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You already know you want an ADU. The question burning a hole in your planning spreadsheet is simpler: what's it going to cost?
The frustrating truth is that "it depends" — but that answer doesn't help anyone budget. So we pulled real 2026 pricing data, talked to builders across the country, and broke down exactly what each ADU type costs, where the money goes, and where most homeowners blow their budget without realizing it.
Whether you're converting a garage, adding a prefab unit to your backyard, or building a detached cottage from scratch, this guide gives you the numbers you actually need. Not vague ranges. Not 2022 data dressed up with a new year in the headline. Real pricing for what ADU construction costs right now, in 2026.
If you want the broader overview first, check out our complete ADU cost breakdown which covers general pricing. This guide goes deeper — breaking costs down by ADU type so you can compare apples to apples.
Garage Conversion ADU: The Budget-Friendly Starting Point
Converting an existing garage into a livable ADU is consistently the cheapest path because the bones are already there. You've got walls, a roof, and a foundation. What you're paying for is the transformation: insulation, drywall, flooring, plumbing, electrical, HVAC, and code compliance.
What Garage Conversions Actually Cost in 2026
| Garage Size | Square Footage | Typical Cost Range | Cost Per Sq Ft |
|---|---|---|---|
| One-car garage | 200–400 sq ft | $36,000–$96,000 | $150–$280 |
| Two-car garage | 400–600 sq ft | $80,000–$150,000 | $175–$300 |
| Three-car garage | 600–800 sq ft | $100,000–$225,000 | $165–$310 |
A two-car garage conversion hitting the $80,000–$150,000 range is the sweet spot most homeowners land on. According to Angi's 2026 cost data, garage conversions average between $150 and $400 per square foot depending on the scope of structural work required.
Hidden Costs That Catch People Off Guard
The sticker price for a garage conversion sounds great until you realize the garage wasn't built to be lived in. Common surprises include:
- Foundation upgrades: Garage slabs are typically thinner than residential foundations. Reinforcing or re-pouring can add $5,000–$15,000.
- Ceiling height compliance: Many garages have ceilings below the 7.5-foot minimum required by building codes. Lowering the floor (underpinning) can cost $10,000–$25,000.
- Sewer/water line extensions: Running plumbing to a kitchen and bathroom from the main house's existing lines costs $5,000–$15,000 depending on distance.
- Parking replacement: Some municipalities require you to replace the lost parking space, which can mean adding a carport or driveway extension ($3,000–$8,000).
- Window requirements: Building codes mandate minimum window sizes for bedrooms (egress windows). If your garage has small or no windows, cutting into masonry walls costs $2,000–$5,000 per opening.
Despite these extras, a garage conversion is still roughly 40–60% cheaper than building a new detached ADU of similar size. You're reusing the most expensive parts — the structure and the foundation — and focusing your budget on livability. If your existing garage is in decent shape and you don't need the parking, this is the clear value play.
Attached ADU: Expanding Your Existing Footprint
An attached ADU shares at least one wall with your primary residence. This category covers two very different scenarios: interior conversions (basements, bonus rooms, unused wings) and new additions built onto your home.
Interior Conversion Costs
If you've got an unfinished basement, a large bonus room over the garage, or an underused section of your home, converting it into a separate living unit is the second-cheapest ADU option after a garage conversion.
| Conversion Type | Typical Size | Cost Range | Cost Per Sq Ft |
|---|---|---|---|
| Basement conversion | 500–1,000 sq ft | $50,000–$120,000 | $100–$175 |
| Bonus room / attic conversion | 300–600 sq ft | $40,000–$95,000 | $130–$200 |
| Wing separation (add kitchen + bath) | 400–800 sq ft | $60,000–$130,000 | $140–$190 |
Interior conversions benefit from existing utility connections. Plumbing, electrical, and HVAC are already running through the house — you're branching off, not starting from scratch. That saves $15,000–$30,000 compared to building something freestanding.
The trade-off is privacy. Shared walls mean shared noise. Most attached ADUs work best for family members rather than market-rate tenants, who generally prefer the independence of a detached unit.
