How to Build a Mother-in-Law Suite in the Backyard

backyard dining with in-laws

How to Build a Mother-in-Law Suite in the Backyard

Multigenerational living is en vogue. And in demand.

9min read
by Olesia Chikunova, ADU Specialist.

with in-laws

What Is a Mother-in-Law Suite, and Should I Consider Building One?


Are you caring for an aging parent long distance? There may be a solution that can make it easier for everyone: building a mother-in-law suite in your backyard. Or father-in-law suite. Let us call it a guest suite.

Guess what? Multigenerational living is en vogue.

With the right planning, resources, and careful execution, creating this living space could be just what you need to help maintain your loved one’s lifestyle and add extra space to your primary residence.


This multigenerational housing solution is officially called an accessory dwelling unit (ADU). It has a bathroom, kitchen, bedroom(s), and living area.

A mother-in-law suite that is built and permitted as an ADU offers more privacy and independence than a traditional guest room. These secondary suites are a great solution for aging parents or adult children who want to live near their families.

Historically, the interior mother-in-law suites meant the private living area was not so private. There was often no private entrance. Current State regulations, building codes, and local ordinances require even an attached mother-in-law suite to have all the facilities for independent living.

The quality home design will ensure that you have an exceptional home that allows flexibility for any future potential buyers. If your relative likes to travel for extended periods, you can use this additional space for rental income.

welcoming in-laws

What You Need to Know About Mother-In-Law Suites

A mother-in-law suite is a type of residential unit that is built onto or near an existing home. It provides additional living space, often for extended family visitors or guests.

These suites usually consist of one bedroom and one bathroom, a kitchenette or small kitchen, and come with separate access.

Did you know that over 51 million Americans live in multigenerational households? That was s a 10% rise since 2007 to 2020, according to USA Today. Can you imagine how this trend accelerated since? It’s becoming increasingly common to have multiple generations living together under one roof.

In fact, already in 2019, nearly 20% of Americans lived with multiple adult generations in the same household. This points to a clear trend of intergenerational living worth considering when purchasing your next home.


Types Of Mother-In-Law Suites

When planning a mother-in-law suite on your property, it’s essential to consider the type of addition that best suits your needs. There are four main types of mother-in-law suites: attached, detached, basement, or converted spaces. An attached suite is typically connected to the main home, while a detached suite is built separately, at some distance from primary residence. Both options offer more privacy for your in-laws and can be customized based on their preferences and lifestyle. Basement suites are ideal for homes with basements that have plenty of space and enough ceiling height (typically above seven feet). Finally, a converted garage can also make a great mother-in-law suite.


Regardless of which type of suite you decide to build, it’s important to consider the costs associated with construction and maintenance and local zoning laws. In some areas, a mother-in-law suite may require additional permits and inspections. Always check with a professional before spending any money on design.

Types of accessory dwelling units - detached, attached, junior.

Mother-In-Law Suite Guide: Key Features And Amenities

When planning a mother-in-law suite on your property, consider the key features and amenities that make this space comfortable and livable.


The potential features may vary depending on how much space you have to work with. Common inclusions are:

A separate entrance for privacy

A private kitchenette or full kitchen

An additional bathroom

Ample closet space

Living and dining areas

Air conditioning and heating


Consider investing in amenities like internet access, solar panels, a patio, or even an outdoor kitchen or spa tub. You can even sneak into your own home office. Of course, the more amenities you add, the more expensive it will be to build the suite, but it could offer a greater return on your investment.


Importance Of Accessibility And Universal Design Principles


Due to physical limitations, older adults may need help using standard suites. If you plan to add a suite for your in-laws, ensure the design incorporates universal design principles.


This means including wider doorways and hallways, easy-to-use heating and cooling systems, lower countertops and sinks, and grab bars for support. It’s also essential to consider installing features that can be easily modified as your in-laws’ age. This way, you can keep the home up to date and make sure it’s accessible for years to come.


In addition to accessibility, universal design principles can help you create a beautiful and inviting environment, regardless of age. This includes utilizing natural materials like wood and stone to create a warm atmosphere. You may also consider adding an accessible walk-in shower for your in-laws to enjoy bathing without worrying about slipping or falling.


Granny flats or ADUs are the ultimate problem-solvers! These structures are incredibly adaptable and can transform into whatever you need them to be for any given moment. With the right design, they can provide a perfect set-up for your in-laws while also serving as an additional living space for you and your family. 

Design Considerations for Mother-in-Law Suites


Space Utilization

Before starting a project, consider the available space and how to best utilize it. What is the position of the new structure in relation to the primary house? Is there enough room for a kitchenette or dining area? Can furniture be arranged efficiently? Are there any particular features, such as a fireplace or laundry, that could be included? Make sure the full bathroom is spacious and comfortable.

Universal Design Elements

Universal design is an important consideration when designing a mother-in-law suite. Ensure the space allows easy mobility and access, such as wider doorways and hallways.

