Yes, you can build an ADU in Coeur d’Alene. The city has allowed accessory dwelling units on residential lots since 2007, and a new state law taking effect July 1, 2026 is about to expand what CDA homeowners can build. If you’ve been thinking about adding a backyard cottage, an in-law suite, or a rental unit on your property, 2026 is a genuinely good time to move forward.
This guide covers Coeur d’Alene’s current ADU rules, what’s changing under Idaho’s SB 1354, whether your property qualifies, and what the permit process actually looks like. Rules are in transition right now, so we’ll be clear about what applies today versus what changes in July.
| Heads Up: Rules Are Changing July 1, 2026
Coeur d’Alene’s current ADU code has been in place since 2019. Idaho’s new SB 1354 takes effect July 1, 2026 and overrides some of those local rules. Cities have until February 1, 2027 to update their codes. This article explains both the current rules and what changes. Always verify current requirements with the City of Coeur d’Alene Planning Department at (208) 769-2274 before you apply. |
Does Coeur d’Alene Allow Detached ADUs?
Yes. CDA has allowed detached ADUs on residential lots for years. The city’s code permits you to build a completely separate structure in your backyard as long as there’s only one single-family home on the property and your project meets the size, setback, height, parking, and lot coverage requirements.
Coeur d’Alene handles ADU permits through a by-right process, which means you don’t have to go through a public hearing or a discretionary review. If your project meets the standards, it gets approved administratively. That’s a meaningful advantage compared to cities that force ADU applicants through lengthy approval processes.
The city even offers free pre-approved ADU plan sets, developed through the Housing Solutions Partnership and reviewed by local building officials and planners. These are available to any property owner in Kootenai County and can save you significant design fees and speed up your permit review.
Current CDA ADU Rules (Before July 1, 2026)
Here’s a summary of Coeur d’Alene’s current ADU standards as they stand before SB 1354 takes effect. Some of these rules will change after July 1, 2026, which we’ll address in the next section.
| Requirement | Current CDA Rule | Changes After July 1? |
| Maximum size | 800 sq ft or 75% of primary home, whichever is less | Yes. New minimum rises to 1,000 sq ft under SB 1354 |
| Minimum size | No minimum | No change |
| Side setback | 5 ft minimum from side lot line | Subject to SB 1354 parity rule |
| Height (1-story) | 18 ft maximum | Subject to SB 1354 parity rule |
| Height (above garage) | 24 ft maximum; 2nd story step back required | Subject to SB 1354 parity rule |
| Parking | 3 paved stalls total: 1 for ADU, 2 for primary home | Likely changes; SB 1354 restricts parking mandates |
| Lot coverage | 30% of the lot must remain pervious surface | No direct change from SB 1354 |
| Owner occupancy | Required if either unit is used as short-term rental | SB 1354 prohibits owner-occupancy mandates for long-term rental |
| Placement | Rear yard required for detached units | No change; SB 1354 also requires rear yard placement |
Size: Currently Capped at 800 Square Feet
Under current code, your detached ADU can be no larger than 800 square feet of finished living space, or 75% of your primary home’s floor area, whichever number is smaller. Unfinished basement space doesn’t count toward the square footage calculation.
This is actually one of the most restrictive size caps of any major Idaho city, and it’s about to conflict directly with SB 1354. The new state law sets a minimum protected ADU size of 1,000 square feet. CDA’s current 800 sq ft cap is below that floor, which means the city will need to update its code by February 1, 2027.
Setbacks: 5 Feet on the Sides
Detached ADUs need at least 5 feet of clearance from each side property line. This is the current code standard following the 2019 amendments, which removed an older 3-foot allowance. Your ADU also needs to be placed in the rear yard.
For rear setbacks, check your specific zoning district. CDA’s setback rules vary by zone. The Planning Department at (208) 769-2274 can confirm the rear setback requirement for your address.
Height Limits
Single-story detached ADUs top out at 18 feet. If you want to build an ADU above a detached garage, the maximum height is 24 feet, but second-story units also have to meet CDA’s step-back requirement. The step back creates an air space buffer between the upper level of your ADU and the neighboring property. Your building permit submittal needs to show all step-back dimensions.
Parking: Three Paved Stalls Required
This is one of the more significant local requirements to plan for. Adding an ADU to your property triggers a requirement for three total paved parking stalls: two for the primary home (each 9 by 20 feet) and one for the ADU (also 9 by 20 feet). If your property doesn’t currently have two paved stalls for the main house, you’ll need to add those as part of the project.
