ADU's & DADU's - Candid Home Design

ADU’s & DADU’s

ADU & Multi-Generational Living Design — More Family, More Home, More Life

Family looks different than it used to. The homes we live in should keep up.

Grandma is moving in — and she deserves her own space, her own entrance, and her own independence. Your adult kid is moving back and you love them, but shared walls and one kitchen wasn’t the plan. You want the rental income from your property without selling it. You want your parents close but not underfoot, your kids nearby but grown, your family together but not on top of each other.

These are the situations that ADUs and multi-generational living design solve. And they’re some of the most personally meaningful projects we take on.

At Candid Home Design, we’ve designed in-law suites, detached backyard cottages, garage conversions, basement apartments, and above-garage units across hundreds of projects. We understand the structural complexity of adding a second dwelling to an existing property. We understand the design nuance of creating genuine independence within a shared property. And we understand — from our own experience moving closer to family — exactly why this matters.

Families are complicated. Homes don’t have to make them more so.

What Is an ADU — and Why Are So Many Families Building Them?

An accessory dwelling unit — ADU — is a secondary housing unit on the same property as a primary residence. It can be attached to the main house, built above a garage, converted from an existing structure like a basement or garage, or built as an entirely separate structure on the property. It has its own living space, kitchen, and bathroom. It functions as a complete, independent home — just at a smaller scale and on shared land.

The reasons families build them are as varied as the families themselves. Aging parents who want to be close to their children without giving up their independence. Adult kids who need a landing pad while they get established. Families who want a caregiver nearby without giving up privacy. Homeowners who want to generate rental income from their property while keeping the option of family use down the road.

What all of these situations share is a need for real design — not just a room added to the house, but a complete living environment that gives its occupant dignity, privacy, and a home that actually functions as one.

ADU Types We Design

Attached In-Law Suites

An attached in-law suite is built as part of the main house — sharing at least one wall — but functions as a fully independent living space with its own entrance, kitchen, bathroom, and sleeping area. Done well, it provides genuine separation: a family member who is close without being in the middle of everything, present without sacrificing privacy on either side.

These projects involve real structural work — modifying the existing home’s layout to carve out or add space for the suite, creating a separate entry that doesn’t require passing through the main living areas, and ensuring the suite has everything it needs to function independently. We design attached suites that feel like intentional parts of the home rather than converted spare bedrooms with a kitchenette shoehorned in.

Detached ADUs and Backyard Cottages

A detached ADU is a completely separate structure on the same property as the primary home — its own building, its own foundation, its own roofline, connected to the property’s utilities but otherwise fully independent. These are the most flexible ADU type: entirely private, architecturally distinct if desired, and usable for family or rental without any shared walls or entries.

Detached ADUs are also among the more complex residential projects we design. A new building on an existing residential property involves zoning compliance, setback requirements, utility connections, and structural design from the foundation up. We navigate all of that as part of the design process and produce permit-ready construction documents your builder can work from with confidence.

DADUs — Detached Accessory Dwelling Units

In some jurisdictions, DADUs are defined and regulated separately from ADUs — typically referring to smaller detached structures with specific size and use requirements. Where DADUs are permitted, they can be an efficient and relatively affordable way to add a second dwelling unit to a property without the footprint or cost of a full detached ADU.

We stay current on ADU and DADU regulations across our service areas and design to the specific rules of your jurisdiction — because what’s permitted in one county may not be permitted in the next, and getting the zoning right before design begins saves significant time and cost.

Garage Conversions

An existing garage is often the most efficient path to an ADU — the structure already exists, the foundation is there, and the conversion work focuses on making the space genuinely livable rather than building from scratch. A well-designed garage conversion adds a complete dwelling unit to your property with less site disruption and often less cost than new construction.

The design challenges are real: garage floor slabs typically sit at a different elevation than the surrounding grade, ceiling heights may be tight, and insulation, mechanical, and window placement all need to be carefully considered to create a space that feels like a home rather than a finished garage. We design garage conversions that solve those challenges — producing a finished space that reads as a genuine dwelling, not a storage room with a bed in it.

Basement ADUs

A basement ADU converts an existing lower level into a complete, independent dwelling unit — typically with its own exterior entry, full kitchen, bathroom, and sleeping area. These projects have significant overlap with the basement conversion work we do across our remodel practice, with the added layer of designing for genuine independent habitation: egress requirements for habitable space, ceiling height compliance, natural light solutions, and full kitchen and bathroom fit-out.

For homeowners in markets where basement ADUs are permitted, this is one of the highest-return investments available — adding a rentable or family-use unit to an existing home without expanding the footprint. We design basement ADUs that meet all habitable space requirements and function as real, comfortable homes.

