Before you jump into any major building project, you will want to get a good idea of how much it is going to cost you. The same goes for when you are developing an ADU. That is why we have put together a quick guide on how to do an ADU cost estimate.

Break Up Your Costs Into 4 Major Sections

There are ADU e-courses that provide you with budgeting sheets to help you accurately estimate your ADU costs. We highly recommend using them because they make the estimation process much simpler.

They make ADU estimates easier by breaking them into 4 major sections. Those sections are then broken up into much smaller sections, but having the 4 makes it easier to figure everything out and keep it organized.

Design and Planning

Design and planning is the first major section of ADU costs. It involves things like:

  • Land surveys
  • Engineer calculations
  • Energy calculations
  • Architectural drawings

It also involves figuring out the size of your ADU and how you want it laid out. To give you an idea of how much this should cost between $6,000.00 to $14,000.00.

City Fees

City fees have their own section because they are a relatively fixed cost. Every city has fees associated with:

  • Plan check
  • Impact fees – for certain sizes
  • Utility fees
  • Building permit

They can cost anywhere from $3,000.00 to $11,000.00.

Construction Labor And Material Costs

Construction labor and material costs will vary from contractor to contractor. They are also influenced by:

  1. Design and plans
  2. Structure type
  3. Size
  4. Conditions of property
  5. Conditions of the existing structure (if it is a garage conversion)
  6. Distance and location of utility connections
  7. Cost of materials (rough and finish)

On average, they will cost anywhere between $250.00 to $300.00 per square foot.

Finish Materials

Finish materials bring a decorative look to your ADU. they include things like:

  • Windows
  • Tile
  • Stone
  • Flooring
  • Doors
  • Cabinetry

How much this section will cost you is dependent upon your design tastes. Usually, though, they can cost anywhere from $50.00 to $75.00 per square foot.


Please enter your comment!
Please enter your name here