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7 Common Mistakes People Make When Building an ADU

Updated: Nov 1, 2023




If you're thinking of building an Accessory Dwelling Unit, also known as a mother-in-law suite or granny flat, it's important to avoid making costly mistakes.


Many unlicensed builders and cheap contractors take advantage of people who are unfamiliar with the construction process, so it's important to be well-informed before you start building.


In this blog post, we'll discuss some of the most common mistakes people make when building an ADU. We'll also provide tips on how to avoid these mistakes.


1. Not consulting zoning laws

It's important to consult with your local planning department before beginning construction on an ADU. They will have guidelines and regulations for the design and materials used in building an accessory dwelling unit. Unconventional designs or materials may not be up to code and could result in fines or even having to tear down and redo parts of the construction.


Make sure to get all necessary permits before beginning the project and keep open communication with city officials throughout the process. As a bonus, this can also help prevent any potential conflicts with neighbors who may not be happy about the construction. Stay informed about city regulations, zoning laws, and neighborhood associations' rules before starting your ADU project.


At Next Generation Builders we take care of all the building permits with the city on your behalf. We’ll also make sure the construction site and the materials are according to regulation, so you can have peace of mind.


2. Hiring unlicensed builders or contractors.

These individuals may offer a lower price, but they often don't have the proper training or insurance to legally build an ADU. This can lead to major problems with building codes and inspections, not to mention putting your safety at risk. It's always worth it to work with builders that are licensed, bonded, and insured.


Be careful of hiring unknown day labor. You don’t know if installers have criminal records and you may be endangering yourself or end being robbed. They may leave the project unfinished and run with the money. You can avoid this by consulting the civi records and see if there are any lawsuits against the contractors.


Check the references of your contractors (call them) and take into account how long they have been in business. There are just a few that have the trajectory and experience to guarantee an excellent job. In fact, 96% of contractors go out of business within 5 years.


3. Installing inferior products or cheap materials.

This may seem like a good idea to save money in the short-term, but cheap materials often don't last as long and can lead to problems down the road. It's worth investing in high-grade materials that will stand the test of time and maintain the value of your property.


Many of these inferior materials have no warranty so you would be responsible for replacing them once they break down.


When you work with Next Generation Builders, you get the best warranties available:

  • 10 years structural warranty

  • 2 years roof labor warranty

  • 20 years roof manufacturer warranty

  • 2 years of plumbing and electrical labor warranty without material


4. Not optimizing the building space.

When designing and building an ADU, it's important to maximize the limited space available. This means considering factors such as the number of bedrooms, exposure to sunlight, storage space, and even having a laundry room if possible.


It's worth consulting with a professional designer or architect who can help you make the most out of your space. Perhaps you can optimize the space by building a taller ADU. Or you can add a skylight strategically to provide better illumination inside the unit.


All these details will add value to your property and allow you to charge more for rent.


5. Not choosing the right financing option.

There are a few financing options available for building an ADU, including construction loans, taking out a second mortgage, or using a home equity line of credit (HELOC). It's important to weigh the pros and cons of each option and choose the one that is right for your financial situation.


Don't make the mistake of choosing the first financial product you are offered. Compare quotes and interest rates and work with professionals who understand ADU financing. Most agents offered the same financial products to every client, regardless of the type of property. ADUs have their own nuances and are not necessarily the same as the mortgage you would need for your main house. Check out our article on how to finance your ADU.


6. Changing your mind during construction.

According to the Independent Project Analysis Group, an average of over 35% of all construction projects will have a major change.


But making adjustments during the construction process can add both time and money to the project. The general contractor will need to halt construction, order new materials, and make changes. Deciding that you want to add a new window or change the location of the main door after the project has started is a very bad idea.


It's important to have a clear plan before beginning construction and do thorough research on the design and materials you want. Work with professionals who can help you create good plans and designs. Don't approve them until you are 100% satisfied.


7. Choosing unconventional designs.

An ADU is a long-term investment and, as such, you should incorporate universal design principles and elements that will fit all types of people. Whether you are building an ADU for family members or for rent, be sure to include accessibility features for aging adults, such as wheelchair access, wide doorways, lever door handles, grab bars in the bathroom, showers instead of bathtubs and similar features.


Make sure you soundproof you ADU, by adding wall insulation and double-pane windows, for example. Make sure the HVAC unit is the right size for the unit and that there are enough windows for natural light and ventilation.


Avoid these costly mistakes so you won’t have any stress and anxiety during the planning and construction process.


Why work with Next Generation Builders?

Don’t risk your money, safety and peace of mind with cheap labor and unlicensed contractors. An ADU is a large investment that requires the best planning and construction process.


Not only are we affordable and advocate for transparency in pricing, but we are unique in that we offer a Concierge Service to every client:


First, you will have a personal INSIDE Project Representative assigned to your project. You have their name, email and phone number as they are there to answer any and all questions before and after the project is completed. Your representative also handles your financial documents, your scheduling, and any paperwork questions you may have from start to finish.


Second, you will have a personal OUTSIDE Project Manager assigned to your project that is guaranteed not to change from start to finish. Your OPM is the job foreman and will be onsite overseeing every aspect of your installation ensuring your project runs smooth. You will have his email address and phone number and are welcome to contact him at any time.



Are you ready to start the process? Get a Free Estimate Now.


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