13 ADU Design Ideas to Maximize Your Space Inside and Out

May 23, 2022

On average, a California accessory dwelling unit (ADU) is 615 square feet. Some ADUs, though, can be as small as 300 square feet or as large as 1,400. No matter which size is best for your needs, ADUs leave you with plenty of indoor and outdoor space to decorate and design as you see fit. Below are some ADU design ideas that can maximize your place and make your space feel like home.

How do you maximize space in an ADU?

Windows large enough to let in ample natural light are a great start to make the most of your ADU space. So too are strategic mirror placements to reflect this light. Built-in storage solutions can cut down on clutter that could make your ADUs look tiny and cramped, too. You may also want to turn to furniture that only expands when you need it, like a sofa with a pull-out bed or a table with drop-down sides.

No matter what, though, your interior design should go hand in hand with your ADU’s house plan and layout. For example, if your ADU is limited on windows, crowding your sill is basically crowding your unit. 

What else should you keep in mind when maximizing space in an ADU?

When you’re maximizing space in your ADU, you’ll fare best if you consider your ADU’s purpose. After all, a home is decorated differently than an office space. You should also consider both its interior and exterior alongside its attachment (or lack thereof) to your single-family home. The following tips should help you out as you decide which ADU design ideas do and don’t work for your space.

Why you’ve built an ADU

The best ADU design ideas for your space will hinge on its purpose. For example, an office ADU might not need as much exterior landscaping since you’ll mostly work indoors and you’re not likely to host clients at your home office. If you plan on renting out your ADU for short-term stays, you may want decor to be more generally pleasing and less personalized than if you plan to live in the ADU you build.

Tiny home interior design.
Photo by Andrea Davis on Unsplash

Your ADU type

Accessory dwelling units typically fall into one of three major categories: detached ADUs, attached ADUs, or interior conversion ADUs, which can also be considered attached ADUs. 

Detached ADUs are smaller homes not connected to the main house on the property. That means they require extra exterior care, such as landscaping or outdoor furniture needs. Landscape decorating becomes significantly more important for these ADUs. An attached ADU, on the other hand, won’t have these needs.

Your ADU size

Interior conversions like a basement or attic ADU attached to the main residence are inherently size-limited. That limit can present unique challenges. For example, sliding glass doors might be infeasible in a basement ADU, which might also not get enough light for plants to survive. That eliminates two great ADU interior design ideas right off the bat. This also means you’ll have to make practical considerations for the furniture and decor you place in your ADU. A smaller space won’t allow for as many items that stand on the floor, for example, but may be better for wall hangings.

The 13 best design ideas for the ultimate ADU

The below ADU design ideas can help you achieve the ultimate “granny flat” (another name for an ADU). You’ll impress potential tenants, guests, and even yourself when you step into your fully furnished unit. 

1. Increase natural light

When working in a smaller space, natural light is your best friend. So open up the main areas like the living room and bedroom with large windows that bring the outdoors to you. The sun will shine right through during the day, making your ADU appear more spacious. This tip is especially important if you plan to rent out your ADU. Most tenants seek as much space as possible for their dollar, and natural light can make a place feel bigger than it is.

2. Incorporate plants with large leaves

Plants are another way to cultivate an inviting and open space that won’t feel overly stuffy. They bring the outdoors indoors for that ultimate tranquility. Carefully placed greenery with larger leaves can also trick the eye by playing with the proportions of a space. For example, place a potted plant in the corner of the living room next to the couch. The larger leaves will eliminate negative space without adding to clutter. 

Large leaf plants in a living room
Photo by Spacejoy on Unsplash

3. Use light-colored furniture and walls

The trick with making a smaller space feel larger is to make it seem more open and airy. Upholstered furniture with busy prints or dark colors won’t help on that front – it’s just not as reflective. Off-white and light gray furniture is a better bet, especially against white or light-colored walls. That’s because bright walls are reflective, which can really help that natural light shine. Couple that with similarly-colored furniture, and you can more easily create the illusion of openness. 

4. Avoid clutter with built-in storage

Maximizing space means avoiding clutter at all costs. Namely, a well-designed ADU should follow the golden rule of “a place for everything and everything in its place.” Built-in storage units and shelves can help – they give everything a place to be neatly tucked away, and you won’t need to buy additional floor-cluttering furniture to store your things. Spacial ADUs, for example, come with bespoke wooden built-ins for all your storage needs. 

The idea of downsizing might be intimidating at first, but the right storage makes a huge difference. It allows people to keep items that aren’t in their everyday rotation without crowding their space. Plus, when designing an ADU, you can include furniture with built-in storage to maximize every inch of space. Keeping spare bedding and blankets tucked away when they aren’t needed can make your space feel less cramped – and all the more open.

