ADU Cost In 2023: Detailed ADU Development Cost Breakdown

Jul 31, 2023 | ADU

As ADU professionals, the most frequent inquiry we receive is regarding the cost of building an ADU.

Many prospective ADU developers are astonished by the actual expenses involved. These costs often do not align with what they have come across online or the information provided by contractors.

It is crucial to grasp that developing an ADU closely resembles to developing a new house. As such, the process and associated costs are comparable to those encountered when building a new home, albeit with a few adjustments.

Before embarking on your ADU planning journey, it’s essential to be mindful of the four primary costs associated with ADU development:

  1. Design and planning
  2. City fees
  3. Construction labor and material
  4. Finish materials

Keep in mind that these categories are only general classifications. Each category can be further broken down into individual items, and the cumulative sum of these items determines the total cost within that category.

ADU Design and Planning Costs

The intricacies of ADU design and planning often surpass the initial expectations of many individuals. At the outset, you’ll find yourself working alongside a team of skilled professionals to obtain an array of crucial drawings and calculations required for the project. This category entails several costs, can in include some or all of the following, depends on ADU type, but not limited to:

  1. Architectural Design: The fees associated with hiring a designer to create detailed ADU plans and blueprints tailored to your ADU’s specific requirements.
  2. Engineering: Costs related to consulting with structural engineers who ensure the structural integrity and safety of the ADU design.
  3. Interior Design and Consultation: If desired, fees for interior designers to assist with optimizing space and creating a functional and aesthetically pleasing interior.
  4. Surveys and Assessments: Fees for land surveys and site assessments to evaluate the feasibility and suitability of your property for ADU development.
  5. Soil and Geotechnical Testing: The costs of conducting soil tests to determine the soil’s stability and bearing capacity, critical for foundation design.
  6. Energy Modeling: Utilizing specialized software to simulate the ADU’s energy usage, performance and evaluate different design options for energy savings.
  7. Solar or Renewable Energy Integration: Evaluating the feasibility and cost of incorporating solar panels or other renewable energy systems to offset energy consumption.

These are just some of the various components encompassed within the design and planning category, each contributing to the overall cost of your ADU development.

The costs associated with design and planning will differ for each individual based on their specific requirements and preferences.

On average, basic expenses for ADU design and planning stage typically range from $6,000.00 to $14,000.00.

Your position within this range is entirely dependent on factors such as your design preferences, the size of the ADU, and the professionals you engage with – finding collaborators who genuinely work with you rather than solely focusing on financial gains. For some ADU’s it might be  above this range, as the basics will not be sufficient.

Check out our Guide to ADU Development for a design and planning budgeting sheet to help you get an accurate idea of how much your ADU will cost.

ADU Design and Planning Costs

City & County Fees Associated with ADUs

When developing an ADU in any city, there will be various city fees that you must pay to comply with local regulations and obtain the necessary permits. These fees are essential for funding city services and ensuring that your ADU adheres to zoning and building codes. Some of the common city fees associated with ADUs include:

  1. Plan Check and Review Fee: Additional costs for the city to review your ADU plans and ensure compliance with building codes.
  2. Planning and Zoning Fee: A fee related to the evaluation of your ADU project against the city’s zoning regulations and land-use requirements.
  3. Impact Fees: These fees are assessed to offset the impact of additional development on city infrastructure and services, such as schools, parks, and transportation.
  4. Sewer and Water Connection Fees: Charges for connecting your ADU to the municipal sewer and water systems.
  5. School Fees: In some areas, there might be fees associated with school impact, which contribute to the local education system.
  6. Fire Department Fees: If your ADU requires a fire safety inspection, there may be fees associated with this service.
  7. Utility Fee Deposits: Some cities may require a deposit to ensure the payment of utility bills associated with the ADU.
  8. Impact Fees: These fees are assessed to offset the impact of additional development on city infrastructure and services, such as schools, parks, and transportation.
  9. Certificate of Occupancy Fee: A fee to obtain a certificate of occupancy, confirming that your ADU meets all necessary requirements and is fit for habitation.

It’s important to note that the specific fees and their amounts can vary significantly from one city to another. They can also depend on factors such as the size of the ADU, its location, and the complexity of the project. Be sure to research and understand the city fees applicable to your ADU development to budget accordingly and avoid any surprises during the construction process. Consulting with your local planning department or a professional ADU builder can help you navigate through these fees more effectively.