New Addition Costs
Building a new attached structure is essentially new construction that happens to connect to your house. It's more complex than a standalone build because you're tying into an existing structure, which means matching roof lines, ensuring structural compatibility, and coordinating utility connections.
| Addition Size | Cost Range | Cost Per Sq Ft |
|---|---|---|
| Small (400–600 sq ft) | $120,000–$200,000 | $250–$350 |
| Medium (600–800 sq ft) | $175,000–$275,000 | $270–$360 |
| Large (800–1,200 sq ft) | $225,000–$360,000 | $275–$380 |
New attached additions typically cost 10–20% more per square foot than detached ADUs of the same size. Why? Because integrating with an existing building is structurally more complex. Your contractor has to cut into the existing wall, tie new framing to old framing, and ensure the shared wall meets fire separation requirements (usually one-hour fire rating).
According to the California Construction Cost Index, which tracks building costs in the most active ADU market in the country, construction costs have increased 44% since 2021. That means an attached addition that cost $200,000 four years ago now runs closer to $288,000 in California markets. Other states have seen more modest increases of 15–25%, but the trend is consistently upward.
The upside: attached ADUs can share HVAC systems, water heaters, and electrical panels with the main house, reducing long-term operating costs. If your goal is housing a family member who wants proximity but independence — an aging parent, an adult child — attached ADUs hit the right balance.
Detached ADU (New Construction): Maximum Flexibility, Maximum Cost
A freestanding backyard unit built from the ground up is the gold standard for ADUs — and the most expensive option. You're building an entire structure: foundation, framing, roofing, utilities, everything. But you're also getting the most versatile product. Detached ADUs pull the highest rents, add the most property value, and give both parties (homeowner and occupant) genuine privacy.
2026 Pricing by Size
| Unit Type | Square Footage | Cost Range | Cost Per Sq Ft |
|---|---|---|---|
| Studio | 300–450 sq ft | $75,000–$145,000 | $250–$325 |
| One-bedroom | 450–650 sq ft | $115,000–$215,000 | $255–$335 |
| Large one-bedroom | 650–850 sq ft | $170,000–$285,000 | $260–$340 |
| Two-bedroom | 850–1,200 sq ft | $225,000–$380,000 | $265–$350 |
In high-cost markets like Los Angeles, San Francisco, and Seattle, detached ADUs consistently land on the upper end. A mid-range detached ADU in LA — roughly 1,000–1,200 square feet, two bedrooms — typically budgets at $300,000–$380,000 according to 2026 pricing data from LA construction consultants. Companies like US Modular Inc have been active in this space, offering both modular and stick-built options to manage costs.
What Drives Detached ADU Costs Up
Several factors push detached builds toward the top of the range:
- Site preparation: Grading, soil testing, tree removal, and retaining walls can add $5,000–$30,000 before a single board is nailed. Sloped lots are especially expensive — hillside foundations can cost 2–3x a flat-lot slab.
- Utility trenching: Running sewer, water, electrical, and gas lines from the main house to a freestanding structure typically costs $8,000–$25,000, depending on distance and terrain. Every additional foot of trenching adds roughly $50–$100.
- Separate systems: Unlike attached ADUs, detached units usually need their own HVAC system ($5,000–$15,000), water heater ($2,000–$5,000), and potentially a sub-panel for electrical ($2,000–$4,000).
- Landscaping restoration: Construction equipment tears up your yard. Budget $3,000–$10,000 to restore landscaping, add a pathway, and create a functional outdoor space between the main house and ADU.
- Accessibility requirements: Some jurisdictions require ADA-compliant pathways from the street to the ADU. This can mean adding a paved walkway, ramp, or widened gate ($2,000–$8,000).
When Detached Makes Financial Sense
Despite the higher upfront cost, detached ADUs often deliver the best return on investment. They typically rent for 15–25% more than attached units of comparable size because tenants value the separation. In markets like Portland, Austin, and the Bay Area, a well-built one-bedroom detached ADU can generate $1,800–$3,200/month in rental income.
If you're weighing your options, our ADU vs. tiny home comparison breaks down how detached ADUs stack up against tiny homes on wheels — which look cheaper upfront but come with their own complications.
Prefab and Modular ADUs: The Speed-for-Cost Trade-off
Factory-built ADUs have become one of the fastest-growing segments of the market. The pitch is compelling: shorter timelines, more predictable pricing, and (sometimes) lower costs. But "prefab" covers a wide range — from basic shipping container conversions to high-end modular homes that look indistinguishable from custom construction.
