Case Studies of Pre-Approved Housing Plans: A Strategic Tool for Accelerating Affordable Infill Development
Authored By: Eric Williams, Mark Bennett, Jasmine Farhat, & Lauryn Thomas
Executive Summary
The Detroit Justice Center’s recent white paper on pre-approved housing plans incorporates the findings below Specifically, that pre-approved housing plans represent an emerging strategy to address critical barriers in small-scale residential development: high soft costs, unpredictable permitting timelines, and the difficulty of making infill projects financially viable By offering code-compliant, pre-reviewed building designs paired with streamlined permitting processes, municipalities can dramatically reduce the time and expense required to deliver housing on vacant and underutilized urban lots
The case studies below examine four diverse implementations of pre-approved housing plan programs across the United States, analyzing their design, outcomes, and transferable lessons. The case studies span different contexts from legacy industrial cities confronting widespread vacancy to rural counties serving owner-builders to disaster recovery zones requiring rapid reconstruction.
Key Findings:
● Pre-approved plan programs can reduce permit approval times from months to 1-2 weeks when combined with as-of-right zoning reforms
● Programs work best when they package more than just drawings successful implementations include clear workflows, online portals, cost estimation tools, and builder education
● As of early 2024, Kalamazoo, Michigan had delivered approximately 48 homes using pre-permitted plans, demonstrating scalable impact
● Strategic public-sector prototype builds help identify and eliminate hidden barriers (such as unexpected utility fees and other infrastructure requirements) before private developers face them
● The approach is highly adaptable: the same core strategy serves dense urban infill, rural self-builds, and post-disaster reconstruction
● Utilizing modular housing can further reduce delivery times and overall costs
Recommendations
for Jurisdictions Considering Pre-Approved Plans:
1 Align zoning with plan catalog to ensure typical lots are buildable as-of-right
2 Develop demonstration projects to surface and resolve implementation challenges
3 Create comprehensive support infrastructure beyond plan drawings
4. Layer multiple funding sources to close feasibility gaps
5. Leverage state-level toolkits and technical assistance where available
Introduction: The Housing Production Challenge
American cities face a persistent housing affordability crisis driven in part by supply constraints While attention often focuses on large-scale development, infill housing on scattered vacant lots particularly in legacy cities with extensive land bank inventories—represents significant untapped capacity However, traditional development processes create prohibitive barriers for small-scale projects
Custom architectural design, iterative plan review, variance hearings for nonconforming lots, and opaque permitting procedures impose costs that can exceed $50,000 per unit in soft expenses alone For modest infill homes where construction costs already challenge market appraisals, these front-end burdens often render projects financially infeasible Small builders and community development corporations, who might otherwise fill this niche, lack the capital reserves and staff capacity to absorb such risks.
Pre-approved housing plans address this market failure through a simple but powerful intervention: municipalities pre-review a catalog of code-compliant, context-appropriate designs and create expedited approval pathways for projects that use them. When paired with complementary zoning reforms and transparent administrative processes, this approach can compress timelines, reduce uncertainty, and make small-lot infill economically viable.
This paper presents detailed case studies from four jurisdictions that have pioneered different models of pre-approved plan programs, followed by cross-cutting analysis and recommendations for replication
Case Study 1: Kalamazoo, Michigan – Comprehensive Urban Infill Strategy
Context and Challenge
By 2015, the Kalamazoo County Land Bank controlled 267 derelict properties scattered throughout the city Traditional development economics failed: construction costs exceeded achievable sale prices, creating a cycle of disinvestment where vacant lots remained vacant despite evident housing need Private developers avoided these sites, and even mission-driven nonprofits struggled to make projects pencil without substantial subsidies
The city recognized that fixing this problem required intervention across multiple pressure points not just in the physical planning realm but in finance, regulation, and market development.
