ADU Design Ideas That Maximize Space and Comfort

ADU design ideas are essential for creating a functional and comfortable accessory dwelling unit. These compact living spaces, also known as granny flats or secondary suites, are becoming very popular in many cities across the US. That’s because they can be used for a variety of purposes in residential properties. With some smart planning, you can maximize the space and comfort of your ADU, turning it into a cozy and efficient living area.

In this guide, we’ll examine effective design approaches that can help you maximize your limited space and boost the overall livability of your ADU. We’ll cover various design ideas, including clever storage solutions and innovative layout designs, to help you create a practical and inviting space.

ADU Types and Design Considerations

Before we get into specific ADU design ideas, let’s quickly go over the different types of ADUs and the design aspects of each. ADUs, or Accessory Dwelling Units, are basically secondary homes on the same property as a regular single-family house. You can rent them out for rental income, use them as a home office, or house family members, such as elderly loved ones or adult children.

• Detached ADUs: These are standalone units that are physically separate from the main house. They offer the most privacy and independence, but you have to factor in things like access, utilities, and how the ADU fits with the rest of the yard.
• Attached ADUs: These are connected to the main house through one or more walls. They can be a converted part of the house or a brand-new addition. When designing attached ADUs, make sure they fit well with the main house while still giving both units their own privacy and functionality.
• Garage Conversions: Turning an existing garage into a livable ADU is common, especially in cities where space is limited. When designing this type of ADU, consider insulation, ventilation, and creating a separate entrance while preserving the exterior aesthetic of the property.
• Basement Conversions: Using a basement for an ADU means dealing with natural light, ventilation, and moisture control. You also have to make sure it meets all the structural and safety requirements while still being a comfortable, usable space.
• Internal ADUs: These are ADUs built inside the main house itself, such as attic conversions or rearranging existing rooms. Designing these types of ADUs means making the most of the existing space, keeping both the main house and ADU private, and following all the building codes for separate living units.

Innovative Layout Approaches to ADU Design Ideas

To truly make the most of your ADU space, think outside the box with these creative layout ideas:

• Open-Plan Living: Combine your living room, kitchen, and dining area into one large, open space. This setup lets in more light and air and also makes your ADU feel bigger and more spacious.
• Multi-Functional Spaces: Design rooms that serve more than one purpose. For example, turn your home office into a guest bedroom when needed by using a fold-up bed, a sleeper sofa, or a fold-out table. This way, you can use every inch of your ADU efficiently.
• Custom Storage Solutions: Opt for custom-built cabinets and closets that fit perfectly into your ADU. They can include wall-mounted shelves, drawers, under-bed storage, and organizers that suit your storage needs. These can help keep your space organized and clutter-free.
• Smart Use of Corners: Use corners wisely, especially with furniture pieces like a corner desk that maximizes workspace without taking up too much floor space. A storage bench in a corner can provide seating and extra storage for blankets or other items.
• Raised Sleeping Areas: If you have high ceilings, it makes sense to add a raised sleeping area. This clever design can open up more floor space. It can be a great choice for a studio or small ADU, where it’s essential to make the most of every square foot.

Interior ADU Design Ideas for Specific Rooms

• The Bedroom: Efficient storage is important in the bedroom. Instead of letting all that space under the bed go to waste, consider using it for handy storage bins or drawers. That way, you keep the room tidy and organized. For added flexibility, you can use a bed that can be folded away when not in use. This turns your bedroom into a multi-purpose space, like a lounge area or a small office.
• The Living Room: For the living room, focus on versatile furniture pieces that serve double duty. Sofa beds and storage ottomans are great examples ― they provide extra seating and storage in one.
• The Kitchen: In the kitchen, opt for compact, space-saving appliances that still deliver the functionality you need. Be sure the kitchen allows for better workflow by strategically placing the sink, stove, and fridge in an efficient layout.
• The Bathroom: Make functionality a priority when it comes to designing your ADU bathroom. Go for a walk-in shower instead of a bulky tub to save space and improve accessibility. Floating vanities are another smart choice; they create the illusion of more space while offering extra storage underneath.

Tips for Small ADU Design Ideas

ADUs can be as small as 150 square feet in some places like California. This is especially true for interior ADUs. But having a compact ADU doesn’t necessarily mean living in a tight, uncomfortable space. You just have to make every inch of the tiny space count. Here are some ideas to help you do just that.

• Get Creative with Vertical Space. Consider installing tall shelves to make the most of your floor space. Besides giving you ample storage, it draws the eye upward and makes your small space feel larger. You can also free up valuable floor space with hanging organizers and hooks on walls to store items like pots, pans, or even bikes.
• Consider Space-Saving Doors. Swinging doors take up precious rooms when they open, especially in small ADUs. Opt for sliding doors that glide along tracks to save space. For closets, bathrooms, or pantry areas, go with barn or pocket doors that “disappear” into the wall when open. Aside from being practical, sliding doors add a modern, stylish touch to your secondary suite.
• Go with Minimal Designs. Keep your small ADU clutter-free with a minimalist approach. Choose multi-functional furniture, such as a bed with built-in drawers or a dining table that folds down when not in use. Limit the decor to essential pieces that reflect your style without crowding the space.
• Use Natural Light. Brighten up your small ADU with large windows that let in natural light. Big, floor-to-ceiling windows let in plenty of sunlight and make the space feel bigger. If possible, add sliding glass doors that lead to a garden or patio to create a nice flow between your indoor and outdoor areas.

