Permits and Approvals: The ADU Process Timeline

# Permits and Approvals: The ADU Process Timeline

Here's the truth about ADU permits: Most homeowners get approved. The timeline is usually 2-6 months, not years. And you don't need to become a permit expert - your builder or designer handles most of the complicated parts. Yes, it's a process with real steps and waiting periods, but it's a process thousands of regular homeowners complete successfully every year.

The reason permits feel intimidating is because you're hearing the horror stories, not the typical experiences. Let's walk through what actually happens for most people.

## The Real Timeline (Not the Nightmare Version)

**Pre-design (2-4 weeks):**
This is when you check local ADU rules and confirm your property qualifies. Many cities now have online checkers or ADU-specific staff who can tell you in 10 minutes if your lot works. Some homeowners do this themselves, others have builders do it during the first consultation.

**Design and plan prep (4-8 weeks):**
Your designer or builder creates plans that meet local codes. If you're using a modular company with pre-approved plans, this goes faster. Custom stick-built designs take longer but let you get exactly what you want.

**Permit submission to approval (2-6 months):**
This is the waiting part. The city reviews your plans, sometimes asks for minor revisions, then approves. Timeline varies wildly by city:
- Streamlined cities (Portland, San Diego, Seattle): 1-3 months
- Average cities: 3-4 months
- Slower cities or complex designs: 4-6 months

**Real homeowner timeline:**
"We submitted in March, got comments in May asking for a drainage plan tweak, resubmitted in a week, and got approved in June. Total was 3.5 months. Our builder said that was typical." - Denver homeowner

## What Cities Actually Look For

You're not trying to sneak something past the city - you're showing them your ADU meets safety and zoning rules. Here's what they check:

**Setbacks:** How far from property lines (usually 5-10 feet)
**Height:** Maximum height limit (often 16-25 feet)
**Lot coverage:** Percentage of your lot you can build on
**Parking:** Some cities require one space, many have dropped this requirement
**Utilities:** Electrical, plumbing, and sewage connections meet code
**Fire safety:** Smoke detectors, egress windows, proper ventilation

Here's what homeowners worry about but rarely causes problems: Architectural style, interior layout choices, your specific use case (rental vs family), what you plan to charge for rent.

Cities care about safety and zoning compliance, not whether your kitchen is pretty or who's living there.

## The Part That Actually Takes Time

It's not that permits are complicated - it's that cities have backlogs. Your application sits in a queue. When it reaches the front, the review itself takes days or weeks, not months.

**Good news:** Many cities now have ADU "fast track" programs. Submit complete plans that follow clear guidelines, and you jump ahead in line. Some cities approve simple ADUs in 30-60 days through these programs.

**How homeowners speed things up:**
- Use builders familiar with local requirements (they know exactly what the city wants)
- Submit complete applications (missing documents restart the clock)
- Choose standard designs over highly custom ones
- Respond quickly to any city questions or revision requests
- Take advantage of pre-approved plan programs where available

## What If You Get Rejected or Need Revisions?

Most "rejections" are actually revision requests. The city says "adjust this setback" or "add this electrical detail" - you fix it, resubmit, and get approved. True rejections (you can't build an ADU at all) are rare and usually happen because of fundamental zoning issues you should catch in pre-design.

**Real homeowner experience:**
"The city came back asking us to move the ADU 2 feet further from the side property line. We adjusted the plans, resubmitted, approved two weeks later. Our builder said 'this is normal' and he was right." - Sacramento homeowner

Only about 5-10% of ADU applications face significant obstacles, and most of those are on properties with unusual constraints that surface during the pre-design phase.

## Do You Need to Notify Neighbors?

Depends on your city. Some require neighbor notification, some don't. When notification is required, it's usually a letter saying "we're planning to build an ADU, here's what it looks like."

**Reality check:** Most neighbors don't object. They're often curious or supportive. The nightmare neighbor who blocks your project? That's rare, and even when neighbors do object, cities rarely deny permits unless there's a legitimate zoning violation.

Many homeowners worry about this for months and then their neighbor says "oh cool, we've been thinking about doing one too."