Program Design and Implementation
Pre-Approved Plan Portfolio
Kalamazoo developed a diverse catalog of pre-permitted housing types designed to fit the city's historic lot patterns and architectural vernacular Working with architects Jennifer Griffin (J. Griffin Design) and Jennifer Settle (Opticos Design), the city created nine distinct building types:
● Single-family homes (standard and narrow formats)
● Three duplex configurations (stacked, side-by-side, and front-back)
● One-story cottage
● Carriage house/accessory dwelling unit
● Small plexes (4-unit and 12-unit buildings)
Each plan underwent full building code review by city staff before being added to the catalog, eliminating the need for iterative design review when applicants use them. Multiple facade elevations within each type provide visual variety and prevent monotonous repetition.
Streamlined Process
The program establishes a clear six-step pathway published on the city's website:
1. Choose a plan from the online catalog
2 Verify zoning eligibility using the city's interactive map
3 Prepare a simple site plan (DIY acceptable; professional stamp only if required)
4 Submit online application through BS&A portal, selecting "Pre-Approved Plan" permit type
5. Pay permit fees
6 Receive city review and utilities verification
Most applications that encounter no site-specific conflicts receive approval within 1-2 weeks after fee payment a dramatic reduction from typical multi-month timelines
Complementary Zoning Reforms
Recognizing that even perfect plans cannot overcome prohibitive zoning, Kalamazoo undertook parallel regulatory modernization The city legalized accessory dwelling units, reduced minimum lot sizes and setback requirements, and relaxed parking mandates These changes ensured that typical infill lots previously deemed unbuildable could now accommodate the pre-approved designs as-of-right, without variance proceedings.
Enabling Financing and Partnerships
Kalamazoo assembled a sophisticated civic finance ecosystem to support program implementation:
● The Kalamazoo Attainable Homes Partnership (convening the Home Builders Association of Western Michigan and LISC) provided delivery capacity and gap financing
● The Foundation for Excellence supplied predevelopment and programmatic support
● Kalamazoo County's "Homes for All" millage created additional capital resources
● Federal American Rescue Plan Act funds financed specific demonstration projects, including three pre-approved cottages on Land Bank sites targeted to households earning 100% or less of area median income
Risk Mitigation Through Prototypes
Rather than simply publishing plans and hoping the market would respond, the city co-developed early demonstration projects with Kalamazoo Neighborhood Housing Services (KNHS). The first prototype a stacked duplex with standalone ADU unveiled in October 2022—served a crucial function beyond adding two housing units: it revealed hidden implementation barriers.
For example, the pilot exposed an unexpected $18,000 water connection fee that would have killed project feasibility had individual small developers encountered it first The city addressed this and similar obstacles before scaling the program, effectively de-risking participation for private builders.
Outcomes and Impact
Production Results
By early 2024, approximately 48 homes had been completed or were under construction using Kalamazoo's pre-permitted plans The program continued to gain momentum through 2025, with the city allocating additional ARPA funds and receiving national recognition from the Congress for the New Urbanism Charter Awards
Timeline and Cost Improvements
Projects using pre-approved plans benefit from:
● 1-2 week permit approvals (versus months for custom designs)
● Eliminated design iteration costs
● Reduced architectural fees (or zero fees when builders use plans directly)
● No variance hearing expenses or delays
The city provides downloadable cost estimation spreadsheets for each building type, enabling builders to financial pro forma projects with confidence before acquiring sites
Before/After Permit Timeline (Kalamazoo):
Stage Before Pre-Approved Plans After Pre-Approved Plans
First Plan Review 6–8 weeks 1–2 weeks Iterations 2–3 resubmittals 0–1
Total Time to Permit 4–6 months 3–5 weeks
Neighborhood Integration
Because the pre-approved plans mirror Kalamazoo's traditional massing and architectural character, they integrate seamlessly into established neighborhoods. This compatibility reduces neighbor opposition and avoids the "out of place" appearance that sometimes accompanies infill development, making projects more politically sustainable.
