Johnston homeowners take on some of the most ambitious projects in Polk County: new homes, additions, basement finishes, kitchens, and decks. Every project starts with the same question. How long is this going to take? This guide gives honest 2026 timelines for the most common project types, explains what drives delays in Johnston, and shows you when to start planning.
TLDR: Build timelines in Johnston range from a few weeks for a deck to 8 to 12 months for a custom home. Johnston reviews most permits in 5 to 7 working days, and Iowa’s seasons matter: spring starts run smoothest, while winter slows foundation and concrete work. Plan your selections early, since late decisions are the top cause of delay. Read on for timelines by project type.
You have a project in mind and a calendar to plan around. Maybe you need to line up temporary housing, time a move, or just know when you can stop living in a construction zone. The honest answer depends on the project, the season, and how fast decisions get made.
This guide walks through realistic timelines for five common Johnston projects, the local permit process, and the Iowa-specific factors that speed things up or slow them down. These are planning estimates, not guarantees, but they will help you plan with your eyes open.
Timeline by Project Type
Here is the big picture before we go deep on each. Use it to find your project, then read the matching section for detail.
| Project Type | Planning + Permits | Active Build | Total Range | Best Start |
|---|---|---|---|---|
| Custom home build | 2 to 4 months | 5 to 8 months | 8 to 12 months | Late winter |
| Home addition | 3 to 6 weeks | 2 to 5 months | 3 to 7 months | Spring |
| Basement finish | 1 to 2 weeks | 5 to 12 weeks | 6 to 14 weeks | Spring or fall |
| Kitchen remodel | 2 to 4 weeks | 6 to 12 weeks | 8 to 16 weeks | Any season |
| Deck build | 1 to 2 weeks | 2 to 6 weeks | 3 to 8 weeks | May to September |
Timelines are estimates based on typical Central Iowa conditions for 2026. Actual duration varies by scope, site conditions, weather, permit timing, material lead times, and how fast decisions get made. Get a written timeline from your contractor before committing to any schedule.
Pro Tip 1: Build your personal timeline backward from your move-in or event date, then add a buffer. Projects rarely finish early, and a cushion saves stress.
Johnston’s Permit Timeline: What to Plan For
Most timeline questions in Johnston start with permits, so start here. The Johnston Building Department reviews plans in a minimum of 5 working days, and a typical review runs up to 7 working days for most residential projects.
| Step | Who Does It | Timeline |
|---|---|---|
| Submit application | You or your contractor | Day one |
| Plan review | Building Department | 5 to 7 working days |
| Permit issued | Building Department | After review passes |
| Construction | Your contractor | Varies by project |
| Final inspection | Building Department | At project end |
| Certificate of Occupancy | Building Department | Minimum 2 business days |
Electrical, plumbing, and mechanical work each need their own permits, handled by licensed subcontractors. A registered contractor coordinates those subs so the permits and inspections line up. After your final inspection passes, the Certificate of Occupancy takes a minimum of 2 business days, so do not plan to move in the same afternoon.
Two Johnston rules catch people off guard. Work must begin within 180 days of permit issuance, so do not pull a permit far ahead of your start. And Johnston restricts concrete pours by temperature, using the National Weather Service 24-hour forecast: no concrete at 10 degrees or below, and concrete must be covered for at least 48 hours at 25 degrees or below.
Pro Tip 2: Submit complete drawings the first time. An incomplete plan submission restarts the 5 to 7 day review clock, which is the easiest delay to avoid.
Pro Tip 3: Permit fees in Johnston are set by project value, not a flat rate. Call the Johnston Building Department at (515) 727-7778 for your exact figure rather than guessing.
Johnston is growing fast. In 2025, the city issued 608 building permits, including 98 single-family homes. That demand can affect review times, so schedule early.
Custom Home Build: 8 to 12 Months
A custom home is the longest timeline most homeowners will plan, and the one most worth getting right. In Iowa, expect 8 to 12 months from design to move-in, with most projects landing near 10 months. For national context, U.S. Census construction data shows production homes averaging 8 to 9 months and owner-built custom homes 12 to 13 months. You can read more on how long it takes to build a custom home in Iowa for the full breakdown.
