again.

Bottleneck 1: Coordination that happens at the end, not the beginning

On a typical project, architecture, structural, and MEP often move in parallel. Everyone is doing good work. The trouble is that most of the real coordination happens late.

By the time the full set is assembled, you discover:

• A beam that conflicts with a duct run

• Plumbing stacks that do not align with framing

• Openings, headers, and loads that changed in one model but not the others

Industry studies have found that coordination problems and rework can consume a significant share of construction effort and cost.  In plan review, those same issues show up as comments, RFIs, and another round of revisions.

How Spacial helps

At Spacial, all disciplines run through one coordinated workflow. Our AI agents scan architectural backgrounds and engineering models for:

• Clashes between structural and MEP routes

• Inconsistent loads, spans, or support conditions

• Details that do not match the latest plan set

Our licensed structural and MEP engineers then review those flags, make the design calls, and deliver a unified, permit ready engineering package. Most projects move from intake to a coordinated, stamped set in about 7 to 10 business days on typical single family work.

That does not make plan review instant, but it removes a big source of late surprises.

Bottleneck 2: Local codes and amendments that slip through the cracks

Building codes are not one book. Cities and counties adopt base codes, then layer on local amendments, handbooks, and informal preferences from the authority having jurisdiction.

Common examples include:

• Jurisdiction specific shear wall detailing or nailing patterns

• Local energy requirements that go beyond state minimums

• Preferred ways to show egress, fire separation, or wildland urban interface details

Many building departments publish lists of the most common corrections they issue, and “does not meet local amendments” shows up often.  Even strong sets can come back with comments simply because one local nuance was missed.

How Spacial helps

Because our team has worked across hundreds of municipalities, we intentionally build local code knowledge into our process. For each region, we track:

• City specific checklists and plan review comments

• Local interpretations of structural and energy requirements

• Formatting and documentation preferences for submittals

Our AI agents surface city specific rules while engineers are still designing, not after submittal. That helps reduce avoidable comments that come from “We follow the base code, but your city wants it shown this way.”

Bottleneck 3: Incomplete calculations and details

The third bottleneck is simple: the reviewer cannot approve what they cannot see.

Across building departments, the same missing pieces tend to trigger comments:

• Structural calculations that do not match the framing plans

• Mechanical, electrical, or plumbing schedules that are partial or inconsistent

• Energy documentation that is started but not fully coordinated with the envelope and equipment selections

Guides from cities and industry groups repeatedly point to incomplete drawings and missing calculations as top reasons for delays.

How Spacial helps

Spacial’s workflow is set up so that structure, MEP, and energy move together. Our AI agents check for:

• Missing or mismatched structural and MEP calcs

• Open loops in schedules, notes, and details

• Energy reports that do not line up with the actual assemblies and systems

Licensed engineers own the final deliverables. They review every sheet, validate the assumptions, and stamp the set. The goal is a package that answers most of the reviewer’s questions up front.

What this means for residential architects and builders

No one can promise how long a specific city will take to approve a project. Workloads, staffing, and local priorities are outside any engineer’s control.

What we can do is make sure that when your project enters the queue, it arrives as a clean, coordinated, and complete submittal.

For our partners, that looks like:

• One partner for structural, MEP, and energy engineering instead of three separate vendors

• AI agents that do the repetitive scanning so engineers can focus on judgment and constructability

• A stamped, permit ready engineering set in about 7 to 10 business days on typical residential projects, so you can apply sooner and respond to comments faster

Plan review will always involve some back and forth. Our job at Spacial is to help make that loop tighter, more predictable, and less painful so you can spend more time designing homes and less time chasing corrections.

If you are interested in seeing how this works on a real project, we are always happy to walk through a recent set and show exactly where our team and technology stepped in.