Energy Performance
Early builds emphasized all-electric systems and high-performance building envelopes, including energy recovery ventilators and triple-pane windows These features reduce lifetime operating costs for residents an important affordability dimension often overlooked in discussions focused solely on initial construction costs
National Recognition and Replication Potential
Major planning organizations including Strong Towns, the National Association of Home Builders, and the Congress for the New Urbanism have featured Kalamazoo's program as a replicable model The city's comprehensive approach combining plans with zoning reform, prototype builds, and coordinated financing has become a reference point for other communities considering similar initiatives
Challenges and Adaptations
The program was not without obstacles Infrastructure surprises beyond the water connection fee appeared during early builds Some builders were unfamiliar with missing-middle typologies like side-by-side duplexes and required education and technical assistance Market appraisals sometimes lagged behind actual construction costs, necessitating gap financing
Kalamazoo addressed these challenges through its partnership model using nonprofit developers for demonstration projects, providing technical support through KNHS, and assembling flexible funding sources to bridge feasibility gaps.
Case Study 2: Ecorse, Michigan – Pragmatic Small-Lot Solutions
Context and Challenge
Ecorse, a smaller municipality than Kalamazoo, faced similar structural challenges: a legacy of vacant and undersized parcels where conventional custom design and review cycles made modest new construction financially marginal. City staff needed an approach that could work within limited administrative capacity while still accelerating infill
Program Design
Streamlined Plan Catalog
Ecorse created a focused portfolio of four ranch-style house plans, all featuring:
● All-electric systems to control operating costs and simplify construction
● Slab-on-grade foundations suited to small lots and fill-sensitive soils
● Compact footprints designed for typical Ecorse parcel dimensions
Each plan completed preliminary review by both Planning and Building departments before publication, allowing applicants to skip most design iteration.
Clear Online Pathway
The city hosts its pre-approved plans and supporting materials on a dedicated program webpage within the Community Development section of the city website The program emphasizes complete initial submittals a clear checklist helps applicants provide all required site-specific information (site plan, utility connections) upfront, keeping reviews efficient
Before/After Permit Timeline (Ecorse)
Stage Before Pre-Approved Plans After Pre-Approved Plans
Design Procurement 1–2 months 0 (plans provided)
First Plan Review 6–8 weeks 1–2 weeks
Iterations Multiple resubmittals 0–1
Total Time to Permit 3–5 months 3–4 weeks
Note: Timelines for Ecorse are illustrative based on program design; replace with verified local data as available
State Alignment
Ecorse's approach complements the Michigan Economic Development Corporation's broader Permit-Ready and Pattern Book Homes initiatives, which provide any Michigan municipality with open-source stamped plans for duplexes and quadplexes. This state-level infrastructure reinforces local efforts and reduces startup costs for smaller cities
Outcomes and Transferable Insights
While Ecorse has not published production statistics comparable to Kalamazoo's, the program demonstrates that even resource-constrained municipalities can implement effective pre-approved plan systems. The focus on simple, repeatable house types suited to local conditions—rather than attempting comprehensive typological diversity represents a pragmatic path for smaller jurisdictions
Key elements of Ecorse's approach that other cities might replicate include:
● A plain-English program webpage explaining what "pre-approved" means in concrete terms
● Downloadable plan sheets available to any interested builder
● A one-page submittal checklist paired directly with the online permit portal
● Strategic alignment with state-provided plan libraries to expand options without local design costs
Case Study 3:
Yavapai County, Arizona – Supporting Rural Owner-Builders
Context and Challenge
Yavapai County encompasses a large, predominantly rural area where owner-builder projects are common but administrative capacity is limited Staff observed recurring patterns: incomplete submittals, missing technical details, and preventable delays that frustrated applicants and consumed review resources
The county needed a solution that would serve dispersed rural residents, many building modest homes on remote parcels, while improving throughput for plan review staff
Program Design
"A Home of My Own!" Free Plan Library
The county offers free, downloadable single-family home plans to anyone building within unincorporated areas By eliminating architectural design fees which can be prohibitively expensive or simply unavailable in remote areas the program removes a significant financial and logistical barrier for rural owner-builders
Comprehensive Guidance Materials
Beyond the plans themselves, Yavapai County publishes supporting documents designed to improve first-cycle approval rates:
● Residential Inspection Checklist detailing all required plan elements
● "Common Omissions & Mistakes" guide highlighting where applicants typically fall short
● Clear specifications for plan scale, sheet size, and site plan requirements
These materials effectively transfer knowledge from staff to applicants, reducing the coaching burden on reviewers and accelerating approvals
Flexible Integration
While the county encourages use of its free stock plans, the published submittal standards also serve applicants who choose custom designs. The program thus
improves consistency across all residential permit applications, not just those using pre-approved plans
Outcomes and Transferable Insights
Yavapai County's model illustrates how pre-approved plan programs can address rural development contexts distinct from urban infill. The program's success factors include:
Accessibility Focus: Free plans eliminate a significant cost barrier, particularly valuable where professional design services are scarce or expensive.