2026 Prefab ADU Pricing
| Prefab Category | Size Range | Unit Cost | Total Installed Cost |
|---|---|---|---|
| Basic / economy prefab | 300–500 sq ft | $50,000–$90,000 | $110,000–$170,000 |
| Mid-range prefab | 500–750 sq ft | $80,000–$140,000 | $160,000–$250,000 |
| Premium prefab | 750–1,200 sq ft | $120,000–$200,000 | $220,000–$350,000 |
| Luxury / custom modular | 800–1,200 sq ft | $150,000–$250,000 | $280,000–$400,000 |
The critical distinction here is unit cost vs. total installed cost. The price you see advertised for a prefab ADU is almost always just the unit — the box itself, manufactured in a factory. Getting that box onto your property and making it livable adds 40–80% on top:
- Site preparation and foundation: $10,000–$30,000
- Delivery and crane placement: $5,000–$15,000
- Utility connections (sewer, water, electrical, gas): $10,000–$25,000
- Permits and inspections: $3,000–$15,000
- Finish work and touch-ups: $5,000–$15,000
- Landscaping and pathways: $3,000–$10,000
Companies like Villa Homes have worked to simplify this process with all-inclusive pricing that bundles the unit, installation, permits, and utility connections into a single quote. This transparency helps homeowners avoid the sticker-shock gap between advertised and actual costs.
Prefab vs. Stick-Built: A Realistic Comparison
The narrative that prefab is always cheaper isn't quite right. Here's what the 2026 numbers actually show:
| Factor | Prefab ADU | Stick-Built ADU |
|---|---|---|
| Cost per sq ft (installed) | $220–$350 | $250–$380 |
| Timeline (permit to move-in) | 3–6 months | 8–14 months |
| Customization | Limited to moderate | Unlimited |
| Quality consistency | High (factory QC) | Variable (crew dependent) |
| Financing options | More limited | Standard construction loans |
Prefab saves you 10–20% on average — but the real savings is time. A stick-built ADU that takes 12 months means 12 months of carrying costs, construction disruption, and delayed rental income. A prefab unit that's livable in 4 months starts earning rent 8 months sooner. At $2,000/month in rental income, that's $16,000 in opportunity cost.
For a deeper dive into this comparison, check out our custom ADU vs. prefab comparison which covers pros, cons, and real-world case studies.
The Complete Cost Breakdown: Where Every Dollar Goes
Understanding the anatomy of your ADU budget helps you make smarter trade-offs. Here's where the money actually goes, based on 2026 national averages for a mid-range 600-square-foot detached ADU totaling approximately $200,000.
Hard Costs (65–75% of Total Budget)
Hard costs are the physical construction — materials and labor to build the thing.
| Cost Category | Range | % of Total |
|---|---|---|
| Foundation (concrete slab) | $5,000–$25,000 | 3–12% |
| Framing and structural | $15,000–$50,000 | 8–25% |
| Roofing | $5,000–$15,000 | 3–8% |
| Plumbing (rough + finish) | $8,000–$20,000 | 4–10% |
| Electrical (rough + finish) | $6,000–$15,000 | 3–8% |
| HVAC system | $5,000–$15,000 | 3–8% |
| Insulation | $3,000–$8,000 | 2–4% |
| Interior finishes | $15,000–$50,000 | 8–25% |
| Exterior finishes | $10,000–$30,000 | 5–15% |
| Hard cost subtotal | $72,000–$228,000 | 65–75% |
Interior finishes are where homeowners have the most control over cost. The gap between IKEA cabinets and custom cabinetry, between luxury vinyl plank and hardwood, between a basic pedestal sink and a floating vanity with quartz countertop — that's where $20,000–$40,000 of budget flexibility lives.
Soft Costs (20–30% of Total Budget)
Soft costs are everything that isn't physical construction — design, permits, management.
| Cost Category | Range | % of Total |
|---|---|---|
| Architectural / design plans | $5,000–$20,000 | 3–10% |
| Engineering (structural, civil, soils) | $3,000–$10,000 | 2–5% |
| Permits and plan check fees | $2,000–$15,000 | 1–8% |
| Utility connection fees | $2,000–$10,000 | 1–5% |
| Title 24 energy compliance (CA) | $1,500–$4,000 | 1–2% |
| Survey and site assessment | $1,000–$3,000 | 0.5–2% |
| Soft cost subtotal | $14,500–$62,000 | 20–30% |
The average building permit cost nationally is $1,350 according to 2026 construction data, but this varies wildly. California cities can charge $5,000–$15,000 in permit and impact fees. Some municipalities have reduced or eliminated ADU permit fees to encourage housing development — check our state-by-state ADU cost guide for specifics in your area.