5. Add mirrors

A carefully placed mirror can trick you into thinking that a room continues well beyond its actual square footage. That’s because they reflect light and the view in front of them, leading you to perceive a larger room. A mirror next to a window point is a great ADU design idea, as is angling your mirrors toward a focal point. At that angle, your mirror can more effectively improve the illusion of larger spaces. 

6. Select landscaping proportional to your ADU

With a detached ADU, you’ll have more exterior elements to consider – landscaping, the entryway, the path to the entryway. You can make the unit feel more inviting with tapered landscaping that suits the size of your backyard cottage. A walkway with perfectly sized shrubbery is a great way to work with the space. 

Row of flowers
Photo by Matt Chen on Unsplash

7. Install a sliding glass door

The theme of mixing the outdoors with the indoors is key for maximizing space. That’s an especially great ADU design in California. The beautiful weather can help you combat that cramped and cluttered feeling with easy access to the great outdoors. And you don’t always have to actually go outside to counter your clutter. A sliding glass door lets in tons of natural light during the day. And if you do need a burst of fresh air, just slide the door open. 

Spacial’s one-bedroom ADUs include an eight-foot tall sliding glass door in the living room. That means your ADU will always come with this light- and space-boosting ADU design idea. 

8. Use furniture with exposed legs

With the right furniture, you can add depth and dimension to your ADU. Furniture that’s low to the ground and features exposed legs can offer the illusion of more space. The open space underneath your furniture can make your space appear larger and cleaner. Furniture that’s lower to the ground is also further from your ceiling, which can make your ADU look taller and larger. 

9. Keep windows clear of obstructions

Your windows are a pivotal part of your ADU design. They’re maybe the most important way that interior designers open up a space with natural light. That natural light can’t quite make it into your ADU if there’s anything blocking the view inside or outside, including dark shades or blackout curtains. Keep the windows clear so they can live up to their full potential and extend your ADU beyond its walls.

10. Install a front deck

Incorporating a well-cultivated outdoor space can help you further maximize your space. For example, a front deck as you step out of your sliding glass shows space beyond your four walls. That space, though not inside your ADU, is clearly part of your unit. That can help you subconsciously perceive your ADU as larger in size. 

11. Stick to light fabrics

Darker fabrics absorb light, and that goes against the open and airy effect you’re trying to create. That’s why lighter fabrics like linen are a summer staple – and they can be year-round components in your ADU too. Linen in a gray, light green, or similarly breeze color is effortless decor and it can give your ADU a greater sense of comfort and openness. 

White couch with light fabrics and textiles
Photo by Taylor Hernandez on Unsplash

12. Expand your space with outdoor furniture

Furnishing the outdoor space around your ADU gives anyone living there somewhere else to go when they need a break from the great indoors. A deck with a table and chairs essentially expands your ADU floor plan without actually adding another room. It opens up possibilities for hours spent reading in the sunshine or working outside. It means more ADU space to use, which in turn can make your ADU feel larger.

This blend of indoor and outdoor living can make an ADU on your property in a region like the San Francisco Bay Area especially appealing. Not that the Bay Area is always sunshine and rainbows, but the weather is often just right for a relaxing afternoon outdoors. Outdoor furniture around your ADU can help you show the maximum potential of this extra square footage – it’s not just a smaller home or workspace. That can sway certain buyers if you sell your property in the future. 

13. Include a solar light path to your ADU

A solar light path can make it easier for you, your family, your friends, or your tenants to get to the ADU at night. It’s environmentally friendly since it’s powered by sunlight during the day, which leaves enough energy to light up the way at night. Spacial units include a full solar PV system installed on the roof so you can pave the greenest path forward. 

Make the most of your ADU with Spacial 

Studio ADU by Spacial
Photo by Spacial

With high ceilings, a sliding glass door, windows, built-in storage, and green features, your ADU design will be at its best without any additional planning or designing by you. Spacial’s studio and one-bedroom Bay Area ADUs provide all this and more. Our goal is to create spaces that you can enjoy for a lifetime. All you do is add your personal touches – we take care of quite literally everything else.

At Spacial, we can install a move-in-ready ADU on your property in under a year. With our West Elm partnership, we can fully furnish your ADU with your input, making the transition from installation to move-in especially quick. We also take care of everything from zoning and permits to insulation, drywall, and kitchen appliances. When you choose us, you can trust that we’ve worked out everything you’ll need to cultivate an open and inviting space. 

It’s our mission to make expanding your space – and your life – as easy and quick as can be. Contact Spacial to learn how we can get you started on building an ADU with room for a whole lifetime ahead.