Homeowner TA: Outreach Content – Designing Your ADU

Hiring a Designer or Architect

Although you can build an ADU as an owner-builder, we strongly recommend hiring a licensed architect or designer and a licensed contractor, or a design/build team, and most homeowners do. Bringing on a professional early in the process is often key to getting your ADU approved quickly, managed efficiently, and built cost-effectively. Relevant experience and fit are critical, and it’s important to look at their past work and check references.

Based on the type of ADU and your project details, your team may include:

• Licensed architect or designer to design your ADU and potentially see you through permitting and construction
• Engineers and specialty consultants (examples: septic consultant, landscape architect)
• Licensed contractor to build your ADU
• Design/build company that designs and builds your ADU
• Modular/prefab company who sells preset designs for modular/prefab homes

Design Questions to Consider

Here are some notes and questions to get you started on the design process. Remember, all of these might change when you start discussing costs.

1. What type of ADU do you want? Detached, attached, internal, etc.
2. Are you interested in a site-built custom design or a factory-built/prefabricated unit? What are the pros and cons of each?
3. If you belong to a Homeowners Association, do they have guidelines you’ll need to follow?
4. Do you want a modern or traditional feel?
5. What are some houses that you like and why?
6. Are there floor plans you like/don’t like? What features stand out?
7. Are there features in your current home or past homes that you loved or felt could be improved that can help inspire your ADU?
8. How many bedrooms do you want? How many bathrooms do you want, and do you want them larger or smaller?
9. Do you want more communal space (living room) or larger bedrooms?
10. What kind of kitchen do you want (chef’s kitchen or something less expensive)?
11. Will there be a washer and dryer in the unit?
12. Do you want features that will help people stay in the home as they age or that account for special needs? e.g., level entry, accessible bathrooms, grab bars, no stairs, etc.
13. Are there weather and/or sustainability concerns to take into consideration? Think about energy use and generation, water use, fire resistance, heating and cooling, and related topics.
14. Are there landscaping plans you would like to incorporate?
15. Do you have preferences about the flow of the house? Such as: entrance should be here, a door to the garden, etc.
16. How should you situate your ADU on your property? Think about natural light, access to utilities, and privacy (for both the primary residence and the neighbors).
17. Do you want to create outdoor space adjacent to the ADU? Are there trees or features to protect?

Design Features for ADUs

Plan for the Future: Think about how you will use your ADU now and in the future. Let your design team know what you’re thinking and they may suggest features you might want to include.

Small-Scale Living

• Beds that do double duty – Murphy/fold-down beds and convertible sleeping spaces (futons, day beds) provide flexible use of space and furniture.
• Storage can be maximized with drawers or cabinets under built-in benches, double-sided kitchen islands, and full-height shelves or cabinets.
• Movable furniture (on casters/wheels) makes for easy reconfiguration and flexible use of space.
• Pocket doors reduce the clearance space needed for a door and can be kept open to improve flow in the space.
• Well-designed outdoor spaces can increase your living area when the weather is nice.
• Windows have a big impact on how the space feels. Corner windows make rooms feel larger. Skylights and windows above eye level provide daylight, privacy, and extra wall space for storage.
• Ceilings Higher is not always better! Talk to your designer about the right balance.

Privacy & Security

• Separate outdoor living spaces can be created with strategic placement of the ADU and landscape features.
• Thoughtful placement of windows can reduce unwanted lines of sight in and out of the unit, particularly in relation to neighboring properties.
• Careful selection of window coverings (example: shades that can open from the bottom or top) can increase functionality while maintaining privacy.
• Sound- and odor-proofing may be a good investment when sharing your property, especially for attached or internal ADUs.
• Smart locks can help keep the ADU secure and help your ADU occupant feel safer.

Amenities

• In-unit laundry is a top amenity for renters that is often overlooked. Consider stacking units in a closet and placing them in the kitchen or bathroom to keep plumbing fixtures close to each other.
• A dishwasher may reduce storage space but free up counter space and is extremely useful for small families or households with more than one occupant.
• Air filtration helps protect the ADUs occupants from poor air quality and pollutants, which can be especially important during shelter-in-place and wildfire events. Air filtration can be installed as a standalone system, connected to duct work, or integrated into HVAC equipment.

Green Features

• Orientation of the unit in relation to trees, the main home, and other structures will affect sun exposure and shading, both of which impact heating and cooling and solar power generation.
• Energy- and water-efficient fixtures reduce utility costs and help conserve resources.
• Smart thermostats can lower utility costs and improve energy efficiency.
• All electric energy and appliances reduce both the environmental impact of your ADU and the cost of infrastructure connections.
• Well-placed outlets reduce the need for extension cords and power strips that require more energy and can trip circuits.

Universal Design and Accessibility

• Accessible entries have no steps and low or no threshold for easier wheelchair/walker access.
• Low-mobility bathrooms may feature curbless showers (which can also make a bathroom feel larger!), shower seats, towel racks that double as grab bars, floating vanities, and automatic nightlights.
• Design for high visibility uses natural light, which is easier for aging eyes to see, high-contrast floors and counters to improve visibility, and automatic lights in outdoor spaces.
• Nonslip flooring for indoor and outdoor spaces reduces the risk of a fall for people of all ages.

Cost Considerations

• Utilities: The further your ADU is from utility hookups, the more it may cost to get them connected. Talk to your designer about your options.
• Kitchens and bathrooms are typically some of the most expensive parts of the ADU, but the smaller they are the more you can customize with higher cost materials and fixtures without blowing your whole budget.
• “Wet walls” save money by putting plumbing for bathrooms, the kitchen, laundry, and other similar uses together in the same wall or part of the ADU.
• Durable finishes will require less maintenance over time and help attract long-term tenants.