SB 1354 restricts cities from requiring parking for ADUs in most situations, so this requirement is likely to change after July 1, 2026. But right now, under current code, three paved stalls is the standard.
Pervious Surface: 30% of Your Lot
Adding a structure and parking adds impervious surface. CDA requires that at least 30% of your lot remain pervious surface after the ADU is built. Pervious surface includes grass, gravel, pavers, decking (without impervious material underneath), and similar materials. Your permit submittal needs to include a calculation showing pervious coverage across the full lot.
Owner Occupancy and Short-Term Rentals
Under current CDA code, if you want to use either the primary home or the ADU as a short-term rental (less than 30 days), a majority owner of the property must occupy one of the units. You can’t rent out both as short-term rentals. If you’re planning a long-term rental, this restriction doesn’t apply under the rules that take effect with SB 1354, which prohibits cities from requiring owner-occupancy at all.
If short-term rental is part of your plan, you’ll also need to comply with CDA’s short-term rental requirements in Chapter 17.08, Article X of Title 17 of the city code.
What Changes After July 1, 2026
Idaho’s SB 1354 takes effect July 1, 2026. Coeur d’Alene is a city well above the 10,000 population threshold the law covers, so it applies. Cities then have until February 1, 2027 to update their local codes. Here’s what that means for CDA homeowners in practical terms.
| CDA Has Expressed Frustration With SB 1354
At a May 2026 workshop, Coeur d’Alene City Council and Planning Commission members reviewed SB 1354 and used pointed language about the loss of local control. Planning Director Hillary Patterson confirmed that ADU rules in CDA will look different after July 1. The law passed regardless, and CDA must comply. The city’s frustration is real, but so is the compliance obligation. |
Size Minimum Rises to 1,000 Square Feet
This is the biggest concrete change for CDA homeowners. CDA’s current 800 sq ft cap conflicts with SB 1354’s requirement that cities allow ADUs of at least 1,000 square feet. Once the law takes effect, CDA can’t enforce the 800 sq ft limit. The protected minimum becomes 1,000 sq ft.
The full SB 1354 size formula: cities can’t require your ADU to be smaller than 1,000 sq ft, or smaller than 75% of your primary home’s square footage, whichever of those numbers is larger. So if you have a 1,600 sq ft home, your protected minimum is 1,200 sq ft (75% of 1,600). The 1,000 sq ft floor is the baseline.
Owner-Occupancy Restrictions Come Off for Long-Term Rentals
SB 1354 prohibits cities from requiring owner-occupancy for long-term rentals. After July 1, 2026, you can rent your ADU as a long-term rental without living on the property. Short-term rental rules are separate and still governed by local ordinance.
Parking Requirements Are Likely to Ease
SB 1354 restricts cities from requiring off-street parking for ADUs in most cases. CDA’s current three-stall requirement is one of those restrictions the law is designed to limit. The exact picture will depend on how CDA writes its updated code, but expect the parking mandate to look different after February 2027.
Height and Setbacks: Parity With Single-Family Homes
Under SB 1354, ADU setbacks and height limits can’t be more restrictive than what the city applies to single-family homes in the same zone. CDA can’t set lower height limits or tighter setbacks for ADUs than it does for regular houses. The rear-yard placement requirement stays, since that’s written into the state law itself.
What this looks like in practice will depend on how CDA rewrites its code. The city has until February 1, 2027. Until then, verify current requirements directly with the Planning Department before submitting.
Does Your Property Qualify?
Before you start planning a project, here are the key eligibility questions to work through.
Are You Inside City Limits?
CDA’s ADU rules only apply to properties within Coeur d’Alene city limits. Some properties have a CDA mailing address but actually sit in unincorporated Kootenai County jurisdiction. Your mailing address and your zoning jurisdiction aren’t necessarily the same thing. If you’re not sure, call the Planning Department or check your parcel at the Kootenai County assessor’s website.
| Unincorporated Kootenai County Is a Different Set of Rules
If your property is outside CDA city limits, SB 1354 and CDA’s ADU code don’t apply to you. Kootenai County has its own ADU rules for unincorporated land. Contact Kootenai County Planning and Zoning to find out what you can build. |
Is Your Property Single-Family?
CDA’s ADU rules apply to single-family residential lots with one detached home on the property. If your lot already has more than one dwelling unit, or isn’t zoned for single-family use, check with the Planning Department before assuming an ADU is allowed.
Is There Room in the Rear Yard?
Detached ADUs have to go in the rear yard with the required setbacks. Pull out your property survey and look at what you’ve actually got to work with. You need at least 5 feet from each side property line and you’ll need to factor in the rear setback for your zone. Then consider the parking requirement (currently three paved stalls) and the 30% pervious surface rule. A lot of the planning work is just confirming the geometry works.
