How To Build The Perfect In-Law Suite

An in-law suite (sometimes called a mother-in-law suite) or accessory dwelling unit (ADU) is an excellent addition to your home if you want more space. You might want to build an independent space for your parents or other relatives who may need some extra support and want to live as independently as possible. Or you might want some extra space for guests.

Accessory dwelling units are a great choice because they can be constructed in your backyard or on any other open land you might have. You can also convert your garage or attic to add more space to your home.

But creating the perfect in-law suite is a big project, with lots of things to consider. In this post, we’re going to take you through everything you need to know about building an accessory dwelling unit on your property.

When you're building an in-law suite, you’ll be building it with a specific person in mind. For example, one or both of your parents might be coming to live with you. If this is your plan, you should talk to the people living in the new space when making your plans.

It might be your property, but this new space will soon become their home. They should get to have a say in what they need and how the space will look.

Of course, you can still have your say. For example, you might want the ADU to blend in with your existing home design, and you’ll have the final say on where and how it is constructed. Our best advice is to work together with all the relevant people to come up with a plan that works best for everyone.

Before you go too far with planning your in-law suite, you should think about how much you can afford to spend. Whether your budget is modest or large, you should make a plan that will work for you.

If you're looking to save money on the project, you can save by making your unit smaller, looking at prefab solutions, using affordable materials, and more.

Even if you have more money to spend, it’s always a good idea to understand the costs involved with construction projects and carefully track your budget.

A site plan gives you an overview of your existing home. This is a must-have before you start planning for your expansion. It will help you identify the best place to build your in-law suite and tell you the dimensions of your property.

You might also need a site plan if you need to apply for a building permit before you begin construction. 

Next, you’ll have to decide how you want to add an in-law suite to your property. An ADU is often a free-standing structure that might stand in your backyard or other available spots.

However, in-law suites don’t have to be new, free-standing structures. There are alternative ways to add an ADU to your home, including converting an existing space like a garage. You could also build an addition onto your existing home, which could serve as your ADU.

You might know that you want an in-law suite, but there's a lot to think about in your design. Before you set anything in stone, it's good to get some inspiration and find some ideas.

Take a look at some examples of ADUs to see what you can do with your available space. Ideally, an in-law suite will provide everything that you would need in a home. It should have a bedroom or sleeping area, living space, kitchen, and bathroom. A quick look online can give you some great inspiration for designing your in-law suite inside and out.

If you're planning to have an older relative move in, you’ll need to make the space accessible. People often need more help with mobility as they get older, so it makes sense to add accessible elements to your design. This can include things like wider doorways, grab bars, and an adapted bathroom.

Don’t forget to consider what will happen to your ADU if the intended occupants don’t use it. Maybe they're not ready to move in yet, or maybe they will eventually move into different accommodations. Try to create a flexible design that can be used for multiple different purposes.

You will need to consider some essential features when designing your new ADU. Make sure you plan for some of the fundamentals, such as proper ventilation and exposure to natural light.

In-law suites tend to be small, so you should also think about how you can maximize the space. One way to do this is with high ceilings. It might not give you more floor space, but it does give the impression that your space is bigger.

And don’t forget about storage! Your ADU needs plenty of storage if you want it to be suitable for anyone to live there. Moving into an in-law suite might require getting rid of some clutter, but there still needs to be space for personal things. Adding closets, built-in shelving units, or storage cupboards to your design can help ensure your ADU has enough space to stash everything away. 

You’ll need some architectural drawings before you get started with construction. These days, it’s easy to find project plans online. One option is to find some project plans online. You can browse plans and buy some that you like that fit your available space.

Or, if you want a more custom design, you can hire an architect to design an in-law suite from scratch. Even if you choose to use existing plans, an architect can adapt them and make adjustments to help the plans suit your needs and fit the space you want to use.

Choosing an architect might seem a little overwhelming at first. Here are some tips to keep in mind when choosing an architect:

• Check their portfolio: Look for architects who have designed this kind of space before. Their portfolio of past projects can give you a sense of their style and what you can expect their design to look like.

• Ask for recommendations: Do you have friends or family that have built similar home additions? Now is a great time to ask them for their recommendations. They might know an architect who is perfect for your project and can tell you what working with them is like.

• Try a design-and-build service: Design-and-build services take care of the whole project. This can be a more cost-effective option and save a lot of time. Beyond the design phase, these services already have a construction team, so you don't need to spend time looking for contractors. This option might not be for everyone, but it is one way to ensure a smooth process.

If you don't want to spend the time finding an architect and designing your ADU, you could consider prefabricated designs. A prefab design will allow you to choose a layout you like and quickly install it on the site where you want it.

You can usually customize prefab designs a certain amount, so you’ll have some control over the final product. One of the benefits of a prefab design is that it makes it easy to control the costs. Installation is easier, too, and it can also often be easy to take apart if you decide you no longer need it.

You will need to make sure that your new in-law suite meets any regulations or building requirements. These can be government regulations or homeowner’s association (HOA) rules. You may need to follow regulations relating to the size of your ADU and its features and materials. Check with your local authority to see what regulations you need to follow.

Once you have the design of your new unit planned out, you will need to find the right contractors. Your architect might be able to help you since they have probably worked with different contractors and can recommend builders for the job.

Just like when choosing an architect, you can also ask friends and family for recommendations to help you find a contractor. You could look for a contractor specializing in ADUs, although it isn't necessarily a priority. A look through a contractor’s portfolio can help you decide if you like the quality of their previous work. And don’t forget to check out online reviews from previous customers.

Want to learn more about hiring a contractor? We’ve put together a handy checklist to help!

Once you’ve hired the perfect contractor, it’s time to start construction. Building an in-law suite or accessory dwelling unit is like building a house on a smaller scale. The My Site Plan blog is a great place to start if you want to read up on all things construction, home additions, and design.

And if you need a site plan for your upcoming in-law suite project, My Site Plan can help. We can help you put together permit-ready plans and get your project in motion. Learn more about our site plan options.