The fees will differ from one city to another. However, it’s important to note that most city fees are fixed and depend on the size and valuation of your ADU.

On average, the total cost of ADU city fees falls within the range of $3,000.00 to $11,000.00.

ADU Construction Labor and Material Costs

When it comes to construction labor, the fees charged by contractors can vary significantly based on their expertise and reputation. It is crucial to remember that opting for the cheapest contractor may lead to undesirable outcomes. Such contractors might lack the necessary experience and skills, and they may surprise you with hidden fees later on, potentially compromising the quality of your ADU project.

Regarding material costs, experienced contractors often have established relationships with local suppliers, enabling them to offer cost-saving deals to clients. However, it’s essential to recognize that your chosen designs and material selections will greatly influence the overall expenses in this category.

Numerous factors influence the overall cost of construction and materials for your ADU project. These parameters include:

  1. Design and Plans: The complexity and uniqueness of your ADU’s design and architectural plans.
  2. Structure Type: Whether your ADU is a detached unit or a garage conversion, which can impact labor and material requirements.
  3. Size: The size of the ADU will significantly affect the total construction and material costs.
  4. Conditions of Property: The state of your property’s terrain and the need for any site preparation or adjustments.
  5. Conditions of the Existing Structure (for garage conversions): If converting an existing structure, the condition and modifications needed will influence costs.
  6. Distance and Location of Utility Connections: The distance to utility connections and the ease of access can impact installation expenses.
  7. Cost of Materials (Rough and Finish): The choice of materials, both for the initial construction (rough) and the final touches (finish), will influence the overall budget.
  8. Energy Efficiency: If you prioritize energy-efficient features in your ADU, the upfront costs may be higher, but it can lead to long-term savings on energy bills.

Larger ADUs generally have higher total costs due to the increased materials and labor required. However, the cost per square foot typically decreases with larger ADUs. For instance, a detached 1,200 square foot unit may have a lower cost per square foot compared to a 400 square foot unit.

Keep in mind that building a second story will significantly increase costs, potentially raising the cost per square foot by up to 50%. It is essential to consider this aspect thoroughly before deciding whether a second story is necessary for your ADU project.

Calculating Your ADU Construction Labor and Material Costs

On average, the cost of constructing a conversion ADU typically falls within the range of $175.00 to $225.00 per square foot.

This type of ADU involves transforming an existing structure, such as a garage, into a livable space, which can offer cost-saving benefits compared to new construction.

On the other hand, if you are planning to build a new construction ADU from scratch, the expenses will generally be higher.

You can anticipate paying anywhere between $250.00 to $350.00 per square foot for construction labor and materials if you are building ADU from scratch.

ADU Finish Materials Costs

Effective budgeting for finishing materials is crucial, as they play a pivotal role in giving your almost completed ADU a decorative and appealing appearance. These finish materials add the final touches that enhance the overall look and feel of your living space. Some essential finish materials you’ll need for your ADU include and limited to:

  • Flooring: Choose from various options such as hardwood, laminate, tile, vinyl, or carpet, depending on your preferences and budget.
  • Doors: Consider the style and material of doors that best complement the design and theme of your ADU.
  • Windows: Select energy-efficient windows that provide ample natural light and ventilation while aligning with your ADU’s aesthetics.
  • Cabinetry: Opt for high-quality cabinetry for the kitchen, bathroom, and other storage spaces, maximizing functionality and aesthetics.
  • Tile: Use tiles for backsplashes, showers, or flooring to add visual appeal and practicality to specific areas.
  • Stone: Incorporate natural or engineered stone for countertops, fireplaces, or accent walls, adding a touch of elegance to the interior.

On average, budgeting for ADU finish materials typically amounts to around $50.00 to $100.00 per square foot.

However, the actual costs may vary depending on the quality, brand, and specific materials you choose. Here are some factors that can influence the overall cost of finish materials:

  1. Material Quality: Higher-quality materials may come with a higher price tag but often offer enhanced durability and aesthetics.
  2. Design Complexity: Intricate designs or custom-made elements may incur additional costs.
  3. Room Sizes: Larger rooms with more surface area will require a higher quantity of finish materials, affecting the overall expenses.
  4. Material Selection: Different materials have varying price ranges, so your choices will influence the final cost.

