ADU Guide

Choosing ADU Floor Plans

There are many design options for choosing your custom ADU floor plans & layout. Check out our guide to determine what makes the most sense for your ADU.

Caleb LeeMay 28, 2021

Accessory Dwelling Units come in many different shapes and sizes, from an attached garage conversion or an in-law suite to a backyard guest house or a basement studio apartment. Determining the right ADU for you and your property's needs can leave you wondering where to start.

Do you want a wrap-around porch or a walk-in closet? Do you want shared backyard access on the ground floor? It can be overwhelming to start making these choices, especially without the support of an architect, general contractor, or plan designer to walk you through the possibilities.

In this article, we walk through the different use granny flat cases and interior floor plans that we have designed for homeowners like you and provide the reasoning behind each design and layout decision.

At Cottage, we believe in designing your custom, stick-built ADU in a cost-effective and smart way to give you the best bang for your buck while matching your needs, budget, and use case(s) for your ADU unit. Already thought through the ADU floor plan that's right for you? Click the "Get Started" button on the top right hand corner to get a Free Consultation and Estimate Today.

ADU for the Family (& Friends too!)

As the COVID-19 pandemic has shown, keeping family members close can be an important consideration for your multi-generational family. Maintaining comfort and flexibility are important must-haves for many homeowners - Cottage has designed many ADUs with this in mind.

This custom craftsman, 748 sq ft ADU is the classic example of this ADU use case for a couple in Los Altos. While considering options for their daughter moving back into the Bay Area, they quickly realized that they could finance and build a beautiful 1 bedroom ADU for the monthly cost of her San Jose apartment.

Cottage's in-house design team drew up a floor plan that met the family's needs: a full master bedroom opening to a shared outdoor living space facing a glorious Live Oak tree, with an open floor plan kitchen, dining, and living room area, including a custom desk and additional millwork to complete the space:

ADU Floor Plan - Daughter Move-in

Other homeowners have made similar realizations that the existing space or structures in their backyards can be converted into fully ADU living spaces. For one Palo Alto family, a historic garage could be transformed from an underloved storage area into a great space for family and entertaining guests.

The site plan added to the existing garage space to create a bright, spacious living room, dining area, and kitchen area with two sets of double swing French doors opening up to the backyard space for a seamless indoor-outdoor transition.

ADU Floor Plan - Palo Alto Garage

Cottage's custom design and stick-built approach to the ADU design and build process means that we are able to work with homeowner budgets and needs while unlocking value engineering opportunities with our ADU-specific knowledge and expertise. This applies to your ADU, whether it's for family and friends or for a different use case such as those below.

Retirement or Age-In-Place ADU

Many homeowners we have spoken with have voiced that they see ADUs as a potential alternative to nursing or retirement home living. We couldn't agree more—why buy a new property for your loved one and move out of your primary residence when you can build an ADU for independent living in your backyard? Family and neighborhood roots are important to us and to many homeowners like you, and backyard Cottages have long presented a unique opportunity to provide space and proximity for elderly parents and grandparents.

One example of this was the large 1,196 sq. ft retirement ADU we designed for a longtime Los Altos resident. With the kids long gone and uses for the full 5-bedroom, 4,000 sq. ft-plus existing home decreasing with each passing year, she saw her ADU as a chance to downsize her living space without downsizing her expectations. More importantly, the detached ADU unit allowed her to remain in her hometown and her beloved property while opening up the option of renting out the larger main house.

Retirement ADU Floor Plan Interior Axon

Her floor plan was the retiree's dream: a mid-century modern complex with a hosting area and living quarters divided by a long hallway and courtyard space, with vaulted ceilings and open floor plan to accentuate the luxurious space. For this retiree, comfort and customization were the top priorities for her ADU.

Retirement ADU Floor Plan

Other homeowners have taken the longer term view for their ADU—while they may not need the space for parents now, they want to be prudent in planning for a future where the family can stay close together while still maintaining privacy and independence.

This charming 1 bedroom, 350 sq. ft in-law unit in Redwood City was one that fit this description: a multi-generational living space customized to match the main home and built around a shared courtyard with the existing buildings.

Multi-Generational ADU Unit Floor Plan Interior

Double French doors open from the open living and kitchen area into the courtyard, while a bedroom and full bathroom comes with an additional, unique feature: a fully custom sauna for the whole family to use.

Multi-Generational ADU Unit Floor Plan

Mixed-use ADU

Some homeowners appreciate the many utilities that ADUs bring to the table. Whether that's rental income for now and retirement later, friends and family now and personal use later, or some other combination of usages, a custom ADU can be the answer to multiple scenarios simultaneously.

Take this Castro Valley couple as an example: with a large backyard, the possibilities were nearly endless for the homeowner. They wanted an easy process and efficient use of space that was comfortable enough for them to live in someday but cost-effective enough to work from the start as a rental unit. The result was a Cottage-designed 750 sq. ft, 2 bedroom, 1 bathroom ADU that combined efficient space planning with a touch of luxury to meet both the shorter-term and longer-term ADU needs.

Mixed-Use ADU Floor Plan

Cottage works with homeowners like this Castro Valley couple to meet your specific ADU needs with a custom, stick-built ADU tailored to you. There are many use cases for ADUs as the above examples have shown, and Cottage is here to walk you through the best Accessory Dwelling Unit for you.

Rental Income ADU

Property investors across the Bay Area have begun to see the lucrative potential of ADU construction across the region. With high rental potential in many municipalities and the prospect of a start-to-finish ADU construction process, Cottage has worked with property investors to help add to California's housing stock as well as their investment portfolios.

With many of these investors looking to build multiple ADUs on one property, Cottage has a breadth of experience in value engineering and driving cost savings with the priority of maximizing return-on-investment. For example, Berkeley property investor Harmol came to Cottage looking for a fast yet custom, efficient yet effective solution for his ADU plans. Cottage drew up a duplex ADU floor plan that was the best of all worlds: two 578 sq. ft ADU units with a shared wall to bring down costs.

Rental Income ADU Berkeley

By splitting the design down the middle of the structure, the Cottage design team was able to significantly reduce the total construction costs while minimizing other costly site preparation and trenching needs for the duplex units.

What is Next for My ADU?

In this article, we've reviewed a few of the most common use cases for ADUs that we hear about from homeowners like you every day.

Whether you're building an attic apartment or a junior ADU (JADU), we hope you found some inspiration in this article for how to make the best ADU layout decision for you and your family and property's needs. From large windows for natural light or open-plan dining to a loft bedroom, a home office, or a shared deck, the possibilities for your ADU design are endless. Now, it's time to assemble those building permits and get to work.

ADUs are a great way to expand your primary dwelling, create additional properties for rent, or increase housing affordability and availability in your neighborhood. The architectural designs are only one step on your ADU checklist, and you may benefit from a helping hand as you bring your plans to life.

The construction of ADUs can be fun, but there are also many safety code requirements, plumbing installations, fees, and state laws to consider before application submittal. The professionals at Cottage can help you every step of the way, from architecture to preparation of your Building Permit submittal and everything in between.

Have you thought through your custom ADU floor plan already or want to speak with us about your ADU needs? Click the "Get Started" button below to get a Free Consultation and Estimate Today!

Get your free consultation and estimate today!