Also consider features such as handrails to assist with stability, non-slip flooring, bathroom grab bars, lowered countertops for easier reach, and dimmer switches for lighting control. These elements can make the suite safer and more comfortable for all occupants.

Creating A Separate Living Space

Creating a separate living space for elderly parents can help maintain privacy while expressing individuality. Consider options such as French or pocket doors for defining boundaries between rooms and adding area rugs or furniture to create distinct living spaces within the suite.

On top of that, think about incorporating personal touches such as favorite furniture, artwork, or décor that reflect personality and interests. This will make the space more inviting and enjoyable for everyone. Items of sentimental value make a new home feel special for your loved ones and show that you care.

Incorporating Essential Amenities

Consider the amenities essential for comfortable living when designing a mother-in-law suite. A kitchenette with a sink, refrigerator, and microwave is helpful for basic meal preparation and storage. Check local regulations – some spell out the fridge size and the necessary space on the countertop.

A bathroom should include a toilet, shower/bathtub, and vanity. Depending on the size of the suite, the sleeping space could be an alcove or a bedroom. A living area could be a separate room, an open floor plan, a combination of kitchen, dining, and living areas.

Natural Lighting And Ventilation

Incorporating natural light and fresh air can make the space feel more inviting. Think about adding windows, patio doors, skylights, or solar tubes to bring in daylight and provide views of the outdoors.

Cross ventilation is also important for comfortable living – consider installing a ceiling fan or operable windows to create airflow throughout the suite. This should help to reduce odors and create a more pleasant living experience.

Storage solutions

Regarding storage solutions, there are several options for maximizing space in a mother-in-law suite. Think about utilizing wall shelves or cabinets for organization and easy access. Build additional closets or drawers for clothing and personal items. Also, consider adding seating with built-in storage, such as ottomans and benches, to double up on space-saving capabilities.

modern in-law suite

Building a Mother-in-Law Suite?

Here’s what you should know to achieve creating a functional and welcoming space.


If you’re thinking of adding a mother-in-law suite to your property, there are quite a few details to consider. To ensure you create a functional and welcoming space that meets the needs of any in-laws or other family members that will be living with you, here are some tips to keep in mind:


  1. Communication and Collaboration

It’s important to create a welcoming and comfortable space for your in-laws. To ensure you get it right, involve them in the design process and discuss any needs they may have. This will help ensure everyone is on the same page before construction begins. When I was building my first multigenerational home, I was astonished to learn my in-laws needed separate bedrooms. I did not know the term “sleep divorce” then.


Remember, when building a mother-in-law suite, communication and collaboration are key!


Once you decide to build a mother-in-law suite, it’s important to know what you need in order to do it correctly. Start by finding out what kind of space you have to work with and what modifications need to be done to create the suite. You’ll also want to consider the construction costs and any additional costs you may incur while building the suite. An experienced professional will alert you to potential cost drivers.



  1. Prioritizing comfort and accessibility

When designing your mother-in-law suite, prioritize comfort and accessibility. Choose furniture that is comfortable but also has safety features such as adjustable heights or non-slip surfaces.


Select quality appliances and fixtures that will stand the test of time and provide a safe environment for your family members.


Consider installing safety bars on the bathtub and bathroom wall and adding a kitchen island for extra workspace. Adding special features such as grab bars in the shower or a walk-in closet can also increase the accessibility of your in-law suite.


  1. Personalization and aesthetics

Nothing can replace the feeling of a cozy home, so make sure to add elements to make it feel like one. Personalize the space with artwork, rugs, and other decorations that reflect the individual’s personality and style. This helps create an inviting atmosphere for your family members to enjoy.


  1. Smart Home Technology

Smart home technology can be an excellent addition to any mother-in-law suite. Automation systems can make living in the space more convenient and secure while providing peace of mind for family members who may not always be around.


Start with integrating features such as voice control, automated lighting, and smart door locks into your design. Smart appliances can also provide convenience that traditional ones might not be able to, such as refrigerators with built-in cameras or washers and dryers with Wi-Fi connectivity. These features can make the living experience more enjoyable and efficient.


  1. Safety measures

Safety should always be a priority when designing a mother-in-law suite. Install adequate lighting and grab bars where necessary, as well as emergency response systems such as medical alert systems in case of an unexpected fall or other emergencies. This will help ensure your family members are safe and secure while living in the space.


mother-in-law with a daughter-in-law

Mother-in-law House is an ideal solution for multigenerational families.

Building a mother-in-law suite on your property can be an excellent way to provide comfort and convenience for family members while also increasing the value of your home.


When designing the suite, it’s essential to consider safety measures, natural lighting and ventilation, storage solutions, smart home technology, and personalization and aesthetics.


Do not pick any general contractor. Select someone who has experience building homes. The building process for this MiL suite is the same as for any single-family home. The process is different from a regular kitchen or bathroom remodel.


Considering all aspects of a mother-in-law suite will help ensure that your family member is comfortable and safe in their living space.

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