To ensure you stay within your budget, it’s essential to research and compare prices, explore various material options, and plan ahead for your ADU’s finishing phase. Working with experienced contractors or interior designers can also help you make informed decisions and achieve the desired look while managing costs effectively.

Discover comprehensive insights into budgeting for finish materials and other crucial aspects of each category through the ADU eCourse. This exceptional resource offers a plethora of valuable and in-depth videos, along with complimentary bonus materials to guide you through every step of the ADU building process. Whether you’re a beginner or experienced in ADU development, this eCourse is designed to equip you with the knowledge and tools needed to make informed decisions and successfully navigate the complexities of building an ADU.

ADU Finish Materials Costs

Type Of ADU Development That Effects Costs

ADUs development come in two primary types: new construction and garage/structure conversions. Among these options, a garage conversion typically presents a cost advantage, being around 20%-25% cheaper compared to constructing a similar-sized new ADU. The cost savings are mainly attributed to utilizing the existing foundation, framed walls, and roof of the garage.

However, it’s important to note that the actual cost difference also hinges on the condition of these existing elements. If the garage’s foundation, walls, or roof are in poor shape, they may require significant repairs or replacement, which can offset the cost advantage of a garage conversion.

If your garage is in an extremely deteriorated state, it’s crucial not to expect significantly lower costs compared to building a new ADU from scratch. The expenses for extensive repairs or rebuilding can narrow the cost gap between garage conversions and new construction.

Remember that both types of ADUs have their advantages and considerations. While a garage conversion can offer cost savings and reutilize existing space, new construction provides more design flexibility and the opportunity to tailor the ADU to your specific needs and preferences. Weighing these factors will help you make the best decision for your ADU project.

Total ADU Costs

In summary, determining the total average cost of your ADU involves considering several factors discussed earlier. These factors encompass various categories, including design and planning, city fees, construction labor and material costs, and finishing materials.

Main ADU Cost CategoryAverage ADU Price Range
Design And Planning$6,000 – $14,000
City Fees$3,000 – $11,000
Construction Labor and Materials$175 – $350 / Sqf
Finish Materials$50 – $100/Sqf

It is essential to bear in mind that the costs of your ADU project depend on various factors, and careful consideration of each element will influence the final expenses. Some crucial factors that influence project costs include:

  1. Project Size: The overall size and square footage of your ADU will directly impact the material quantities, labor hours, and related costs.
  2. Various City Fees Applied: Each city has its own set of fees for permits, inspections, and impact fees, which contribute to the overall project expenses.
  3. Project Location: The geographical location of your ADU construction can affect labor rates, material prices, and local regulations, influencing the budget.
  4. Design Type: The complexity and customization of your ADU design may result in higher costs due to specialized materials or architectural elements.
  5. Existing Garage Condition of Framing and Foundation: For garage conversions, the state of the existing structure’s framing and foundation may require repairs or modifications, impacting costs.
  6. Proximity of Utility Connections: The distance and accessibility of utility connections (water, electricity, sewer) can affect the installation expenses.
  7. Owner Selection of Finish Materials: The choice of finish materials, such as flooring, doors, windows, and cabinetry, will influence the overall aesthetic and budget.

Therefore, your decisions regarding the size, location, design, and materials will have a significant impact on the project’s total cost.

It’s crucial to conduct thorough research and obtain estimates for all the necessary components of your ADU development. Getting detailed quotes from professionals will give you a clearer understanding of the potential expenses involved.

Furthermore, it’s wise to build in a contingency buffer in your budget. Having extra funds set aside provides financial flexibility in case unforeseen challenges or changes arise during construction. This safety net ensures that your ADU development won’t be delayed or halted due to under-budgeting, preventing unnecessary stress and setbacks.

By diligently assessing all these factors and planning ahead with a realistic budget, you can embark on your ADU project with confidence, knowing you have considered all the necessary aspects to bring your vision to life successfully.

ADU Costs Examples

When evaluating the total cost of an ADU, it can be challenging to ascertain the precise expenses, especially when considering construction labor, materials, and finish materials, which are often calculated on a per square foot basis.

To provide you with a clearer understanding of potential total costs, we offer two examples below:

  1. One for a new construction ADU with a size of 450 square feet,
  2. And another for a garage conversion ADU utilizing a two-car garage space assuming it’s a 450 Sqf.