Educational Infrastructure: Detailed checklists and common-error guides reduce rework cycles and shift staff time from remedial coaching to substantive review
Process Transparency: A clear, single landing page routes applicants to all necessary permits and licenses, simplifying navigation through bureaucratic requirements.
Before/After Permit Timeline (Yavapai County):
Stage Before Pre-Approved Plans After Pre-Approved Plans
First Plan Review 6–10 weeks 1–2 weeks Iterations 2–3 resubmittals
Total
Note: Timelines for Yavapai County are illustrative based on program design; replace with verified local data as available
The county's approach demonstrates that pre-approved plan programs need not be limited to dense urban contexts or complex typologies Simple, well-documented processes serving rural single-family construction can achieve similar benefits in timeline reduction and cost predictability
Case Study 4: Lahaina, Hawaii – Disaster
Recovery and Rapid Reconstruction
Context and Challenge
The August 2023 Lahaina wildfire destroyed more than 2,000 buildings and displaced thousands of residents Maui County faced an unprecedented reconstruction challenge. Historically, the county's permitting system operated slowly median processing times for multifamily projects approached 400 days Applying this timeline to fire recovery would have been catastrophic, extending displacement and deepening economic hardship
The county recognized that disaster recovery required extraordinary interventions across regulatory, administrative, and design-support dimensions
Program Design
Expedited Permitting Infrastructure
Maui County established a dedicated Expedited Permitting Center and created a special Emergency/Disaster Recovery Building Permit pathway for repair, reconstruction, and new construction in fire-affected areas This organizational structure separated disaster recovery projects from routine permit queues, ensuring they received priority processing
Before/After Permit Timeline (Lahaina):
Note: Timelines for Lahaina are illustrative estimates; replace with verified county data as available.
Regulatory Relief Through Ordinance 5780
Many properties destroyed in the fire were legal but nonconforming to current zoning a common situation in older neighborhoods Requiring full compliance with contemporary standards would have triggered expensive variances or forced rebuilding in configurations incompatible with original uses
Maui County addressed this through temporary but substantial regulatory flexibility Ordinance 5780, effective March 24, 2025, gives eligible property owners until April 1, 2029 to obtain permits and complete reconstruction of previously legal nonconforming structures This four-year window eliminates variance proceedings while maintaining essential safety and building code compliance.
Pre-Designed Plans Library
A coalition of nonprofits and local architecture firms organized as Helping Maui curated a library of 1-6 bedroom house plan packages Many of these plans are offered free or at reduced prices specifically for wildfire survivors The library provides immediate, permit-ready design options, eliminating months of design time for households eager to rebuild
Comprehensive District Planning
The county launched the Rebuild Lahaina Plan to coordinate recovery at a district scale. Rather than allowing purely parcel-by-parcel reconstruction, this area plan integrates housing with mixed-use development, parks, transit facilities, and public infrastructure while honoring the West Maui Community Plan and National Historic Landmark District guidelines.
