What Is a Mother-In-Law Suite, and Should You Have One?

Multigenerational living is on the upswing as an increasingly high number of households are embracing cohabitation. The reason could be to fulfill a specific need or simply by choice.

But either way, a 2019 report revealed that 20 percent of Americans reside in the same household with two or more adults, which is a major contrast to 12 percent in 1980. This latest housing trend in real estate has heightened collective interest in a type of household add-on known as in-law suites.

What is an In-Law Suite?

An in-law suite is the name for a small abode that is either part of or attached to a home. It’s often added for the purpose of allowing an older family member to enjoy a tinge of privacy and solitude at home.

An in-law suite is known by many other names, including mother-in-law suites, accessory dwelling units (ADUs), secondary units, granny flats, and ohana units in Hawaii. But no matter what you call them, in-law suite additions typically include a separate area with a bathroom.

These add-ons are usually located in the basement or next to the garage of existing homes. They are very helpful for multiple reasons, and providing a cozy place for an elderly family member is only one of many.

What is the Appeal of an In-Law Suite?

There are a lot of reasons to incorporate an in-law suite into your home. Multigenerational living, particularly with mothers, is on the rise. Currently, over 40% of Americans purchasing a home are contemplating including an older person or adult child as part of their households.

The main allure is the cost savings of living in the same home. It also promotes family bonding as you get to spend more time with your beloved relatives. For instance, Granny may adopt the role of a standby babysitter who spends valuable time with her grandkids.

In other situations, elderly family members might be suffering from a terminal or difficult disease that requires in-house caregiving. By welcoming your family member into your home, you’ll save a lot of money by not having to pay for caretakers or at-home services.

Alternate Uses for In-Law Suites

Home Office: The pandemic has normalized working from home, making the mother-in-law area the best place to oversee a small business or work on your remote career.

Guest Sections: Whenever out-of-town visitors stay with you, an in-law suite is a lifesaver as it’s the most suitable place for friends and extended family members to enjoy their own bedroom and bathroom space. Wouldn't you rather make a memorable impression on your guests than ask them to stay in a hotel? In-law suites can make that possible.

Housing a Grown-Up Relative: Adult children who are working towards financial stability can be housed in your mother-in-law suite until they become fully financially independent on their own. You can also charge your relative a small fee for staying with your relative if you’d like.

Short- or Long-Term Leasing: Many in-law additions are well-equipped living spaces, thereby making them eligible rental apartments that can generate ancillary revenue.

What to Know When Considering an In-Law Suite

With so many options of what you can use an in-law suite for, you’ll need to know what to look out for when creating an in-law suite as well.

Regulation: First, you need to know if you're permitted by law to create an in-law suite. In some regions, zoning laws may prohibit you from adding a supporting property. In places where building the suite is legal, there will still be restrictions regarding the legal size and the purpose of your in-law suite.

Maintenance Costs: We have already provided you with insight into the cost of creating a mother-in-law suite, but your spending requirements won’t stop after the final addition is commissioned. You'll need to include the cost of utilities, like electricity bills and plumbing expenses. Over time, repairs will be necessary, so keep extra cash for that.

Design: You need to create a safe design for your in-law suite, especially if you intend to accommodate an older relative. Consider installing guardrails to prevent the chances of falling or windbreakers if your neighborhood is prone to violent weather.

Are In-Law Suites Legal?

Municipal laws vary when it comes to the legality of an in-law suite and its use. Approach your local zoning office to find out whether installing a suite on your property is permissible.

You'll also need to obtain building permits. Still, there might be some limitations on what can be integrated into the suite. For instance, some municipal laws do not permit in-law suites to contain complete kitchens in an effort to eliminate the risk of stove fires.

Some laws also stipulate that the suite cannot be leased if it is not being used for the purpose of housing a relative. All in all, make sure you’re aware of local laws and abide by the applicable laws before you begin to construct an in-law suite on your property.

Does a Mother-in-Law Suite Add Value?

Buyers are quick to identify the potential benefits of a mother-in-law suite, whether it be for a home office, for relatives, or for making passive income by renting it out for profit. So yes, a mother-in-law suite does add value.

How Are These Suites Configured or Added?

A common way to add a mother-in-law suite is by remodeling a space that is not being utilized. The garage is a perfect example. The garage is either attached to the existing house or detached completely, but either way, it works great as an in-law suite.

You can add extra square footage to the garage if necessary and create a spacious in-law suite from there! Another option is to convert an existing bedroom that offers some sense of privacy, particularly one that is near the back of your house. This opens up more options for design uniqueness and expansion, like adding a door that leads outside or creating a roomy bathroom.

How Much Does it Cost to Build a Mother-in-Law Suite?

When creating an in-law suite, you can expect to spend an average of $32,000 to $63,000. Building a new structure altogether, as opposed to adding an in-law suite to your existing home, can cost upwards of $125,000.

The exact amount of money that it will cost to build a mother-in-law suite will depend on the size you want it to be and what you plan to add to it. The overall expenses will also depend on whether the suite is intended to be used as a standalone structure or an annexation of the existing house.

Different Types of Mother-in-Law Suites

Now that you have a better idea of what it could cost to install a mother-in-law suite, let's talk about the two major types of in-law suites.

Freestanding In-Law Suite

As the term implies, a freestanding in-law suite is a standalone design, meaning this type of in-law suite will be completely detached from your house. This is a suitable option for anyone who wants to offer ultimate privacy to guests. A freestanding in-law suite is expensive, and you may need to spend even more money to modify the existing property so that it accommodates the new sub-unit. Expect to dole out up to $100,000 on a freestanding in-suite project.

Attached In-Law Suite

If you don't have an additional room that can be converted into a secondary unit, you can build an add-on from scratch. Most remodelers debate the benefits of this style as some believe it lowers the risk of violating the structural integrity of the house while others disagree. But either way, the attached in-law suite idea is not as expensive as the freestanding option. Rather, attached in-law suites usually cost anywhere from $30,000 to $60,000 on average.

Common Questions About Buying a Foreclosed Home

Over the course of the building process for your mother-in-law suite, you may consider buying a foreclosed home. Some foreclosed homes are in great shape, while others need considerable work.

With enough money to cover repair costs, you can secure an enviable deal. But first, you need to know the answers to common questions that prospective homeowners ask before buying a foreclosed house.

Are There Any Liens on the Home?

This is a very important question. If there is a lien on the home, it will carry over, meaning once you own the home, the lien will become your responsibility. In other words, the lien will be transferred to you when you purchase the home. The seller is probably selling their home because they want to get rid of the lien. Never omit this question as the answer can make or break your decision to purchase the home after all.

What Are the Previous Issues With This Property?

This is a primary question that yields straightforward answers. Make sure you are informed about any and all issues pertaining to the home’s foundation, problems with neighbors, previous inspections, the age of the roof, fittings, electrical, and plumbing concerns, among other house-related details that you need to be aware of before you buy the property.

What is the Neighborhood Like?

Whether the house you're buying is foreclosed or not, you must do your due diligence by exploring the neighborhood. Find out if there are amenities like parks, centers, schools, or anything else that may pique your interest. Knowing the neighborhood through and through will put you in a better bargaining position. Plus, there will be fewer surprises awaiting you when you move in and turn the house into a home.

Summing Up Everything About In-Law Suites

A mother-in-law suite is a secondary suite that offers a myriad of benefits, like providing the most thrilling live-in for your grandma or helping your adult child as they make their way to financial independence. Just make sure the type of in-law suite that you decide to create is within your budget and that your project abides by local legal stipulations.


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This page last updated: March 21, 2022