Universal ADU Design Ideas

Using universal designs in your ADU makes it easy and comfortable for everyone to use, no matter their age or ability. Here are some key ideas:

• Easy Access: Wider doorways and no-step entries can make it easy to access your ADU. This helps older adults or people with mobility issues and makes the space safer and more welcoming for all guests.
• User-Friendly Features: Choose fixtures that are simple to use. For example, install lever handles instead of knobs, pull-out cabinets, and adjustable shelves. These features are designed for people with different levels of strength and manual ability, making the space comfortable and easy to move around in.
• Comfortable Bathrooms: Install grab bars in the shower and near the toilet to help with stability. Instead of a tub, a walk-in shower is usually a better choice to make getting in and out of the bathroom easier.
• Accessible Kitchens: Use pull-down shelves in cabinets so everything is within reach. Lower the countertop height in some areas to accommodate those who use wheelchairs or find it hard to reach high surfaces.

Optimizing Backyards With ADU Design Ideas 

Here are some easy ways to make your backyard ADU more comfortable and attractive:

• Green Roofs and Walls: Besides having a nice look, green roofs and living walls also help with insulation. They can keep the ADU cooler in summer and warmer in winter.
• Outdoor Living Spaces: Add a small patio, deck, or garden to your ADU. These features provide a place for anyone occupying the unit to have a relaxing outdoor area.
• Eco-Friendly Features: To make your `ADU more eco-friendly, consider solar panels and energy-efficient appliances.
• Privacy with Landscaping: Use plants, fences, or hedges to create a private space around the ADU. This will make the space feel separate from the main house and neighbors.

Make Your Project Simpler With Pre-Approved ADU Plans

Dealing with the design and approval process for an ADU can be tricky, but using pre-approved ADU plans can make things much simpler. Here’s how they can help:

• Speed Up the Approval Process: Since these plans are pre-approved, they are usually approved a lot quicker than custom designs. This helps you get your project started sooner.
• Cost Savings: Pre-approved plans usually cost less than hiring an architect for a custom design. They also reduce the risk of expensive design changes during approval.
• Variety of Designs: These plans are available in various designs created by professionals, so it’s easy to find one that fits your needs and style.
• Simplify Compliance: Using a pre-approved plan ensures your ADU meets local rules, which means fewer problems during construction.

Check out our pre-approved ADU plans so you can design your secondary suite to meet the zoning codes and building requirements in your area.

How to Get Funds for Your ADU Project

Building or renovating an ADU can cost a bit, but there are plenty of ways to get the money you need to help make your project a reality. Here are some options to consider:

• Home Equity Line of Credit (HELOC): A HELOC lets you borrow money using the value of your home as collateral. These lines of credit usually have lower interest rates, making them a popular choice among homeowners looking to build or fix up ADUs. 
• Home Improvement Loan: This loan is great for funding specific home improvement projects, such as renovations, repairs, and upgrades. It’s a good choice if you already have an ADU and need money to update it the way you want. Take a look at our guide to learn more about different home improvement loans and how to pick the right one for your project.
• Construction Loan: If you’re starting your ADU project from scratch, a construction loan could be a great option. This loan gives you the money you need to cover the whole construction process, from buying materials to paying contractors. The good thing about a construction loan is it can make the whole financing process a lot simpler. Plus, it helps you manage the costs as you’re building your ADU.

Overall, you will find that RenoFi is the smartest way to finance your ADU project. ADUs not only increase your home’s value after renovation but can also generate rental income. However, ADUs are costly. If you don’t have enough equity in your current home, funding construction with a home equity loan is impossible.

 For example, let’s say your current home value is $500,000, and your outstanding mortgage balance is $400,000. You are planning on adding an ADU and expect the value of your home to increase to $640,000. Your current loan-to-value ratio (LTV) is already at 80%, which means that most home equity loans are out of reach because that’s the maximum LTV they allow. So, your borrowing power using your current equity is $0.

RenoFi, on the other hand, would allow you to go as high as 150% LTV of your current value or 90% of your after renovation value, whichever is lower. So, in this example, while using a standard home equity loan results in your borrowing power being $0, a RenoFi loan allows you to borrow up to $176,000 by using the after renovation value of your home!

Get started with your RenoFi loan here

RenoFi Can Help With Your ADU Project

We’ve covered some of the most practical ADU design ideas that work well when building new units from scratch or upgrading existing ones. As you would have figured, while these designs are cost-effective, implementing them can be costly.

The good news is that we can help you get the funds you need to complete your new ADU project or fix up your existing secondary suite. Our lending partners offer some of the most competitive loan products in the market, so consider reaching out to us to discuss your needs and connect with the right resources.

RenoFi loans are the smartest way to finance a home renovation project. Traditional loans are typically based on your current home value or require you to refinance your primary mortgage and give up your low rate. On the flip side, RenoFi loans are based on the after renovation value of your home. This allows you to borrow, on average, 11x more, get a low monthly payment, and keep your low rate on your first mortgage. Contact us today if you need help financing your ADU construction or renovation.