The Story Behind the Mother-in-Law Suite

Evelyn Long

Feb 19, 2021

what is a mother-in-law suite

What is a mother-in-law suite? The term refers a guest house or apartment space attached to a dwelling. Also called a granny flat or in-law suite, the size varies depending upon local regulations. Traditionally, these were installed so extended families could move in with loved ones and still have some separation and independence.

If you’ve heard more about in-law suites now than ever, there’s a reason. More households are turning to multigenerational living, with about 24% of those between 55 and 64 living with their children. Plus, some housing activists see additional units as part of a solution to urban housing shortages — opening up more homes on previously single-family lots.

How did this trend come about? While there is no official single story about mother-in-law suites, there are some common jokes about mothers-in-law that make you realize why people build a granny flat instead of just using a spare room. Here’s what you need to know.

Reasons to Build a Mother-in-Law Suite

If you’re considering building a mother-in-law suite or choosing a home with one attached, there are many benefits to adding this detail to your home:

1. Overcome Rising Housing Costs

In April 2020, $246,334 was the forecasted price for the average home in the United States. Obviously, the cost varies widely depending upon location and demand in your area — but the truth remains that homeownership can be a stretch for many households.

Pooling resources with the in-laws is a smart way to afford the home you want while still giving everyone their own space. Elderly family members with income limitations and young families can reside together instead of fending for themselves in the real estate market.

multigenerational family in an in-law suite

2. Help the Older Generation

As people age, they may need help with daily chores, such as mowing the lawn. Perhaps they can live on their own but need someone to check in on them occasionally.

A granny flat offers the convenience of having family on location to provide support to elderly family members. This can also cut down on the cost of alternative solutions, like assisted living, which can often be challenging for families to financially support.

3. Add Rental Revenue

This is where the concept of an in-law suite intersected with discussion around ADUs more generally. Your mother-in-law suite doesn’t necessarily have to house your family. You can also rent the space out to a local tenant, providing additional housing on your lot while making up some of the costs of your mortgage.

Since the in-law suite likely has a different entrance, you can keep living areas completely separate. Many people add a sturdy door between the main house and the add-on. You can then lock the door for added safety. Of course, as with any home rental, you will want to engage in a vetting process to make sure you and your tenants agree on the basic courtesies and laws of sharing a lot.

4. Increase Your Property Value

Another argument for this addition is that in-law suites are desirable. Around 33% of house hunters say they’ll pay up to $3,000 more for a home with a bonus apartment. You’ll gain the added value of the square footage plus extra money for having an independent space.

5. Invite Clients to Your Home Office

If you run a home-based business where you have clients see you, you might not want them in your actual home amidst your personal belongings.

An in-law suite affords the opportunity to have customers visit you via a separate entrance and in a professional space. You can use this type of space for salon services, accounting, construction meetings and any number of other business purposes. 

What is a Laneway House?

Although traditionally, mother-in-law suites are an addition to an existing structure, they can also be a detached space on the same property. Think of them more like a guest house. You’ll still save money as you already own the land and likely have existing hookups. 

Made popular by the trend in Vancouver, the Laneway House is one option for a separate space. These dwellings are small. Most Laneways are between 600 and 800 square feet and have one and a half stories with one or two bedrooms and one bathroom.

A stand-alone structure may cost a little more to build than an addition, but you gain extra privacy. The size of the quarters and building costs in your area determine how much the in-law suite costs. 

One limitation for homeowners considering a Laneway House is zoning regulations. Many U.S. cities, facing urban housing crises, are debating current zoning laws to find more opportunities to provide homes on existing land. Research your municipality and state regulations to get a feel for what this discussion looks like in your location.

What is a Mother-in-Law Suite?

Whether you’re interested in multigenerational living or taking in additional rent payments, there’s a lot to love about the in-law suite. Your reasons for building a granny flat may vary widely from another person’s.

The story behind the mother-in-law suite is an interesting one. In years to come, the trend is likely to continue to grow in popularity for American homeowners looking for different housing solutions for their families.

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