General Contractor Markup (10–20% of Hard Costs)
Your general contractor typically charges 10–20% of total hard construction costs as their fee, which translates to roughly $50–$150 per hour or $300–$500 per day for a licensed GC. On a $200,000 project, expect the GC fee to be $20,000–$40,000.
Some homeowners try to act as their own general contractor to save this fee. It's possible but risky. Managing subcontractors, scheduling inspections, ordering materials, and coordinating trade sequencing is a full-time job. One scheduling mistake — pouring concrete before the plumbing rough-in is inspected, for example — can cost you thousands in rework. Unless you have construction experience, the GC fee is money well spent.
ADU Costs by State: Regional Pricing Reality Check
Geography is arguably the single biggest cost driver for ADU construction. The same 600-square-foot detached ADU that costs $150,000 in Texas might cost $300,000 in coastal California. Here's why.
High-Cost States (Above National Average)
| State / Region | Cost Per Sq Ft | Avg. 600 Sq Ft ADU | Key Cost Driver |
|---|---|---|---|
| California (coastal) | $250–$400 | $200,000–$380,000 | Labor ($48–$70/hr), materials 28% above national avg |
| New York (metro) | $275–$380 | $220,000–$350,000 | Labor rates, union requirements |
| Massachusetts | $240–$360 | $190,000–$320,000 | Older lots, complex permitting |
| Washington (Seattle area) | $230–$340 | $180,000–$300,000 | Seismic requirements, high demand |
| Colorado (Front Range) | $220–$310 | $170,000–$280,000 | Rapid growth, labor shortage |
Mid-Cost States (Near National Average)
| State / Region | Cost Per Sq Ft | Avg. 600 Sq Ft ADU | Key Cost Driver |
|---|---|---|---|
| Oregon | $200–$280 | $150,000–$240,000 | Progressive ADU laws keep demand high |
| Virginia | $180–$260 | $140,000–$220,000 | Moderate labor, variable permitting |
| North Carolina | $170–$250 | $130,000–$210,000 | Growing demand, reasonable labor |
| Illinois (Chicago) | $190–$280 | $145,000–$235,000 | Winter construction delays |
| Minnesota | $185–$270 | $140,000–$225,000 | Cold climate insulation requirements |
Lower-Cost States (Below National Average)
| State / Region | Cost Per Sq Ft | Avg. 600 Sq Ft ADU | Key Cost Driver |
|---|---|---|---|
| Texas | $150–$230 | $110,000–$190,000 | Lower labor, fewer regulations |
| South Carolina | $150–$220 | $105,000–$180,000 | Labor $38–$58/hr, lower material costs |
| Ohio | $140–$210 | $100,000–$175,000 | Affordable labor, less regulation |
| Georgia | $155–$235 | $115,000–$195,000 | Growing market, moderate costs |
| Louisiana | $145–$215 | $100,000–$170,000 | Low labor costs, hurricane specs add some |
These ranges reflect 2026 data from CostToConstruct and regional construction indices. Keep in mind that costs within any state vary significantly between metro and rural areas. Building in downtown Austin costs 30–40% more than building in a small Texas town two hours away.
For a complete breakdown of every state, check our ADU construction costs by state guide.
How to Actually Save Money on Your ADU (Without Cutting Corners)
Most "save money on your ADU" advice is useless — no one needs to be told to "get multiple bids." Here are the strategies that actually move the needle in 2026.
Choose the Right ADU Type for Your Property
This is the biggest decision you'll make, and it's worth repeating: a garage conversion at $80,000–$150,000 costs roughly half what a detached new build costs. If you have a usable garage and don't desperately need the parking, start there. The ROI math is significantly better when your upfront cost is lower.
Use Pre-Approved Plans
Many cities now offer catalogs of pre-approved ADU floor plans. Using one can slash your design costs from $15,000–$20,000 down to $2,000–$5,000 and shave weeks off the permitting process. San Jose, Los Angeles, Portland, and Seattle all have pre-approved plan programs as of 2026.
The trade-off is reduced customization. But for most homeowners building a straightforward one-bedroom ADU, the pre-approved plans are perfectly functional. You can still choose your own finishes, fixtures, and exterior materials.