This planning framework ensures that rapid reconstruction occurs within a coherent vision that addresses transportation, cultural resources, environmental resilience, and community character
Early Indicators and Ongoing Challenges
By June 2025, community progress updates indicated 385 residential permits issued, 143 applications in processing, and 20 homes completed While these numbers represent progress through the pipeline, full recovery remains years away
Affordability and Displacement Pressures
Disaster recovery has coincided with severe rent increases and deepened poverty for many households The county is deploying Community Development Block Grant Disaster Recovery funds through the Hoʻokumu Hou program to provide direct support to survivors and prevent permanent displacement from the island
Balancing Speed with Sensitivity
Lahaina's status as a National Historic Landmark District and its profound cultural significance require that reconstruction respect historical and environmental values. The Rebuild Lahaina Plan provides the framework for achieving this balance, ensuring that expedited processes serve community-defined recovery goals rather than short-term expediency.
Transferable Insights for Disaster Recovery Contexts
Lahaina's experience offers specific lessons for jurisdictions facing post-disaster reconstruction:
Stand Up Dedicated Administrative Capacity: Create a one-stop expedited center and establish disaster-specific permit pathways separate from routine operations.
Provide Immediate Design Options: Offer a vetted plan library (free or discounted where possible) to eliminate design timeline for households who need to rebuild quickly
Codify Time-Limited Regulatory Flexibility: Use ordinances to prevent unnecessary variance hearings for legal nonconforming properties while maintaining safety standards
Integrate Parcel and District Planning: Ensure rapid individual reconstruction occurs within a coherent vision for community-scale recovery
Cross-Cutting Analysis
What Makes Pre-Approved Plan Programs Effective?
Analysis across these four case studies reveals common success factors and adaptable principles:
1 Comprehensive Support Infrastructure
None of these programs simply published drawings and assumed uptake would follow Successful implementations package plans with:
● Clear, published workflows explaining each step from plan selection to certificate of occupancy
● Online permitting portals optimized for pre-approved plan applications
● Cost estimation tools and financial planning resources
● Submittal checklists and guidance on common errors
● Technical assistance for builders unfamiliar with particular typologies
This comprehensive approach recognizes that reducing friction requires addressing administrative, financial, and knowledge barriers not just design standardization
2 Context-Responsive Typologies
Effective plan catalogs reflect local built form, parcel patterns, and market conditions:
● Kalamazoo's diverse portfolio (from cottages to 12-plexes) addresses varied lot sizes and neighborhood characters across a mid-sized city
● Ecorse's focused ranch designs solve for small lots with fill-sensitive soils
● Lahaina's library accommodates reconstruction across a range of household sizes while respecting historic district guidelines
Generic, one-size-fits-all plans imported from other jurisdictions rarely succeed. Local customization matters
3 Regulatory Alignment
Pre-approved plans only accelerate development when zoning allows them to be used as-of-right Kalamazoo's concurrent zoning reforms legalizing ADUs, reducing lot minimums and setbacks, easing parking requirements proved essential to program success Plans compatible with current code but prohibited by zoning accomplish nothing
Effective programs audit existing zoning against the plan catalog and reform regulations to ensure typical lots can accommodate pre-approved designs without variances
4 Strategic Demonstration Projects
Kalamazoo's prototype builds with KNHS served multiple functions: proving feasibility, identifying hidden barriers (like unexpected utility fees), building market confidence, and training local builders on unfamiliar typologies Public-sector demonstration projects shift risk from private developers to entities better positioned to absorb it and convert lessons learned into systemic improvements.
5. Layered Financing
Many pre-approved plan programs target infill sites where market appraisals lag construction costs or serve populations with limited access to conventional financing. Programs that succeed assemble multiple capital sources:
● Foundation and philanthropic support (Kalamazoo's Foundation for Excellence)
● County or regional funding mechanisms (Kalamazoo County's "Homes for All" millage)
● State programs and technical assistance (Michigan's Permit-Ready/Pattern Book Homes)
● Federal one-time dollars (ARPA funds in Kalamazoo, CDBG-DR in Lahaina)
● CDFI and nonprofit lender participation (LISC in Kalamazoo)
This layered approach closes feasibility gaps and enables program scale
Measuring Success: What Outcomes Matter?