The pre-build phase covers design, permits, and financing, and runs 2 to 4 months. Design takes 4 to 8 weeks, construction loan approval runs 4 to 6 weeks and often overlaps with design, and the city permit review takes 5 to 7 working days once plans are submitted.
Active construction runs 5 to 8 months. Foundation work takes 3 to 5 weeks, and Iowa’s frost line means footings must go at least 42 inches deep. Framing and roof take 4 to 6 weeks, mechanical rough-ins 2 to 4 weeks, insulation and drywall 2 to 3 weeks, and interior finishes 6 to 10 weeks. Interior finishes are the longest single phase because they involve many trades and many decisions.
Pro Tip 4: Design in winter, permit in late winter, and break ground in April. That sequence dodges the worst weather and gives the smoothest path to a 10-month build.
Pro Tip 5: Spring starts typically finish in 8 to 10 months. Winter groundbreaks run longer, often 11 to 14 months, because deep frost and cold slow foundation work.
Iowa weather shapes the schedule. Heavy spring rain stops earthwork and concrete, and the March to May mud season can add 1 to 3 weeks. Johnston’s clay soils slow excavation after wet periods. If you start a custom home for financing, our guide on financing your custom home build in Iowa walks through the loan side.
Home Addition: 3 to 7 Months
A home addition is the second most common major project, and the range is wide. Small room additions or bump-outs run 3 to 4 months. Mid-size additions like a bedroom suite or sunroom run 4 to 6 months. Large additions such as a second story or in-law suite run 5 to 8 months or more.
For a mid-size addition, expect design and estimate at 2 to 4 weeks, Johnston permit review at 1 to 2 weeks, foundation and footings at 2 to 4 weeks, framing and exterior at 3 to 5 weeks, mechanical rough-ins at 2 to 3 weeks, finishes at 4 to 8 weeks, and final inspection plus Certificate of Occupancy at 1 to 2 weeks.
Every Iowa home addition requires a building permit, with no exceptions. The structural tie-in to your existing home adds complexity that new construction does not have, and it must meet current code. Our guide on whether a second-story addition in Iowa is worth it covers the bigger-addition path in depth.
Pro Tip 6: Start exterior addition work between April and September. Frost line footings and cold-weather concrete rules make late-fall and winter starts slower.
Pro Tip 7: Budget extra time for the tie-in. Connecting new framing to an existing home often reveals surprises behind old walls that a new build never faces.
Basement Finishing: 6 to 14 Weeks
Many Johnston homes have unfinished basements, and finishing one is largely interior work, so weather has minimal impact. A basic family room with no bath or egress runs 6 to 8 weeks. A mid-range finish with a bathroom on an existing rough-in runs 8 to 10 weeks. A full suite with an egress window and new bath runs 10 to 14 weeks.
Johnston reviews the permit in 5 to 7 working days before work begins, and three inspections are required: under-slab if you add plumbing, framing and rough-in, and final. The Certificate of Occupancy takes a minimum of 2 business days. For ideas on using the space, see our best basement layouts for Iowa homes.
Two Iowa factors can add time. Radon testing is recommended before framing, and mitigation adds 1 to 2 weeks if levels are high. Moisture issues must be resolved first and can add weeks depending on severity.
Pro Tip 8: Test for radon before you frame, since 71.6 percent of Iowa homes test above the EPA action level. Catching it early adds a week or two; catching it after walls close costs far more.
Pro Tip 9: Cutting an egress window means exterior concrete work, so avoid frozen ground. Spring or fall starts also let you watch the basement through a wet season first.
Kitchen Remodel: 8 to 16 Weeks
A kitchen remodel is the most common interior remodel in Johnston’s move-up market. A basic cosmetic refresh runs 4 to 6 weeks. A mid-range remodel with new cabinets and some layout changes runs 8 to 12 weeks. A major remodel with moved walls and relocated plumbing runs 12 to 16 weeks or more.