Time Your Build Strategically
Construction follows seasonal patterns. In most markets, contractors are busiest from April through October. Starting your project in late fall or winter can get you:
- 5–15% lower labor bids (contractors want to keep crews working)
- Faster permitting (fewer applications in the queue)
- Better material availability
The exception is cold-climate states where winter construction is genuinely problematic. In Minnesota or Michigan, waiting until spring makes more sense.
Consider Phased Construction
If your budget is tight, some homeowners build the shell and rough-in during Phase 1, then complete interior finishes in Phase 2 a few months later. This spreads the cost across two payment cycles. Not all contractors will agree to this, and it adds complexity, but it's a legitimate strategy for homeowners who can't access construction financing.
Don't Over-Improve for Your Market
A common mistake: spending $350,000 on a luxury detached ADU in a market where comparable rentals top out at $1,800/month. Run the numbers before you choose your finish level. If mid-grade finishes get you 90% of the rental income that high-end finishes would, the extra $50,000–$80,000 in upgrades doesn't pay for itself.
Your complete ADU guide has more on optimizing your ADU investment for maximum return.
Explore Fee Waivers and Incentives
Several states and municipalities have reduced or eliminated ADU-related fees to boost housing supply:
- California: Many cities have waived impact fees for ADUs under 750 sq ft (saving $5,000–$20,000)
- Oregon: State law limits system development charges for ADUs
- Washington: Seattle waived sewer connection fees for ADUs through 2026
- Portland: Offers fee waivers and expedited permitting for ADUs
These incentives change frequently. Check with your local planning department before budgeting — a $10,000 fee waiver can meaningfully shift your project economics.
Financing Your ADU: What Actually Works in 2026
You've got the budget estimate. Now, how do you pay for it? ADU financing has matured significantly since the early days when your only options were cash, a HELOC, or a construction loan. Here's the current landscape.
Home Equity Line of Credit (HELOC)
Still the most common ADU financing method. You borrow against your existing home equity at variable rates currently running 7.5–9.5% (as of early 2026). HELOCs work well for smaller projects like garage conversions where you need $80,000–$150,000.
Pros: Fast approval (2–4 weeks), flexible draw schedule, interest-only payments during construction. Cons: Variable rate risk, requires substantial home equity (most lenders cap at 80–85% combined LTV).
Cash-Out Refinance
If your current mortgage rate is already high, a cash-out refinance lets you roll ADU costs into a single mortgage payment. With current rates around 6.5–7.5%, this makes sense only if your existing rate is above 6%.
Pros: Fixed rate, single payment, potentially tax-deductible interest. Cons: Closing costs (2–5% of loan), resets your mortgage term, requires strong credit.
Construction Loan
Purpose-built for ADU projects, construction loans fund the build in draws as work progresses. They typically convert to a permanent mortgage after construction is complete.
Pros: Structured for construction, funds released with inspections, competitive rates. Cons: Complex application process, requires detailed plans and contractor bids, 6–12 month approval process.
ADU-Specific Lending Programs
Several lenders now offer ADU-specific products that simplify the process:
- RenoFi: Bases lending on the after-renovation value of your property, allowing you to borrow more
- Genesis Capital: Specializes in ADU construction loans with streamlined underwriting
- CalHFA ADU Grant: California's $40,000 forgivable loan program for qualifying homeowners (income-restricted)
Making sure you have the right ADU insurance coverage in place before construction starts is just as important as securing financing. Most standard homeowner policies don't automatically cover a new structure during or after construction.
Timeline and How It Affects Your Total Cost
Time is money — literally, when it comes to ADU construction. Every month of delay means another month of carrying costs on your construction loan, another month of lost rental income, and another month of living on a construction site.
Realistic ADU Timelines by Type (2026)
| ADU Type | Design + Permits | Construction | Total |
|---|---|---|---|
| Garage conversion | 1–3 months | 2–4 months | 3–7 months |
| Interior conversion | 1–2 months | 2–3 months | 3–5 months |
| Attached addition | 2–4 months | 4–7 months | 6–11 months |
| Detached new build | 2–5 months | 5–10 months | 7–15 months |
| Prefab / modular | 1–3 months | 1–3 months (on-site) | 3–6 months |
California ADU construction typically requires 4–10 months from permit to completion according to 2026 data, though complex projects in jurisdictions with slow permitting can stretch to 12–15 months.