## The Inspection Process During Construction

Once permitted, you'll have inspections at key milestones:
- Foundation inspection (before pouring concrete)
- Framing inspection (before closing walls)
- Rough-in inspections (electrical, plumbing before drywall)
- Final inspection (everything complete)

**Your builder handles:** Scheduling inspections, being on-site during inspections, addressing any inspector comments

**You handle:** Not much. Maybe be available if inspector needs property access and builder isn't there.

Failed inspections sound scary but are usually minor: "Add a nail here" or "Label this wire." Builders fix and inspector returns within days.

## What This Actually Costs

**Permit fees:** $2,000-$8,000 depending on city and ADU size (based on valuation of construction)

**Plan preparation:** $3,000-$8,000 if hiring a designer separately (often included in builder's quote)

**Utility connection fees:** $2,000-$10,000 depending on city (some cities charge "impact fees" to connect to water/sewer)

**Total permit-related costs:** $7,000-$26,000 typically

These aren't trivial costs, but they're also not the biggest part of your ADU budget (which is the construction itself). And they're one-time expenses that unlock an asset worth $100,000-$200,000+.

Many builders include permit fees and plan prep in their total quote, so you're not writing separate checks for everything. Ask upfront what's included.

## City-Specific Considerations

**California cities:** Generally have the most streamlined ADU laws thanks to state legislation. Pre-approved plans available. Fast-track programs common. Owner-occupancy requirements eliminated statewide in 2020.

**Portland, Oregon:** Pioneer in ADU-friendly policy. Experienced building department, clear guidelines, reasonable timelines.

**Seattle, Washington:** DADU (detached ADU) and AADU (attached ADU) programs well-established. Lots of pre-approved plans. Good city resources.

**Texas cities:** Newer to ADU-specific regulations. Austin leads. Other cities catching up. Less established processes but improving rapidly.

**East Coast cities:** Varies wildly. Some cities very ADU-friendly, others still working out regulations. Boston, Philadelphia have active ADU markets.

## Your Builder Does Most of This

Here's what surprises people: You're not navigating permits alone.

**Your builder or designer typically handles:**
- Creating plans that meet local codes
- Submitting permit applications
- Responding to city questions
- Coordinating inspections during construction
- Final approval and certificate of occupancy

**You typically handle:**
- Deciding what you want to build
- Signing applications and documents
- Paying fees
- Checking in on progress

Think of permits like financing a house - yes, there's paperwork and approval processes, but you have professionals managing most of it.

## The "What If" Scenarios

**What if my property doesn't qualify?**
This surfaces in pre-design. Reasons: lot too small, existing house already maxed out lot coverage, environmental overlay zones, historic district restrictions. Your builder will tell you upfront.

**What if rules change while I'm building?**
Once permitted, you're typically grandfathered under those rules even if city changes ADU regulations later.

**What if I want to change plans mid-construction?**
Minor changes often don't need re-permitting. Major changes (bigger footprint, different configuration) require amended permits and delay construction.

**What if inspector fails an inspection?**
Builder fixes the issue, inspector returns, construction continues. Typical delay: 1-2 weeks for minor items.

## What You Should Do Right Now

The permit process isn't the thing that should stop you from exploring ADUs. It's a real step with a real timeline, but it's a manageable step that thousands of homeowners complete every year.

**Best first move:** Check if your property qualifies for an ADU [property checker link]. This tells you upfront if there are any zoning issues that would complicate permits.

**Then:** Talk to local builders who know your city's process [builder directory link]. Ask them "what's the typical timeline for permits here?" and "do you handle the permit applications?" Most will walk you through exactly what to expect in your specific city.

The homeowners who stress least about permits? They choose builders who've done 20+ ADUs in their city and already know what the planning department wants. The builder's experience becomes your shortcut.

You're in the smart phase - researching before committing. The permit timeline is just one factor in your decision, and now you know it's measured in months, not years, and managed largely by professionals you'll hire.

Most ADU homeowners look back and say "the permit wait felt long at the time, but once we were building it went fast, and now we can't imagine not having done it."