ADU Project Milestones: Key Phases

Building an ADU isn't easy, but understanding the process helps. Here's a quick overview of the main phases:

Planning and feasibility (1-4 weeks)
Design and engineering (12 weeks)
Permitting (16-24 weeks)
Construction (16-24 weeks)
Final inspections and occupancy (1-2 weeks)

Phase	Time	Key Activities
Planning	1-4 weeks	Property check, budget setting, builder selection
Design	12 weeks	Sketching ideas, detailing plans, engineering
Permitting	16-24 weeks	Paperwork, city review, adjustments
Construction	16-24 weeks	Site prep, building, utility hookups, finishing
Final Steps	1-2 weeks	Safety checks, final approval, move-in clearance

Remember: These timelines can vary based on your location, project complexity, and local rules. In some places like LA, streamlined ADU regulations might speed things up.

Understanding these milestones helps you:

Set realistic deadlines and budgets
Work effectively with professionals
Anticipate potential issues
Make informed decisions throughout the process

Let's dive into each phase to set you up for ADU success.

1. Getting Started

Starting an ADU project is exciting, but it needs careful planning. Let's look at the key first steps to get your ADU journey off to a good start.

Check Your Property

First, make sure your property can actually have an ADU:

Look up local zoning laws. Some states like California are ADU-friendly, but rules change by city.
Walk your land. Where could the ADU go? Think about things like setbacks and where utilities are.
Know the size limits. In California, for example, detached ADUs can be up to 1,200 square feet. Attached ones? Only up to half the size of your main house.

Set Your Budget

Money matters. Here's a rough idea of what you might spend:

What	How Much
Design and Planning	$6,000 - $14,000
City Fees	$3,000 - $11,000
Building (per sq ft)	$175 - $350
Finishing (per sq ft)	$50 - $100

These are just averages. Your actual costs might be different. For instance, in Temecula, California, a small JADU might cost about $182,000. A bigger ADU? That could be over $540,000.

Pick Your Builder

Choosing the right builder is key. Here's what to do:

Find builders who specialize in ADUs in your area.
Check their credentials and past work.
Read what other people say about them.
Get quotes from a few different builders.

"A good builder can make your ADU dream come true. Look for someone with experience and a history of finishing ADUs successfully." - Leah Kabli, Founder of TheBestADUBuilders.com

First Design Meeting

Your first meeting with the designer sets the stage for everything. Here's how to prepare:

Bring pictures of ADUs you like
Know your budget
Think about how you'll use the ADU
Ask about ways to save energy (and money)

Project Checklist

Before you go any further, make sure you've done these things:

[ ] Checked if ADUs are allowed in your area
[ ] Looked at your property to see if it works for an ADU
[ ] Set a budget you can stick to
[ ] Found a builder you trust
[ ] Thought about what you want your ADU to look like
[ ] Learned about the permits you'll need

2. Design Steps

Designing your ADU is a big deal. It's the blueprint for your entire project. Let's break it down into manageable chunks.

Building Plans

First up: creating detailed building plans. This process usually involves five stages:

Site Measurement
Schematic Design
Design Development
Construction Documents
Permit Submission

"Hire a draftsman or architect who knows ADUs inside and out, especially in your city. It's a game-changer." - Experienced General Contractor

Here's a real-world win: In Los Angeles, one homeowner's plans got the green light in just 30 days, thanks to their ADU-savvy architect.

Property Layout

Your ADU needs to play by the rules. That means following local zoning laws and building codes. Keep an eye on:

How far it needs to be from property lines
How big it can be
How tall it can be
Parking rules

For example, in California, you can build a detached ADU up to 1,200 square feet. But if you're attaching it to your main house, you're limited to 50% of the house's size.

Pick Materials

Choosing materials isn't just about looks - it's about your wallet too. Here's a rough breakdown:

Component	Slice of the Pie
Materials	45-50%
Labor	40%
Pro Fees	20-30%

Think about durability, energy efficiency, and your local weather when picking materials. Good insulation, for instance, can save you money on energy bills down the road.

Final Costs

Time to get real about numbers. Here's what different types of ADUs typically cost:

ADU Type	Price Tag
Basement makeover	$60,000–$150,000
Garage transformation	$60,000–$150,000
New attached build	$100,000–$216,000
Above-garage build	$128,000–$225,000
New detached build	$110,000–$285,000

Remember, these are ballpark figures. Your actual costs might be different based on where you live, how big your ADU is, and what design choices you make.