The Cost of Delays
Every month your project runs over schedule costs you in multiple ways:
- Construction loan interest: $500–$1,500/month on a $200,000 project
- Lost rental income: $1,500–$3,000/month depending on market
- Contractor general conditions: $1,000–$2,500/month for site management, equipment rental, port-a-potty, etc.
- Opportunity cost: Money tied up in construction can't earn returns elsewhere
A project that runs 3 months over schedule can easily cost an additional $6,000–$20,000 in combined carrying costs and lost income. This is why the prefab timeline advantage — saving 4–8 months versus stick-built — has real dollar value beyond just convenience.
How to Keep Your Project on Schedule
- Get permits before hiring a contractor: The permitting phase is the most unpredictable. Don't start paying a contractor until permits are in hand.
- Lock in materials early: Supply chain disruptions still affect certain materials (windows, specialty fixtures, specific lumber grades). Order long-lead items during the design phase.
- Build in weather contingency: Add 2–4 weeks to your construction timeline for weather delays. This is planning, not pessimism.
- Weekly site meetings: Meet with your contractor weekly. Projects that drift do so gradually — weekly check-ins catch problems before they become expensive.
Frequently Asked Questions
What is the cheapest type of ADU to build in 2026?
A garage conversion remains the most affordable ADU type in 2026, typically costing between $80,000 and $150,000 for a two-car garage. The structure already exists — walls, roof, foundation — so you're primarily investing in the interior buildout, utility connections, and code compliance upgrades. Interior conversions of existing basements or bonus rooms can be even cheaper ($40,000–$95,000) if the space already has some utility infrastructure. The key factor is leveraging existing structure to avoid the highest construction costs: foundation, framing, and roofing.
How much does a 500-square-foot detached ADU cost?
A 500-square-foot detached ADU costs between $125,000 and $175,000 nationally in 2026, or roughly $250–$350 per square foot when you include site preparation, foundation, utility connections, and permits. In high-cost markets like California, that same unit can run $175,000–$250,000. This includes the full installed cost — not just the structure. Site work alone (grading, utility trenching, foundation) typically adds $20,000–$50,000 on top of the basic construction cost, which is why detached ADU budgets need to account for more than just the building itself.
Is a prefab ADU cheaper than a stick-built ADU?
Prefab ADUs are generally 10–20% less expensive than comparable stick-built units when you compare total installed costs. A mid-range 600-square-foot prefab ADU typically costs $160,000–$250,000 fully installed, versus $180,000–$280,000 for stick-built. But the bigger savings come from time — prefab projects finish 4–8 months faster, which means less construction loan interest and earlier rental income. The trade-off is limited customization. If you want a specific layout, unique architectural features, or need to build on a challenging lot (steep slope, tight access), stick-built gives you flexibility that prefab can't match.
Do ADU costs include permits and design fees?
Quoted ADU costs from builders may or may not include permits and design fees — always ask explicitly. Permits alone range from $1,350 (national average) to $15,000+ in high-fee jurisdictions like some California cities. Architectural design adds another $5,000–$20,000, though pre-approved plans from your city can reduce this to $2,000–$5,000. Engineering, surveys, and utility connection fees add another $5,000–$15,000. All told, soft costs typically represent 20–30% of your total ADU budget. A builder who quotes you $180,000 without specifying whether soft costs are included could actually be a $230,000 project.
How much can I save by owner-managing my ADU project?
Acting as your own general contractor can save the 10–20% GC markup — typically $20,000–$40,000 on a $200,000 project. However, this requires significant construction knowledge and time investment. You'll be responsible for hiring and scheduling subcontractors, ordering materials, coordinating inspections, and managing the construction sequence. One scheduling mistake (like drywalling before an inspection) can cost thousands in rework. Most ADU experts recommend owner-management only for homeowners with construction or project management experience. For everyone else, the GC fee is essentially insurance against costly mistakes and delays.
Related Reading
- How Much Does an ADU Cost in 2026? — Our comprehensive ADU cost overview covering all pricing factors
- ADU Construction Costs by State — Detailed state-by-state pricing with regional cost drivers
- Complete ADU Guide 2026 — Everything you need to know about planning, building, and renting an ADU
- ADU Insurance: Do You Need Separate Coverage? — Protecting your investment during and after construction
-- The Blueprint Team
META_DESCRIPTION: ADU construction costs $40,000–$380,000 in 2026. Compare pricing for garage conversions, attached, detached, and prefab ADUs with detailed cost breakdowns by type.