Do You Have a Historic Property Designation?
Properties designated under Idaho Code Sections 67-4607 or 67-4614 as part of a historic district are exempt from SB 1354’s requirements. If your property is on a historic register, confirm your specific situation with the Planning Department. CDA has a Historic Preservation Commission that may have additional involvement in your project.
How to Get an ADU Permit in Coeur d’Alene
CDA handles ADU permits through Building Services (208-769-2267) and the Planning Department (208-769-2274). Here’s the general process.
Step 1: Start With a Pre-Development Meeting
The city strongly recommends scheduling a free pre-development meeting with staff before you submit anything. This is genuinely useful, not just bureaucratic box-checking. Staff can tell you exactly what setbacks apply to your lot, flag any site-specific issues, and confirm whether the free pre-approved plan sets would work for your project. It often results in a faster approval.
Step 2: Decide on Plans
You have two main options for plans. First, you can use one of the free pre-approved ADU plan sets available through Housing Solutions Partnership. These plans (all 800 sq ft and under) have already been reviewed by building officials and planners, so the plan review portion of your permit process is streamlined. Second, you can hire your own architect, home designer, or engineer to produce custom plans. Custom plans cost more and take longer to review, but give you more flexibility on size, layout, and design.
Note: With SB 1354 raising the minimum protected size to 1,000 sq ft, the pre-approved plans are all technically below the new state minimum. You may want to discuss this with the Planning Department if you want to build larger than 800 sq ft after July 1, 2026.
Step 3: Assemble Your Permit Application
Your ADU permit application in CDA needs to include:
- City of Coeur d’Alene Building Application
- ADU Application form (includes owner affidavit)
- Scaled site plan showing the lot, existing structures, proposed ADU, setbacks, and parking
- Lot coverage and pervious surface calculation
- Truss, floor joist, header, and beam information
- HVAC information
- Stamped engineering plans if using custom design
The site plan and lot coverage plan are not included in the pre-approved plan sets, so you’ll need to produce those separately regardless of which plan option you choose.
Step 4: Submit and Wait for Review
ADU permits in CDA go through an administrative review process, not a public hearing. The review timeline depends on staff workload and how complete your application is when you submit. If you’re using a pre-approved plan set, the review is typically faster since the structural plans have already been vetted.
Step 5: Record the Required Document
Once your permit is approved and the ADU is built, CDA requires you to record a document with the Kootenai County Recorder that identifies the property address, confirms an ADU is located on the property, and states that you’ll notify future buyers of the ADU’s status. This recording runs with the land, which means it stays with the property even if you sell.
What Kind of ADU Makes Sense in Coeur d’Alene?
Coeur d’Alene’s lot sizes vary significantly by neighborhood. Older neighborhoods closer to downtown tend to have smaller lots where fitting a detached structure and meeting the parking and pervious surface requirements takes more careful planning. Newer subdivisions on the north side of the city often have more room to work with.
The most common configurations CDA homeowners are building or considering:
Standalone Backyard Cottage
A completely separate structure with its own entrance, kitchen, bathroom, and bedroom. Works well on lots with enough rear yard space to meet setbacks and leave room for parking. Currently capped at 800 sq ft; rising to a minimum of 1,000 sq ft under SB 1354 after July 1.
ADU Above a Detached Garage
One of the most efficient configurations for smaller lots: you use the garage footprint for living space above while keeping the car storage below. CDA specifically updated its code in 2019 to allow this configuration. The second-story step-back requirement applies, so factor that into your design.
Converted Existing Garage or Shed
CDA allows existing detached garages and sheds to be converted to an ADU, provided the structure can meet current building codes. This is often the most cost-effective path if you already have a structure with the right footprint. The converted structure still needs to meet size, setback, and height requirements, and needs to comply with building, plumbing, electrical, and mechanical codes.
Building Your ADU: Where Kit Culture Fits In
If you’re a CDA homeowner who’s ready to move forward on a backyard ADU, Kit Culture is worth a look. We’re an Idaho-made kit home company built on the same manufacturing platform as Metal America, and we’re developing ADU-specific models designed for exactly this use case.
Every Kit Culture home ships permit-ready on a single truck. Pre-cut framing components, engineered drawings stamped for Idaho, and a complete package of premium finishes are all included: LG appliances, quartz countertops, Milgard windows, a multi-zone ductless heat pump, LVP flooring, and a 40-year metal roof and siding system. There are no material sourcing surprises and no builder allowance games.