These examples will give you a realistic idea of what each type of ADU may cost you:

Main ADU Cost CategoryNew ADU Construction 499 Sq.ft.2 Car ADU Garage Conversion
Design And Planning$7,500-$9,000$6,500 – $7,500
City Fees$4,000-$5,000$4,000-$5,000
Construction Labor and Materials$112,500 – $157,500$78,750 – $101,250
Finish Materials$22,500 – $45,000$22,500 – $45,000
Average Total Costs$146,500 – $216,500$111,750 – $158,750

The estimated new construction costs are calculated for a one-bedroom, one-bathroom, 450 square foot ADU. Based on the industry average, construction labor and materials will range from $250 to $350 per square foot.

On the other hand, for a 2-car garage conversion, the construction labor and materials are expected to average around $175 to $225 per square foot. The average size of a 2-car garage falls within the range of 300 to 475 square feet. For the purpose of these cost estimates, we assume a 450 square foot 2-car garage.

As for finish materials, they are anticipated to cost approximately $50 to $100 per square foot for both the new construction and the garage conversion ADUs.

By reviewing these examples, you can gain a better grasp of the potential costs associated with each type of ADU. However, it’s important to remember that these figures are estimates, and the actual total cost may vary based on numerous factors, including design complexity, location, material choices, and any specific requirements or upgrades you may desire.

To determine your specific ADU’s total cost, it’s recommended to work closely with experienced ADU professional. They can provide you with more accurate cost estimates based on your unique preferences, project scope, and the current market conditions in your area.

Remember, budgeting for your ADU project requires careful consideration and adequate research to ensure that you have a realistic estimate of the total expenses involved.

ADU Size Matters

Additionally, it is essential to consider that the above-mentioned new construction ADU is based on a 450 square foot example. The minimum living area required for an ADU is 150 square feet, which means new construction ADUs can be significantly more affordable than the above example when designed at the minimum size. On the other hand, if an ADU reaches its maximum allowable size of 1200 square feet, the costs can increase significantly, potentially becoming much more expensive than the 450 square foot example.

ADU Costs Examples

Creating Your ADU Budget

Your total costs are likely to align with the average estimates provided earlier. However, for a more accurate understanding of your specific ADU expenses, we offer a free ADU Cost Calculator. Simply input details about your desired ADU, and the calculator will swiftly generate an estimate for labor and materials, helping you gain better clarity.

Moreover, we invite you to schedule a complimentary consultation with us. This will provide you with a more comprehensive insight into the various aspects involved in ADU development and ensure that your contractor estimates encompass the entire scope of the project. Our consultation will help you make well-informed decisions, understand the intricacies of ADU development, and enable you to move forward with confidence.

Always Start with A Budget

One of the most significant mistakes in ADU development is neglecting to create a budget early in the process. Establishing a budget is crucial as it serves as a guiding framework to determine which type of ADU will best suit your needs and financial capabilities. As seen in our earlier comparison of average costs between a garage conversion and new construction, understanding the differences can significantly influence your decision.

Furthermore, having a budget in place helps you avoid unnecessary expenses throughout the project. By allocating specific amounts to each category, you can stay on track and prevent overspending on non-essential items or add-ons that might catch your eye later on.

It’s essential to maintain control over your budget and not let your contractor solely set it for you.

Relying on a contractor’s blind estimates without having detailed designs, plans, or engineering in place can lead to potential oversights and unchecked costs. Being in control of your budget allows you to make informed decisions and ensures that your ADU development aligns with your financial constraints and preferences.

Don’t Let Your Contractor Set Your Budget

If a contractor takes full control over the budget, you may face challenges in monitoring and balancing the project’s financial aspects. This lack of oversight could lead to unexpected expenses and an overall increase in spending beyond what you initially intended.

To avoid these pitfalls, it’s crucial to begin by developing a detailed budget, considering various factors such as construction costs, city fees, and finish materials. Seek professional guidance and consult with experienced ADU professional to obtain more accurate cost estimates. Armed with a well-defined budget and reliable information, you can confidently manage your ADU development and achieve your desired outcomes while staying within your financial boundaries.

