8 Tips to Consider When Building an In-Law Suite

Jacqueline Zenn
Written by Jacqueline Zenn
Updated October 11, 2021
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Building an in-law suite is a wonderful way to upgrade your home, and these tips will ensure that your addition serves your needs

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If you are planning an in-law suite addition or upgrade, there are many elements to consider before you begin. Follow these tips to design an in-law suite that your family will enjoy, adds value to your home, and enhances your lifestyle. 

What You Should Know Before Building an In-Law Suite

Before you renovate an existing room or build an in-law suite as an addition to your home, you should consider these key aspects.

1. Location

If you are building an independent or free-standing structure, there are many factors to consider before starting construction work. The same goes if you are remodeling an existing basement or turning a floor of your home into an in-law suite, although the construction costs for the latter will most likely be lower than for a completely new build. 

2. Building Ordinances and Zoning

You’ll need to check out local building codes and regulations after determining whether to build a new structure on your property or utilize an existing space as a separate unit. You may also want to ensure that the in-law suite’s utilities are separate from the main house, which is particularly essential if you plan to rent the unit out in the future. 

3. Timing and Construction

It’s always a good idea to assume renovations will take longer than the original timeline, and this is also true when building an in-law suite or addition. If you plan on your older family members living with you eventually, start planning as soon as possible. You’ll want the in-law suite ready to go before you need it and while your parents or in-laws still live independently. You can always rent out the unit in the meantime if you complete it early! 

4. Accessibility and Aging in Place

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Finding a contractor who can handle building an in-law suite to your specifications and understands your accessibility requirements is a critical step to complete before you break ground on your in-law addition. 

For instance, consider any disabilities of your future residents. Do you need a walk-in tub, lowered counters for wheelchair users, or other unique features? Does the space need to be wheelchair accessible? This means you’ll need wider doorways and hallways, grab bars in the bathroom, lower countertops and cabinets, and more room to maneuver in general. 

Before you sign off on architectural or building plans for an in-law suite or addition, consider these needs. Work with a contractor or architect who is a Certified Aging in Place specialist and knows how to make the appropriate safety modifications for elderly or disabled individuals. This will help to ensure that your parents or in-laws can live comfortably and happily in their new home.

5. Necessary Features

Aging in place is becoming increasingly common, so if your parents, in-laws, or other family members are unable to live alone but are still somewhat independent, an in-law suite in your house or on your property can be a good choice. Moreover, adding a complete in-law suite with its own kitchen or kitchenette and full bath can increase your property value. You can even rent out the in-law suite in the future if you wish.

6. Separating Utilities From Your In-Law Suite

While the original reason for your addition is a home for your in-laws, it can be a great option for adult children, disabled family members, or friends in transition. You can also rent out the in-law unit for some extra income. 

Suppose you plan on renting out the suite or otherwise separating it on your household budget. In that case, you’ll want to ensure it has its own meters and utilities set up so you can bill or track associated costs appropriately.

How to Build an In-Law Addition

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Hiring a contractor (or a whole team) and architect near you who have experience in designing in-law suites and understand the unique requirements is perhaps the most important step towards successfully adding another residential unit to your home. Check out their previous work, get references, and search for reviews online before signing on the dotted line, and be sure to get multiple estimates from contractors and architects who have done similar work in your area.

1. Size of an In-Law Suite

Approximately 500 to 700 square feet is a good size for an in-law apartment or addition. Think of a studio apartment and plan accordingly–at the very least, you’ll need room for a bed, some living space, a bathroom, and a kitchenette with a small dining area. If your in-laws or parents are living with you, they likely will be using the main house as well, so they will have some additional room and storage space there. 

2. Cost of an In-Law Suite

The price of an in-law suite varies greatly depending on whether you upgrade or enhance an existing area of your home or add an entirely new room or freestanding building.

That said, building an in-law suite costs around $44,000 for an additional bedroom and bathroom but can increase to over $100,000 for a fully detached structure or an apartment over a garage.. 

When you are adding on to your home, you’ll likely need a team of professionals, including an architect, roofers, electricians, plumbers, and more, along with general contractors and labor.

3. Privacy Considerations

Privacy is also an important consideration for your in-law addition. While your parents or in-laws may not live totally independently, they still need personal space. Building a freestanding structure on your property or putting the in-law suite on a separate floor or opposite side of the house can be an excellent way to balance privacy and family time

Can I Build an In-Law Suite Myself?

Even if you are super handy or skilled at DIY projects, building an in-law suite is complex and is not really a task for a weekend warrior. This is because there are many complicated factors involved, such as wiring for electricity, installing plumbing in the kitchen and bathroom, taking care of climate control utilities like heating and air conditioning, and otherwise laying the groundwork for another residential unit. 

That said, once the foundation of the in-law suite is in place, you could likely handle things like painting or finishing the flooring to save on costs. If you are remodeling an existing unfinished space into an in-law suite, you may also be able to tackle parts or all of the project yourself depending on your DIY skills and inclinations. 

Will an In-Law Suite Increase My Property Value?

Adding an in-law suite can make your home more appealing and increase your property value. After all, even if potential buyers don’t have parents or in-laws to move into their home, an additional unit can benefit a disabled family member, an adult or older child who wants their own space, or a friend who needs a transitional living situation. An in-law unit can also be an excellent source of rental income. 

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