Cabinet lead time is the single biggest variable. Stock cabinets ship in 1 to 2 weeks, semi-custom in 4 to 8 weeks, and custom in 8 to 14 weeks. A permit is required if the work includes electrical or plumbing changes.
Pro Tip 10: Lock every selection before demo starts. Cabinets, countertops, fixtures, and finishes chosen upfront keep the schedule on track; choosing mid-project resets it.
Pro Tip 11: Order cabinets first, then schedule demo around their arrival. Tearing out a working kitchen weeks before the cabinets show up just means longer without a kitchen.
Deck Build: 3 to 8 Weeks
A deck is a popular summer project and highly seasonal. A small attached deck runs 3 to 5 weeks total with the permit. A standard 16 by 20 deck runs 4 to 7 weeks. A large or covered multi-level deck runs 5 to 8 weeks.
Johnston reviews the permit in 5 to 7 working days, and footings must go at least 42 inches deep to clear the frost line. Composite decks take slightly longer than pressure-treated because they have more components. Our comparison of a wood deck versus a composite deck in Iowa helps you weigh the material choice.
Weather is the main driver. The best window is May through September. Deck footings cannot be poured in frozen ground, and spring mud season can delay footing work 1 to 2 weeks.
Pro Tip 12: Pull your deck permit in early spring so you are ready to pour footings the moment the ground thaws. Most decks can go start to finish in a single warm season.
How Iowa Seasons Affect Your Timeline
Season is one of the biggest factors you can actually plan around. Here is how each one plays out for Johnston projects.
| Season | Best For | Risk Factors |
|---|---|---|
| Spring (Apr to May) | Breaking ground, foundations | Mud season delays earthwork |
| Summer (Jun to Aug) | Decks, exterior work, framing | Peak demand for subs |
| Fall (Sep to Oct) | Basements, interior remodels | Shorter window before cold |
| Winter (Nov to Mar) | Interior work, planning, design | Concrete and frost limits |
Winter is not wasted time. It is the best season to design, line up financing, and get permits ready so you can break ground in spring. Interior projects like basements and kitchens move fine in winter since they are not weather-dependent.
What Makes Johnston Projects Take Longer
Most delays are preventable with the right information. Here are the top causes and how to avoid them.
| Delay Cause | Impact | How to Prevent |
|---|---|---|
| Late material selections | Days to weeks | Lock all choices before work starts |
| Incomplete permit submittal | 5 to 7 days | Submit complete drawings the first time |
| Iowa weather | 1 to 3 weeks | Plan around seasons |
| Material lead times | Weeks | Order custom items early |
| Mid-project changes | Days to weeks | Finalize the plan before construction |
| Subcontractor availability | Varies | Schedule early in a busy market |
| Radon or moisture findings | 1 to 4 weeks | Test and inspect before walls close |
Late material selections are the number one preventable delay. Incomplete permit submittals restart the review clock. Iowa weather, especially mud season and the concrete restrictions, stops outdoor work. Johnston’s fast growth means licensed trades are in high demand across Polk County, so book early.
Illustrative Johnston Timelines
Illustrative scenario: A Johnston couple built a 2,200-square-foot ranch with standard finishes. They started design in February, got permits in March, broke ground in April, and moved in December. Total: about 10 months.
Illustrative scenario: A Johnston family added a 400-square-foot main-floor bedroom and bathroom with no rough-in changes. Design took 3 weeks, the permit 6 working days, and construction 14 weeks. Total: about 5 months.
Illustrative scenario: A Johnston homeowner finished a 900-square-foot basement at a mid-range level on an existing rough-in, with radon mitigation added. The permit took a week and construction 8 weeks. Total: about 10 weeks.
Illustrative scenario: A Johnston family remodeled a kitchen with semi-custom cabinets on a 6-week lead time, new countertops, lighting, and plumbing. They locked selections before demo. Total: about 12 weeks.