Don’t Compromise on Essentials

Effectively budgeting your ADU involves making informed decisions on where you can economize and where you should not compromise on essential elements. Avoid the mistake of cutting expenses by eliminating crucial features that significantly impact the livability and functionality of your ADU:

  1. Not Including a Laundry Area: Overlooking a dedicated laundry space can lead to inconvenience and added expenses in the long run. A laundry area is a practical and valuable addition that enhances the ADU’s functionality and saves time and effort.
  2. Removing Windows: Windows provide natural light, ventilation, and a sense of openness. Eliminating them may result in a dark, claustrophobic living space, which is not desirable for comfortable living.
  3. Not Planning for Enough Storage: Adequate storage is vital for keeping the ADU organized and clutter-free. Cutting back on storage solutions can lead to a cramped and disorganized living environment.
  4. Hiring the Cheapest Contractor: Opting for the cheapest contractor without considering their qualifications and experience can lead to subpar workmanship, potential delays, and hidden fees that can ultimately cost you more in the long term.

However, if you are looking to reduce ADU expenses without compromising livability, consider these cost-saving measures:

  1. Opting for More Affordable Finish Materials: While quality is essential, you can explore cost-effective finish materials that offer a balance between aesthetics and budget.
  2. Cutting Down on Square Footage: Evaluate your needs and determine if you can achieve your ADU goals with a slightly smaller footprint, as reducing square footage can positively impact costs.
  3. Make It All-Electric (No Gas): Designing an all-electric ADU can lead to energy-efficient solutions and lower utility costs, making it a more budget-friendly choice in the long run.
  4. Have Only One Plumbing Wall: Minimizing plumbing requirements can help reduce construction expenses, but ensure it does not hinder the ADU’s functionality or convenience.

Remember, cutting down on expenses should be approached with caution, and it should never compromise the quality of life for the occupants. Prioritize essential features and consult with ADU experts to find the right balance between cost savings and creating a comfortable, functional, and enjoyable living space. A well-thought-out budget ensures a successful ADU project that meets both your financial objectives and lifestyle needs.

Budget For ADU Appliances and Furniture

Similar to building a new home, furnishing your ADU requires thoughtful consideration of costs and space optimization. Unlike a larger home where you can transfer furniture and appliances from your current residence, an ADU’s limited space necessitates investing in new, compact appliances and furniture that perfectly fit the available area.

To maximize the functionality of your ADU, compact appliances play a pivotal role, ensuring efficient utilization of space. However, it’s essential to be mindful of the associated costs. Equipping your ADU with the necessary appliances and furniture is crucial to create a comfortable living space. An unfurnished ADU with no kitchen or water heating would not be ideal for anyone.

Our ultimate guide to ADU appliances and furniture provides valuable insights and ideas to help you understand what your ADU may require and the corresponding costs. Exploring this guide will give you a clear understanding of the necessary investments and enable you to budget effectively for furnishing your ADU.

When choosing appliances and furniture, focus on multifunctional and space-saving pieces to optimize the limited area. Customizing your choices to suit your ADU’s specific layout and functionality will ensure you make the most of the available space while creating a cozy and practical living environment.

Remember, the key is to strike a balance between furnishing costs and the level of comfort and functionality you want to achieve. By planning carefully and referring to expert resources like our ultimate guide, you can furnish your ADU thoughtfully and make it a welcoming and efficient living space without overspending.

Start Your ADU Development Today

At Levi Design Build, we specialize in assisting you with budgeting for your ADU to ensure cost-efficiency. If you find budgeting your ADU project challenging, you can rely on us to offer expert guidance while still giving you the freedom to maintain oversight and control over your development.

Unlike some other firms, we keep the design phase team separate from the build phase team, allowing you maximum control over your finances. This approach ensures that you have the flexibility to review and manage the budgeting process with confidence.

Our commitment is to provide you with exceptional service throughout your ADU project, starting from the budgeting phase. We offer a personalized approach to design, planning, project management, and consultation, tailoring our services to meet your specific needs and preferences.

With our assistance, you can properly budget for every aspect of your ADU development, ensuring that you have a clear understanding of the costs involved and how to allocate your resources effectively. From conception to completion, we are dedicated to supporting you at every step, ensuring a smooth and successful ADU project that aligns with your vision and financial goals. You can trust us to be your reliable partner in creating your dream ADU while maintaining financial prudence and delivering the highest level of service.