The 5 Elements of Perfect ADU Design

We previously covered how to choose the right ADU layout for your project. However, the design process doesn’t stop after you’ve settled on a preliminary layout for your backyard Cottage, in-law unit, granny flat, or rental unit.

Despite being generally smaller than standard single family homes or multi-family apartment units, ADU architecture can be deceptively difficult. Tight spaces and stringent code requirements around living areas can make it challenging to figure out what’s possible in the living space. Minix Home Design Manager and small space enthusiast Manon Paquet joins us to provide her thoughts.

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Effective ADU Design: 5 Keys to Success

High-quality and effective ADU design combines a few key elements that we’ll cover today:

  • Daylight
  • Privacy
  • Storage
  • Plumbing Blocks
  • Focal Points

Let’s look at how each of these keys impact your ADU’s design and development.

Key 1: Daylight in the ADU


ADU spaces are oftentimes small, tucked away in a backyard, and can be surrounded by neighboring homes, trees, and fences. However, no matter the surrounding conditions, optimizing a design around daylight can be a real game changer for your ADU.

My main design focus is to ensure each room gets light from at least two directions. That can be two exterior walls, interior openings towards brighter areas of the ADU, or skylights.

An important consideration when choosing window placement is the impact on comfort and energy use. For example, south-facing exposure provides warm, enjoyable, ambient light throughout most of the day. However, the same large south-facing openings in a hot climate will bring in more heat and drive additional reliance on air conditioning systems.

North-facing light, on the other hand, will be softer and cooler with fewer glare issues, but will bring in much less direct light and generally be significantly more diffused. Because of the large impact in the feeling of the space, daylight exposure should be a driving factor in early ADU design and continue in discussing the location and sizing of exterior openings throughout the design development process. The Minix Home design team is well versed in these choices and trade-offs and is happy to discuss your ADU design with you.

Key 2: Privacy for Your Accessory Dwelling Unit

After discussing daylight, it is also important to consider privacy as a balancing factor when thinking through windows, doors, and other openings.

As lovely as large windows with outdoors views can sound to most of us, it is less appealing when it showcases your neighbor hanging out laundry, taking out the trash, or doing a U-turn in the driveway as you cook dinner. Privacy is a key consideration for ADU design. Depending on your use case and property layout, determining the right level of visual separation between the main home and the new unit will be crucial to ensuring your ADU fits your long term needs.


At Cottage, we aim to strike the right balance between fully secluded and fully integrated with existing and neighboring structures. We take advantage of tips and tricks, such as sizing and locating windows, selecting their opening mechanisms, and choosing particular glazing types ranging from obscured frosted glass to fully transparent. These design development discussions also help ensure the design and ADU will stand the test of time: through changes in use cases, new tenants, and a potential future sale of property.

Key 3: Storage in Your Housing Unit

In designing tight spaces, it can be tempting to strip down walls and other layout elements to the bare minimum and imagine larger open living areas. However, we make sure that each ADU offers enough storage space to accommodate the resident’s needs comfortably.

Various areas of the home can be utilized for storage. Bedroom closets are common storage features, while entry coat storage and bathroom or linen storage are often overlooked. Kitchen layouts should also be efficient: in small spaces, every linear inch of cupboard counts. The Cottage Design team avoids dead corners and maximizes unoccupied spaces such as utility closet, attics, under-counter areas.

Your ADU may not be always be used for tenants downsizing from a single-family home to a small studio, but it should still be able to store a lifetime of treasures regardless of occupant.

Key 4: Plumbing Blocks for Your ADU

While plumbing may sound like more of a technical consideration for your ADU, it can still impact the design and quality of your space. In laying out the elements of your ADU, the Minix Home team places a strong emphasis on optimizing “Plumbing Blocks”—that is, kitchens, bathrooms, and other rooms and appliances that require water or sewage piping.


We work to find alignments that reduce the length of plumbing spans. In doing so, we avoid unnecessary utility dead-ends around the unit, and can make the most of shared plumbing walls (for example, the wall between a kitchen and bathroom) or continuous “wet walls” (for example, a bathroom and kitchen with faucets placed along the same wall).

Most importantly for you, designing for these considerations up front saves you both construction time and money! Optimizing plumbing blocks allows efficient space design, reduces plumbing material and installation costs, and leaves room and budget for features that you’ll love and see every day.

Key 5: Focal Points for Your ADU Design

Last but not least, all great ADU designs should have stunning visual highlights. While luxury finishes and custom millwork do not fit in most construction budgets, it doesn’t cost extra to pay careful attention to details where design can yield great “space moments” that the resident or renter will feel every day walking through the unit.


At Minix Home, we believe small and large ADUs alike should feel like luxury. And part of this comes from putting ourselves in your shoes, imagining what walking around the space is like. We don’t want to enter and face a stackable washer and dryer. We don’t want to go to bed staring at a water heater closet. We don’t want to cook while staring at a blank wall.

We do, however, want to locate typical eyesores away from the eyes, make the most of every little nook, highlight a great view with a picture window, emphasize wall space for art or storage, and design comfortable, visually-pleasing, and quality housing for everyone.

The Keys to a Successful ADU Design

In her extensive time as a Studio Designer then Design Manager at Minix Home, Manon has lent her expert touch to many different types of ADUs. From garage conversions to retirement units, small studios to spacious 2-bedrooms, our design team’s experience spans the full spectrum of custom ADU designs and uses.

The Cottage team believes in designing your stick-built ADU in a smart, cost-effective way to give you the best bang for your buck while matching your needs, budget, and use case(s). Click the “Get Started” button on the top right hand corner to get a Free Consultation and Estimate today!

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