Whether it's a simple home upgrade or ground-up construction, proper budgeting and cost allocation are the very first step in every project. When it comes to building an ADU, you're going to have different professionals involved and they're all going to cost you differently. Also, you should also consider all the city fees you may incur as you kick off your ADU project. Remember that the costs of these fees are very much dependent on the size of your ADU and its form, is it going to one story? Two stories? Is it an above-a-garage ADU or above your main house? and the list goes on. To help you evaluate all of those things, here are 4 aspects to look into in your ADU budget:
Floor plans and 3D designs even though it's not really a must. we do recommend having that in as part of your process. The city doesn't require those 3D renderings but these are going to help you to do a few things:
If you're going to ask us if it's a good aspect to spend for, then yes we highly recommend you have these as part of your ADU budget.
That's going to be done by another drafter or an architect, those are the actual construction drawings and from that, the construction engineer will need to do his drawings and calculations that you will need to budget for.
This is an essential part of your ADU costs and these calculations are stipulated in Title 24.
In some locations and some cities, you're going to have additional surveys and calculations. On houses located on hillsides for sure, you're going to need a land survey, soil engineer, and most probably retaining walls engineer too. In addition, for any unit that is over 500 square feet you'll also need storm water drainage calculations and those are going to be done by additional professionals and you will need to know first if those are needed so you can budget for those as well.
You are going to have three different fees associated with your project:
Plan check which is basically when you submit the plans, the city is going to charge a fee to review your plans.
Then you're going to have clearances with different utility companies. Each one of them is going to get their own different fee and an address that's going to be assigned to your ADU.
Once your plans are approved, you're going to have the actual permit fee you'll need to pay for before the contractor can start your ADU construction.
The last aspect you need to look out for in your budget is the actual construction of your ADU. We recommend starting budgeting for that,
you can have a range of costs in the beginning before you start the designer planning but once you have plans ready, you should start breaking down the budget in detail. Make sure to have detailed estimates from your contractors and have them well explained to you.
That's going to be provided by the contractor—all labor and all the rough materials and finish materials will be highly dependent on your personal
tastes and needs. It's recommended to choose what you prefer before even starting the project so you can at least have an idea of the actual cost of each item. Also, you can determine the needed quantities of those fixtures and materials so you and the contractor can plan effectively.
Most contractors will not include those in their estimates so you would need to budget for those yourself. To make the budgeting more convenient, list down all the appliances you would want in your ADU and determine the price for each. Also, consider all the needed mechanicals like HVAC ahead of time so the contactors will know what they would be installing.
For smooth and easy budgeting, we recommend you create a spreadsheet where you can list down all the information and categorize it accordingly. In this way, you'll have a more systemized method of allocating costs and expenses. Also, you can closely examine each item you've included, see whether you have overlooked something, overestimated a cost, or needed to spend more on a particular material.