The price point is genuinely different from anything else available in this market. A traditional custom-built detached ADU in the Coeur d’Alene area typically costs $180,000 to $300,000 or more. Kit Culture ADU models come in at roughly half that, without cutting corners on the finish level. That pricing difference is possible because manufacturing components at scale in a controlled facility is a fundamentally more efficient process than coordinating a custom build from scratch on your property.
Build time is also dramatically faster. Most Kit Culture homes are weather-tight within days of delivery and fully move-in ready in under 90 days.
| Kit Culture ADU Models Coming in 2026
We’re developing three ADU-specific models designed for detached backyard placement, priced between $69,000 and $75,000 depending on size and options. Made in Idaho, shipped permit-ready, and backed by a strong warranty. |
Kit Culture sells direct to homeowners. If you’d rather have a licensed general contractor manage the build, our contractor pricing program gives local GCs trade pricing so they can make money on the project while you still pay well under a custom build. Your contractor handles the site prep and local permitting. Kit Culture handles everything that arrives on the truck.
| Want to See What’s Possible on Your CDA Property?
Our team is based right here in North Idaho and knows the local market well. If you’re ready to explore your ADU options in Coeur d’Alene, we’d love to talk. Give us a call. We can walk you through the models, the process, and what it would realistically look like on your lot. |
Frequently Asked Questions
Are ADUs allowed in Coeur d’Alene?
Yes. CDA has allowed ADUs on single-family residential lots since 2007. Detached backyard structures are permitted as long as your project meets the size, setback, height, parking, and lot coverage requirements. The permit process is administrative, meaning you don’t need a public hearing.
How big can my ADU be right now?
Under current CDA code (before July 1, 2026), the maximum is 800 sq ft of finished living space, or 75% of your primary home’s floor area, whichever is smaller. After July 1, 2026, SB 1354 raises the protected minimum to 1,000 sq ft, which directly conflicts with CDA’s current cap. The city will need to update its code by February 1, 2027.
What setbacks apply to a detached ADU in CDA?
Currently, detached ADUs need at least 5 feet from each side property line. Rear setback varies by zoning district. Your ADU must be located in the rear yard. After July 1, 2026, SB 1354 requires that setbacks for ADUs be no more restrictive than setbacks for single-family homes in the same zone.
Do I need extra parking for an ADU in Coeur d’Alene?
Under the current code, yes. Adding an ADU requires three total paved parking stalls: two for the primary home and one for the ADU, each 9 by 20 feet. This is one of the requirements that’s likely to change after July 1, 2026, when SB 1354 restricts parking mandates for ADUs in most situations.
Can I rent my ADU out in Coeur d’Alene?
Yes, for long-term rentals. SB 1354, which takes effect July 1, 2026, prohibits cities from requiring owner-occupancy for long-term rentals. For short-term rentals (under 30 days), CDA requires that a majority owner occupy one of the units on the property, and you’ll need to comply with CDA’s short-term rental ordinance.
What are the free ADU plans I’ve heard about?
The Housing Solutions Partnership and local building officials developed four pre-approved ADU plan sets that are free to use anywhere in Kootenai County. These plans are 800 sq ft and under and have already been reviewed, which can speed up your permit process. You can find them through the City of Coeur d’Alene Planning Department or at cdaid.org.
Can I convert an existing garage into an ADU?
Yes. CDA allows conversion of existing detached garages and sheds to ADUs if the structure can meet current building codes. You’ll still need to satisfy size, setback, height, parking, and lot coverage requirements, and the converted structure needs to comply with building, plumbing, electrical, and mechanical codes.
My property is outside CDA city limits but has a CDA address. Do these rules apply to me?
Not necessarily. Your mailing address and your zoning jurisdiction can be different things. If your parcel is in unincorporated Kootenai County, CDA’s ADU code and SB 1354 don’t apply. Contact Kootenai County Planning and Zoning to understand your options.
How much does it cost to build an ADU in Coeur d’Alene?
Traditional custom-built detached ADUs in the CDA area typically cost between $180,000 and $300,000 or more depending on size, site conditions, and finish level. A kit-built ADU from Kit Culture comes in at roughly half that cost with premium finishes already included. Our ADU models are priced between $69,000 and $75,000 depending on size and options.
Who do I contact at the City of Coeur d’Alene for ADU questions?
Planning Department: (208) 769-2274. Building Services: (208) 769-2267. You can also visit cdaid.org for current applications, fee schedules, and the free pre-approved ADU plan sets. A pre-development meeting with staff is free and genuinely worth scheduling before you submit.