Design Check

Before you dive in, double-check everything. Make sure your design:

Fits within size limits
Uses approved exterior materials
Includes all required safety features

"Always call the inspector before you cover up any work. It's a simple step that can save you big headaches." - Leah Kabli, Founder of TheBestADUBuilders.com

3. Getting Permits

Getting permits for your ADU isn't a walk in the park, but it's a must-do. Here's how to tackle it:

Prepare Papers

First things first: gather these docs:

ADU Permit Application Form (filled out)
Proof you own the property
Site plans (current and future)
Detailed construction plans
Tree permit (if you're axing protected trees)

"Get your docs ready before applying. It can shave weeks off the process." - Leah Kabli, TheBestADUBuilders.com

What to Submit

Your local planning folks need:

Document	What It Is
Application Form	The whole shebang, filled out right
Site Plans	Your property now, and with the ADU
Construction Plans	Blueprints, floor plans, the works
Ownership Proof	Legal stuff showing it's your place
Fee Payment	Permit fees (usually $2,000 - $10,000)

City Review

Once you've handed it all in, here's what happens:

1. Initial look-see (1-2 weeks)

2. Department green lights (time varies)

3. Fixes and do-overs (if needed)

In L.A., things move faster. Florentine Christian from Sidekick Homes says, "We submit to LADBS, and in a few weeks, we get feedback and a list of clearances we need."

Get Your Permits

If all's good:

1. Pay up (any leftover fees)

2. Snag your approved permits

3. Set up erosion control (they'll tell you what)

4. Book your inspections

Heads up: In L.A., most ADU permits take 4-6 months. But if you're near the coast or in a special zone, it might take longer.

Rules Check

Before you start digging:

Make sure you're following zoning rules
Check you're up to code
Think about your impact on the environment
Get geohazard clearance (if you need it)

"Always ring the inspector before you cover anything up. It's a small step that can save you big time." - Avi Levi, Levi Construction

4. Building Your ADU

You've got your permits. Now it's time to build. Let's break down the process:

Prepare the Land

First, get your site ready:

Clear the area
Grade the land
Mark utility lines

"Good site prep saves you money. Don't cut corners here." - Leah Kabli, TheBestADUBuilders.com

Build Foundation

Your ADU needs a solid base:

Excavate
Install footings
Pour concrete

For an 800 sq ft ADU, this takes about 1-2 weeks.

Frame and Build

Now your ADU takes shape:

Put up wall frames
Install roof trusses
Add sheathing

Task	Time
Wall framing	3-5 days
Roof framing	2-3 days
Sheathing	2-3 days

Add Utilities

Time to wire up your ADU:

Rough-in plumbing
Install electrical
Set up HVAC

This takes about 2-3 weeks. Work closely with your contractor here.

Finish Work

The final push:

Insulation and drywall
Flooring
Cabinets and countertops
Paint
Fixtures and appliances

This takes 4-6 weeks, depending on your design.

"Build for energy efficiency. It costs more now but saves you later." - Avi Levi, Levi Construction

Don't forget: You'll need inspections throughout. Your contractor should handle this, but stay in the loop.

Building an ADU is a big job. But with a good team and prep, it can go smoothly. Keep talking to your contractor, be ready for surprises, and soon you'll have your new space.

5. Project Completion

You're almost there! Let's wrap up your ADU project and make it official.

Safety Checks

Time for the pros to give your ADU a thorough inspection:

Book your final inspection with the city
Test all systems (electrical, plumbing, HVAC)
Double-check everything matches your approved plans

"Final inspections usually take 2-4 hours. They cover everything from structure to safety features." - Leah Kabli, TheBestADUBuilders.com

Plan ahead: Prep at least two weeks before the inspection. It'll save you time and stress later.

Final Approval

Pass the inspection, and you'll get your Certificate of Occupancy (CO). Here's what you need to know:

Most cities issue the CO within two business days after you pass. Some places, like San Diego, don't give COs for single units or duplexes. Need to move in ASAP? You can ask for a Temporary CO, but it'll cost you about $410.

Last Review

Before you celebrate, do one last walkthrough:

Area	What to Check
Outside	Visible address numbers, paint job, no exposed wires
Inside	All fixtures installed, working appliances
Systems	Every outlet, switch, and faucet
Paperwork	All permits closed, fees paid

Get Your Papers

Gather these important documents:

Certificate of Occupancy (or Temporary CO)
All closed permits
Final inspection reports
Warranty info for appliances and systems

Keep these safe - you might need them if you sell or refinance later.

Ready to Move In

You're almost done! Just a few final steps:

Deep clean the entire unit
Test all locks and security features
Take photos of your finished ADU

"Document everything during construction. It'll help if questions come up during the final inspection or later." - Avi Levi, Levi Construction

Congrats! Your ADU is ready. Whether you're renting it out or moving in, enjoy your new space!

