Building an Accessory Dwelling Unit (ADU) is a smart investment that can increase your property’s value, generate rental income, and provide additional living space. However, before diving into your ADU project, it's crucial to understand the costs involved.
Factors affecting the cost of ADI construction
Type of ADU
The type of ADU you choose will significantly affect your overall budget:
Detached ADU is a separate apartment separated from the main house. As a rule, such houses are more expensive due to the new foundation, utilities and additional exterior work.
Attached ADU has at least one common wall with the main house, which makes it more economical because it allows you to use existing structures.
Garage ցonversion is often the most affordable option, because it allows you to change the purpose of an existing structure, reducing construction costs.
Basement renovation involves converting an existing basement into a livable space.
Size and layout
A larger ADU with multiple rows or a custom layout will cost more than a more compact and simple design.
Location
The cost of construction is also affected by location. Labor and material prices are often greater in cities, although they may be less expensive in rural locations.
Materials and finishes
Materials and finishes significantly affect prices. High-quality materials and finishes will cost more, although you can find inexpensive options and save money.
Permits and fees
Local permits, impact fees, and regulatory requirements may vary significantly depending on your city or state. Don't forget about this and be sure to review local zoning laws and building codes before proceeding with the project.
Labor costs
Hiring experienced contractors guarantees high quality construction, but labor costs will depend on the complexity of the project and market prices in your area.
Typical Cost Breakdown for an ADU
The total cost of building an ADU depends on various factors, but here’s a general breakdown of the major expenses:
Design & Planning
This includes: Before construction begins, you will have to pay the costs of design, engineering and obtaining permits, which can range from $ 6,000 to $30,000. These include:
Architect & design fees: $3,000 - $15,000
Engineering fees: $1,000 - $5,000
Permits & regulatory fees: $2,000 - $10,000
Construction Costs
After receiving the permit, the main part of the budget will be used for construction. Depending on the size of the ADU, materials, and labor costs, expect that the costs:
Site preparation & foundation: $15,000 - $45,000
Framing & structural work: $20,000 - $50,000
Roofing & exterior finishes: $10,000 - $30,000
Interior finishes (drywall, paint, flooring): $15,000 - $50,000
Plumbing & electrical systems: $10,000 - $30,000
Kitchen & bathroom (cabinets, fixtures, appliances): $15,000 - $40,000
Total Estimated Costs by ADU Type
Detached ADU: $150,000 - $400,000
Attached ADU: $100,000 - $300,000
Garage Conversion: $50,000 - $150,000
Basement Conversion: $75,000 - $200,000
These costs may vary depending on location, choice of materials, labor costs and unforeseen expenses. Proper planning and budgeting will ensure the smoothness of the construction process.
It is important to take into account that landscaping, modernization of engineering networks, furniture and household appliances increase the total cost of the project and should be taken into account in your final budget from the very beginning.
Conclusion: Planning for a Cost-Effective ADU Build
Building an ADU is a significant investment, but with careful budgeting and strategic planning, it can offer long-term financial benefits. Understanding the key cost factors will help you stay within budget and maximize your return on investment.
At EG Modern Construction, we specialize in high-quality, custom ADU builds designed to your specifications and budget. Our team is ready to accompany you at every stage — from design and obtaining permits to construction and final approval.
Do you want to estimate your ADU expenses? Use our ADU cost calculator or contact us today for a consultation!