Biggest ADU Building Mistakes (And How to Avoid Them)

Biggest ADU Building Mistakes (And How to Avoid Them)

Some ADU building mistakes are common, but that doesn’t mean you can’t avoid them. Keep reading to learn how!

If you’ve done your fair share of construction projects in the past, you’re probably thinking that building an accessory dwelling unit will be a piece of cake. And, depending on your actual experience, it might be. However, developing an ADU project isn’t the same as building a typical single-family house or a shed. It’s a complicated process that you have to prepare for properly.

new laws and regulations

Even though building an ADU is now easier than ever, thanks to the new laws and regulations that were put in place in an effort to fight the housing crisis, building an ADU still isn’t easy. It’s a massive project that will take time, effort, and money.

In order to not lose any of those three vital things, you must avoid common ADU building mistakes.

Going In With No Research

So, you have space in your yard for an ADU, and your mother-in-law is ready and willing to move in with you. All you have to do now is build an accessory dwelling unit. That will turn your single-family property into a multi-family one. Easy, right? All you have to do is start building.

Well, no.

Before you even start considering starting an ADU building project, you need to do your research. One of the most common mistakes people make is thinking they know enough about construction that they don’t need to do any legwork beforehand. The truth, however, is that you need to find out not only how the actual project will go but also if it’s feasible or not.

Feasibility research is vital because it allows you to see if the project you have in mind is viable before investing money into it. By doing a feasibility study, you’ll see if your property is in an ADU-friendly condition. 

Not Making a Budget (Or Sticking to It)

If the feasibility study gives you the green light for your ADU project, it’s essential that you not go into the project head-first. We often see homeowners start a project without a budget which is, arguably, the biggest mistake you can make. 

ADUs don’t have to cost you an arm and a leg, but they are a significant investment. Not to mention, there are a lot of costs (both obvious and hidden) that you have to calculate into your budget. Otherwise, you might end up with a half-finished project and no more money to complete it.

Opting for turn-key solutions is the easiest route budget-wise. You come up with a budget and your building team executes the project. Easy, right?

Yes. But you still have to think about which costs you’ll have and how much the project will end up costing you. Not to mention, without a budget, you won’t be able to get any financing.

budgeting when building an accessory dwelling unit

When trying to figure out your budget, keep in mind that you’ll have to set money aside for:

  • The overall design, floor plans, and engineering fees
  • Potential city fees, permit fees, and other concession expenses such as inspection fees
  • Rough materials as well as finishing materials
  • Construction costs

Not Being Informed About Local and State Regulations

Although figuring out whether your project could get approval and permits is part of the feasibility study we already suggested you do, it’s also important to get fully informed about all local and state regulations regarding ADUs

As we mentioned several times already, California keeps changing the laws and regulations in order to allow for more affordable housing to be built. That is a dream come true for many prospective ADU owners because it means that the state did everything it could to cut the red tape and make the whole process straightforward.

However, the actual regulations vary from city to city (and county to county). That’s something that you absolutely have to check up on before you start your project. Some cities in California are highly ADU-friendly, while others may have some zoning requirements that could potentially hinder your project. For example, coastal zones have pretty strict requirements when it comes to construction in general.

It’s also essential to check up whether your lot is in a fire hazard zone or a wildland urban interface zone. If it is, that might make executing the project a bit more complicated. Of course, you won’t actually have to worry about any rules and regulations if you hire an excellent team to help you with your project, which brings us to our next point.

Hiring the Wrong Team (Based on Costs Alone)

Hiring the right construction team is vital for your project. First of all, it will ensure that the whole thing goes without a hitch (or at least as smoothly as possible). A builder can make or break your project, which is why you have to pick one carefully. 

Many people opt for low-cost builders to save money. Hiring a team just because they offer the cheapest option might sound like a good idea. But when it comes to things that you should factor in while making your decision, the price should come third. 

However, more often than not, you’ll find that affordability doesn’t always come hand in hand with quality or speed. 

hiring the wrong team to build your adu

So, what does that mean? It means you’ll be left with a badly-done project or wait for months for it to be finished. It’s much more important that you pick a building company with ample experience that can execute your vision flawlessly.

If you’re worried that you can’t afford a high-end building company, consider starting your project in the winter. Builders aren’t as busy during the winter months, which means they might offer more affordable prices.

Not Understanding the Scope of the Project is One of The Biggest ADU Building Mistakes

One of the biggest mistakes you can make is to misunderstand the scope of the project. No matter how much money you throw at it, it will take time. So, it’s vital that you prepare yourself for several weeks (or months) or planning, designing, and construction.

Understanding how long a project will take and how much it will cost is the most important step you can take (and it should be the first one). 

how to optimize space in adu to avoid building mistakes

Not Optimizing the Space

ADUs are completely functional living units. However, by definition, they are much smaller than traditional single-family homes. So, it’s vital that you do the best you can with the little space you have. 

One of the common mistakes people make is not optimizing the space in their ADUs. So, when you’re planning your project and designing your future ADU, it’s essential to pay attention to the space and all the ways you can utilize it.

Not Having Enough Storage

Storage is something people often forget about until they actually need it. When you’re designing your ADU, your goal is to make use of every single inch of space to make the place functional. However, you have to keep in mind that quite a few of those inches should be dedicated to storage.

Having a closet, enough cabinet space in the kitchen and the bathroom, as well as a utility closet or any other form of additional storage, is vital. Otherwise, your ADU won’t be functional at all. 

The best thing you can do here is to raise the ceilings (if possible). You can make good use of all that vertical space. It will make the whole ADU seem bigger and give you more storage space that won’t take away from other rooms. 

Use Natural Light to Avoid ADU Building Mistakes

Not planning for enough windows or poorly placing them throughout your ADU is another common mistake. Having fewer windows will cut the cost of construction, but it will also run up your light bill and potentially put you in a bad mood. Instead, it’s much better to allow for as much natural light into your ADU as possible. 


adu kitchen

When you build an ADU you’ll end up with a compact space. It will be small but it should still be functional. That’s why it’s important that you think about more than just space while you’re designing it. For example, you also have to think about sound.

The bathroom and kitchen will naturally be much closer to the common or sleeping areas in your ADU than they are in a traditional single-family home. 

So, ensure that both are as soundproof as possible. Putting insulated walls between the noisy areas and those areas where you usually need peace and quiet should definitely be on your to-do list.

No ADU Building Mistakes with Cedar Dwellings

Avoiding ADU building mistakes is no easy feat. Even if you do everything right and pick the ideal ADU building team for your project, you might still have some setbacks. But that’s OK!  With the right team by your side, navigating obstacles and stumbling blocks will be a piece of cake.

Cedar turn-key solutions are the optimal way to get an ADU in your backyard as quickly and efficiently as possible. We’ll get the entire project done for you from start to finish and do our very best to execute your vision. And, the best part is, there are no hidden costs. The budget you have is the one we’ll stick to. Not to mention, we also offer help with financing.

So give us a call today and book your free consultation. It’s the first step on the road to getting the ADU of your dreams!