Above-Garage Apartments

Building living space above an existing or new garage is one of the most efficient ways to add an ADU to a property without consuming yard space. Above-garage apartments are fully detached from the main house, privately accessed by their own stair, and can be designed with enough space and finish quality to serve as genuine long-term housing — for family, for a caregiver, or as a rental unit.

These projects require structural design that accounts for the garage below — ensuring the floor system is properly engineered for residential live loads, that the stair access is well-positioned, and that the unit above relates architecturally to both the garage and the main house. We design above-garage apartments that feel purposeful and permanent, not like an afterthought perched above a two-car bay.

The Design Detail That Makes ADUs Work — Independence With Connection (when you want it)

The most important design challenge in any ADU or multi-generational living project often isn’t structural. When you’re designing for a separate space that will be occupied by family, it’s relational.

The suite needs to feel independent — its own entry, its own kitchen, its own sense of home — without feeling isolated. The connection to the main house needs to be close enough for comfort and convenience without eliminating the privacy that makes the arrangement sustainable long-term. The main house needs to retain its own sense of completeness rather than feeling like something was carved out of it.

These are design challenges. They’re solved through careful attention to entry placement, sightlines, acoustic separation, outdoor space allocation, and the way the ADU relates to the main house architecturally and spatially. We think through all of it — because an ADU that works structurally but fails relationally isn’t really working at all.

ADUs in Middle Tennessee — What to Know

Nashville and the surrounding municipalities have historically been more restrictive on ADU development than many other metro areas, but that is changing. ADU overlay zones are expanding in Nashville proper, and many of the surrounding communities — including areas throughout our core service area — are actively updating their zoning codes to allow or expand ADU development.

The rules vary significantly by jurisdiction. What’s permitted in one county may not be permitted in the next city over. Setback requirements, size limits, owner-occupancy rules, and utility connection requirements all differ and all affect what kind of ADU is possible on a given property.

We research the specific zoning requirements for your property as part of every ADU project. Our broader service area — throughout the Southeast and beyond — includes many markets that are significantly more permissive, and we bring the same design expertise to those projects that we bring to Middle Tennessee. If you’re not sure whether an ADU is possible on your property, the consultation is exactly the right place to find out.

Why Families Choose Candid Home Design for ADU Projects

Deep experience across every ADU type — attached suites, detached cottages, garage conversions, basement units, and above-garage apartments
Accessible and aging-in-place design expertise built into every ADU we design — from wider doorways to zero-threshold entries to layouts that work for every stage of life
Permit-ready construction documents that reflect your jurisdiction’s specific ADU requirements
Structural design knowledge — we work closely with engineers when the scope requires it and understand the complexity of adding a second dwelling to an existing property
Personal understanding of multi-generational living — we moved across the country to be closer to family, and we bring that perspective to every project
Family-owned and operated, remote-ready — serving Greater Nashville and homeowners throughout the Southeast and beyond

Frequently Asked Questions

Is an ADU the same as an in-law suite?

An in-law suite is a type of ADU — specifically one that’s attached to the main house and designed for family use. ADU is the broader term that encompasses all secondary dwelling units on a property, whether attached or detached, new construction or conversion. All in-law suites are ADUs; not all ADUs are in-law suites.

Can I build an ADU in Nashville?

It depends on your specific property and zoning. Nashville has ADU overlay zones where secondary units are permitted, and those zones are expanding. Many surrounding municipalities have their own ADU rules that differ from Nashville’s. We research your specific parcel’s zoning as part of every project — the consultation is the right place to find out what’s possible for your property.

How much does it cost to design an ADU?

Design fees vary based on ADU type, size, and complexity. A garage conversion or basement ADU is typically less design-intensive than a new detached structure built from the foundation up. We’re transparent about fees from the first conversation and will give you a clear picture of design costs during your consultation.

Do I need a permit for an ADU or in-law suite?

Yes — in virtually all jurisdictions, any ADU that includes a kitchen, bathroom, and sleeping area requires a building permit. Permitted ADUs also protect your property value and ensure the unit can be legally occupied and, where applicable, legally rented. We produce permit-ready construction documents for every ADU project we design.

Can an ADU be designed for aging in place?

Absolutely — and we’d argue it should be, regardless of who’s moving in today. Wider doorways, zero-threshold entries, roll-in shower capability, and accessible layout planning add minimal cost at the design stage and significant value over the life of the unit. We bring formal accessible design training to every ADU we design.

Can you design an ADU if I'm outside of Nashville?

Yes. Our process is remote-first and we work with homeowners throughout the Southeast and beyond — including many markets that are significantly more permissive on ADU development than Middle Tennessee. If you have a property and a project, reach out and let’s talk.

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Serving Greater Nashville — Brentwood, Franklin, Gallatin, Lebanon, Murfreesboro, and surrounding Middle Tennessee — plus remote home addition design throughout the Southeast and beyond.