ADU cost Calculator

Building an ADU, aka Accessory Dwelling Unit, fascinates many homeowners but because of the uncertainty in ADU cost and ROI, they feel they need clarification and cannot make a firm investment decision.

Thus, when homeowners find themselves stuck in this question: what will it cost? This is where the ADU cost calculator jumps in to make things simple for you.

Remember that the actual cost of ADU varies, but with the ADU Cost Calculator, you get an estimated cost that roughly gives you a lump sum amount. 

In this guide, we’ll share what an ADU cost calculator is, how accurate it is, and on what factors it varies. Let’s dive into the details.

What Is an ADU Cost Calculator?

Our ADU Cost Calculator is an online tool that assists you in providing a rough estimate to build an ADU on your property. It entails factors like the type of ADU, size in square foot, bedrooms and bathroom constructions, quality of the finish, chosen site’s challenges, and much more.

P.S. Many ADU cost estimators are available online, but all vary in their details and accuracy as the ADU cost relies on location, size, and design.

How Accurate Is Our Calculator?

As far as the accuracy of the Accessory Dwelling Unit Cost Calculator is concerned, it depends on the complexity of the data provided by the user. Our ADU cost calculator certainly can not calculate a fixed amount required to build an ADU, but yes, it can give you an average cost that caters to a broad spectrum of expenses. 

The best part? Our ADU Cost Calculator accounts for site specifics, like if it is flat or hilly, entails design choices. For fluctuating material costs, it allows you to choose from the quality of finishes i.e., bare, mid-level, or luxury.
For more accuracy, our ADU cost calculator redirect gives you the option to consult with our ADU expert so you can share your requirements and nuances that you missed.

Types Of ADU Costs?

As a homeowner, you need to plan for both hard and soft costs and the contingency cost to address any financial uncertainty during ADU construction. 

Hard Cost

Hard Cost includes the physical and tangible costs that are spent directly on the construction of ADU. This measurable cost entails expenses of labor, materials, framing, wiring, roofing, HVAC system, fixtures, plumbing, etc. 

This substantial cost depends on the material used and the complexity of ADU design. Hard cost is typically the most significant portion of the unit expenses, and their persistence is vital to limit you within the budget. Once you have a clear blueprint about the hard cost of your investment, ROI is in safe hands.

Soft Cost

Soft Cost includes non-physical and indirect expenses that are spent during the construction of ADU. You may wonder what it entails. It contains municipality permit fees, overall engineering and architectural expert fees, ADU consultation fees, and other professional fees that cater to the approval of the place where ADU will be built. For instance, some cities have reduced the permit fees as they want to construct ADU, but others kept the cost high to prevent people from building it.

Contingency Budget/Cost

The contingency budget includes out-of-pocket expenses as this spending is set aside from the hard and soft costs for unexpected and unforeseen events (if they occur). These additional expenses are best for uncertain structural or framing issues, design and layout finishing, or site challenges.
Out-of-pocket expenses did not just cater to these challenges but also included regular price changes in the material or some cushion fund for labor. If you have this cost on your side, we ensure that your project will run smoothly, even if you are stuck in an unforeseen event.
Per our expertise, the contingency budget must range from 5-10% of the total ADU project cost, eventually giving you a fallback budget for an unanticipated financial demand.

How Is ADU Value Calculated?

The final value of ADU relies on many individual factors. Here’s the breakdown of some circumstances on which cost depends:

Type Of Construction

The construction blueprint chosen for ADU is crucial to the overall value. Different types of ADU include Garage conversion, Attached ADU, Detached ADU, Internal ADU, and multi-family ADU. 

Size Of ADU

The size of the ADU is directly under the net value of hard cost and is measurable in square foot. Huge ADUs with more space tend to have higher construction costs, typically running between $100 and $200 per square foot for a basic ADU. 

Property Location

The site location of your ADU project largely influences the central part of the cost. Prices of ADUs will surely increase if it is located in prime locations or high-demand places with some modern amenities. 

Our ADU construction cost calculator will be a valuable tool for calculating a rough estimate to construct an ADU. For more information, consult our ADU experts to clear your doubts.

ADU Cost

Building an Accessory Dwelling Unit (ADU) can be a significant investment with costs usually ranging from $100,000 to $200,000. 


Key cost factors include:

Construction costs These are the largest part of the budget, typically running between $100 and $200 per square foot for a basic ADU. Costs can rise significantly if the ADU is a standalone structure requiring new utility connections.

Permit costs The cost for obtaining necessary permits can vary widely depending on the municipality. Some cities have reduced fees to encourage ADU construction, but others may levy substantial charges.

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