Illustrative scenario: A Johnston homeowner built a 16 by 20 composite deck. The permit came in 8 days, footings went in mid-May, and construction ran 3.5 weeks. Total from first call to finished deck: about 6 weeks.
Frequently Asked Questions
Q: How long does it take to get a building permit in Johnston, Iowa? A: Johnston reviews plans in a minimum of 5 working days, typically up to 7 working days for most residential projects. Incomplete submissions restart the clock, so submit complete drawings. Electrical, plumbing, and mechanical work need separate permits. Confirm current details with the Johnston Building Department at (515) 727-7778.
Q: How long does it take to build a custom home in Johnston, Iowa? A: Expect 8 to 12 months from design to move-in, with most Central Iowa custom homes landing near 10 months. The pre-build phase of design, permits, and financing adds 2 to 4 months before ground breaks. Spring starts run fastest. These are estimates, so get a written timeline from your contractor.
Q: What time of year is best to start building in Johnston? A: Spring starts in April or May give the smoothest path. Design in winter, permit in late winter, and dig in April. Iowa’s frost line requires footings at least 42 inches deep, and Johnston restricts concrete below 25 degrees, which makes winter groundbreaking slower. Interior projects like basements and kitchens can start any season.
Q: How long does a home addition take in Johnston? A: Small additions run 3 to 4 months, mid-size 4 to 6 months, and large additions 5 to 8 months or more. Every addition requires a building permit, with about 5 to 7 working days for review. The tie-in to your existing home adds time. These are estimates; get a written timeline from your contractor.
Q: What causes the most delays in Johnston construction projects? A: The biggest causes are late material selections, especially cabinets, plus incomplete permit submittals, Iowa weather, mid-project changes, and subcontractor availability in Johnston’s busy market. Most are preventable by locking decisions early, submitting complete plans, and planning around the seasons. A registered contractor who knows the local process helps you avoid them.
Key Takeaways
Timelines by Project
- Custom home: 8 to 12 months, most near 10.
- Home addition: 3 to 7 months by size.
- Basement finish: 6 to 14 weeks; kitchen: 8 to 16 weeks; deck: 3 to 8 weeks.
Permits and Process
- Johnston reviews plans in 5 to 7 working days.
- Certificate of Occupancy takes a minimum of 2 business days.
- Work must begin within 180 days of permit issuance.
Iowa Seasonal Factors
- Frost line means footings at least 42 inches deep.
- No concrete below 10 degrees; cover it below 25 degrees.
- Spring starts run smoothest; winter is best for planning and interior work.
Avoiding Delays
- Lock material selections before work starts.
- Submit complete permit drawings the first time.
- Book licensed trades early in a busy market.
Planning a Johnston Project? Start Here.
You now have honest timelines for the most common Johnston projects and the factors that move them. The next step is a written plan from a team that knows the local process.
Busy Builders has completed 1,285+ projects across Central Iowa since 2020. We provide a written timeline upfront, coordinate the licensed trades, and keep you informed from permit to final inspection. Here is what we offer:
- Free consultation to map your project and realistic schedule
- Written timeline and estimate before work begins
- Local knowledge of Johnston permits, codes, and inspections
- Coordination of licensed electrical, plumbing, and mechanical trades
- Written warranty on workmanship (details provided in your contract)
Ready to plan your project? Contact us today:
Call: 844-435-9800
Website: https://busybuildersiowa.com/
We serve Johnston and all Central Iowa communities. Schedule your free consultation today.
Disclaimer: This article is for general information and is not project-specific advice. Timelines are planning estimates that vary by scope, site conditions, weather, permit review timing, material lead times, and decision-making speed. No specific completion date or outcome is guaranteed. Permit requirements and review times vary by city and jurisdiction; verify current requirements with the Johnston Building Department before starting any project. Consult a registered contractor for guidance specific to your project, and note that electrical, plumbing, and mechanical work must be performed by licensed subcontractors. Radon levels vary by home; test before basement or foundation work, and attribute radon statistics to the Iowa Radon Survey.
Busy Builders | Full-Service Construction and Remodeling | Serving Central Iowa Since 2020