Find ADU Builders

Finding the right builder for your ADU project is key. Here's how to connect with pros who know their stuff:

Use TheBestADUBuilders.com

TheBestADUBuilders.com is a directory that hooks you up with solid ADU builders across the US. It's pretty simple:

Tell them about your project
Get matched with vetted builders
Check out builder profiles and reach out directly

"We only list builders we trust. It's all about giving homeowners confidence when picking an ADU pro." - Leah Kabli, Founder of TheBestADUBuilders.com

Grill Your Potential Builders

When you're sizing up ADU builders, hit them with these questions:

"How long have you been building ADUs?" "Got any references I can call?" "Can I see your past ADU projects?" "Are you licensed, insured, and bonded?"

These questions help you spot the pros who know their stuff and won't leave you hanging.

ADU Costs: What to Expect

ADU prices can be all over the map. Here's a rough idea:

Prefab ADUs: $80 - $160 per square foot Attached ADUs: $125 - $225 per square foot Detached ADUs: $150 - $250 per square foot (fancy ones can hit $400) Basement/Garage Conversions: $50 - $200 per square foot

But remember, these are just ballpark figures. Your actual costs? They'll depend on where you live, what materials you use, and how fancy you want to get.

Double-Check Those Credentials

Before you sign anything:

Look up the builder's license
Scope out online reviews (GreatBuildz, Houzz, BuildZoom)
Ask to see their insurance and bonding paperwork

Local Know-How is Crucial

ADU rules change from city to city and state to state. Pick a builder who knows your local laws inside and out. For example, in LA, ADU permits usually take 4-6 months. But if you're near the coast? Might take longer.

Next Steps

Ready to turn your ADU dream into reality? Here's what you need to do:

Research Local Regulations

First things first: get to know your city's ADU rules. They're different everywhere, so this step is crucial.

"The first step in building an ADU is to research the accessory dwelling unit ordinance in your city. Regulations can differ significantly from one area to another." - Leah Kabli, Founder of TheBestADUBuilders.com

Look into size limits, owner occupancy rules, setbacks, zoning, parking, and the permit process.

Crunch the Numbers

Time to talk money. Here's a quick look at potential costs:

ADU Type	Estimated Cost Range
Prefab	$80 - $160 per sq ft
Attached	$125 - $225 per sq ft
Detached	$150 - $250 per sq ft
Conversions	$50 - $200 per sq ft

Keep in mind, these are just estimates. Your actual costs will depend on where you live, what materials you use, and your design choices.

Secure Financing

Get pre-approved for financing. You've got options:

Cash
Home Equity Line of Credit (HELOC)
Construction loans

This step makes sure your budget matches your project goals.

Consult with Professionals

Don't try to do this alone. Work with experts who know their stuff:

1. Architect or Designer: They'll create plans that meet local codes and your needs.

2. ADU Contractor: Find someone with ADU-specific experience.

"Hiring a designer with experience in ADUs can save time, money, and disappointment." - Maxable Team

Submit Plans and Get Permits

Work with your team to prepare detailed plans and submit them to your local department of building and safety. Be ready for revisions - this process can take months, so start early.

Manage Construction

Got the green light? Great! Now it's time to:

Prep the site
Oversee foundation work
Monitor framing and utility installation
Make sure inspections happen regularly

Final Touches and Occupancy

You're in the home stretch! Here's what's left:

Schedule final inspections
Get your Certificate of Occupancy
Add those finishing touches to make your ADU feel like home

And there you have it - your roadmap to ADU success. Remember, each step is important, so take your time and do it right. Before you know it, you'll be enjoying your brand new ADU!

FAQs

What is the first step to build an ADU?

The first step to build an ADU? Research. You need to understand your local zoning rules and property requirements. It's not the most exciting part, but it's crucial.

Here's why: In California, the ADU permit process can take 1 to 6 months. That's a big range. The difference? Often it's how well you've done your homework.

A seasoned ADU builder once told me: "I've seen people get tangled up in red tape." Don't let that be you.

Here's what you need to do:

Check your local zoning laws and property size
Make sure you meet ADU requirements
Get a soils report if needed

But don't stop there. Dig into your county's specific zoning rules. Team up with a local ADU expert. They've been through this before and can guide you.

Oh, and don't forget about water. Contact your water company early for the water flow letter. It's a small step that can save you big headaches later.

Bottom line? Do your research. It might not be fun, but it'll save you time and money in the long run.