Pre-approved plan programs can be evaluated across multiple dimensions:
Production Volume: Kalamazoo's 48 units by 2024, with continued growth, demonstrates meaningful scale Lahaina's 385 permits by mid-2025 shows rapid pipeline development in crisis conditions.
Timeline Reduction: Kalamazoo's 1-2 week approvals versus months for custom designs represent 80-90% time savings critical for project feasibility and cash flow
Cost Predictability: Published cost estimation tools, eliminated design iteration, and reduced soft costs make financial modeling reliable, enabling small builders to compete
Market Activation: Programs succeed when they enable builders who previously avoided difficult sites (vacant lots, small parcels, nonconforming properties) to take on projects.
Neighborhood Integration: Plans that respect local character reduce opposition and support political sustainability
Equity Outcomes: Programs that pair pre-approved plans with affordability set-asides, targeted subsidies, or disaster relief serve residents most affected by housing scarcity
What Doesn't Work: Common Pitfalls
The case studies also illuminate approaches to avoid:
Plans Without Process Reform: Publishing designs while leaving opaque or adversarial permitting procedures intact fails to address core barriers
Regulatory Incompatibility: Pre-approved plans that require variances or conditional use permits sacrifice their primary advantage.
Insufficient Design Quality: Generic, context-insensitive plans that clash with neighborhood character invite opposition and undermine program legitimacy
Lack of Builder Engagement: Programs developed without input from local building community may produce plans that are theoretically sound but impractical to construct.
No Implementation Support: Expecting market uptake without demonstration projects, technical assistance, or gap financing often results in unused plan libraries
Conclusion
Pre-approved housing plans represent a pragmatic, scalable intervention to address critical barriers in small-scale residential development. By reducing soft costs, compressing timelines, and providing process and regulatory predictability, these programs enable housing production on sites that conventional development approaches would leave vacant.
The case studies examined here spanning urban infill, rural construction, and disaster recovery—demonstrate both the versatility of the core strategy and the importance of tailoring implementation to local context Success requires more than publishing plan sets: effective programs package designs with streamlined permitting procedures, regulatory reforms, demonstration projects, technical assistance, and coordinated financing.
For jurisdictions struggling with housing production gaps, persistent vacancy, or post-disaster reconstruction needs, pre-approved plan programs offer a tested pathway forward The approach will not solve the housing crisis alone regional challenges require regional responses, and deep affordability demands sustained public investment But within its domain, the strategy works
Kalamazoo's 48 homes, Lahaina's 385 permits, and the steady activation of small builders in Ecorse and Yavapai County prove that thoughtfully designed programs can move the needle. As more jurisdictions implement similar initiatives and share lessons learned, the model continues to evolve and improve
The path forward is clear: cities and counties willing to standardize compliant designs, reform constraining regulations, prototype new approaches, and support builders through the transition can unlock substantial infill capacity The tools exist
The question is implementation
References and Resources
Case Study Sources
Kalamazoo, Michigan
● City of Kalamazoo, Pre-Approved Housing Plans program page: https://wwwkalamazoocityorg/Community/Community-Development-Housi ng-Programs/Pre-Approved-Housing-Plans
● Congress for the New Urbanism, "Kalamazoo to Build Pre-Approved Cottages" (December 19, 2024)
● Congress for the New Urbanism, "Pre-Approved Path to Rebuild Neighborhoods" (May 22, 2025)
● Second Wave Media, Kalamazoo coverage (October 2022, March 2025)
● Planetizen, news brief (February 14, 2024)
Ecorse, Michigan
● City of Ecorse, Pre-Approved House Plans: https://ecorsemiprod3 muniwebcom/Departments/Community-Developmen t/Pre-Approved-House-Plans.aspx
● Better Cities Project, "Pre-Approved Housing Plans: A Smarter Path to More Affordable Homes"
Yavapai County, Arizona
● Yavapai County Development Services, "A Home of My Own!" program: https://www.yavapaiaz.gov/Development-and-Permits/Development-Services /Residential-Homes/A-Home-of-My-Own-Program
