For a growing number of families, the ideal home is no longer designed for only one generation. Parents are planning for aging relatives. Adult children are returning home after college. Grandparents are helping with childcare. Other families simply want to live closer while sharing expenses, responsibilities and everyday life.

Although the percentage fluctuates from year to year, multigenerational home buying remains a significant part of the housing market. According to the National Association of Realtors, in 2026 so far, 14% of home buyers purchased a multigenerational home. The most common motivations included caring for aging parents, saving money and creating space for adult children moving back home.

Three Ways to Design a Multigenerational Home

The phrase “multigenerational home” often suggests one large house shared by everyone. That is only one possibility. Deltec homes can be designed with varying levels of separation and independence.

1) Create Private Living Areas Within One Home

The simplest option may be to create distinct zones within the main home. A multigenerational floor plan could include:

• Bedrooms located in separate sections of the home
• More than one primary suite
• A private bathroom for each generation
• A secondary sitting or family room
• A kitchenette or coffee bar
• Separate outdoor entrances
• Additional storage
• Sound separation between living areas

Because Deltec’s round homes do not require interior load-bearing walls, the interior floor plan can be configured around the needs of the people who will live there. This flexibility makes it possible to balance open gathering spaces with private bedrooms, bathrooms and retreats.

This arrangement works especially well for families that want to share a kitchen and central living space while still giving each generation a place to retreat.

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Our 2000 model with a 16′ x 18 connect to a 500 model with a separate living room, bedroom and kitchenette

2) Connect Two Distinct Living Spaces

Families seeking greater separation can create connected living areas within one overall home design.

For example, a primary Deltec home could be connected to another round structure or wing containing a bedroom, bathroom, living room and kitchenette. The connecting area can provide convenient access between the residences while preserving a greater sense of privacy.

A connected multigenerational design may be appropriate when:

• An older parent wants independence but should not live completely alone
• Two households want separate daily routines
• Family members want private kitchens or living rooms
• Accessibility or caregiving needs may increase over time
• The family wants the property to feel cohesive rather than adding a completely separate building

Depending on the design, a connecting space might function as a hallway, mudroom, shared entrance, laundry area or transitional gathering space.

A 1000 model with 16′ x 16′ connect to a 1000 model

3) Add a Backyard Cottage or Mother-In-Law Suite

A detached backyard cottage offers another approach: living together on the same property without living under the same roof.

Accessory dwelling units and backyard cottages are increasingly being considered by families that want to remain close while maintaining privacy and independence. They can also make caregiving easier and help older adults remain in a familiar community.

Deltec’s new Backyard Cottages bring the company’s round design to a compact footprint that can complement an existing home and landscape. 

A 2000 model on a finished basement

Refuge

At 326 square feet, the Refuge is a compact studio cottage with one bathroom and six floor plan options. It can be configured as a guest suite or as a flexible space that transitions between a home office and sleeping area.

For a relative who regularly spends time with the family in the main home, the Refuge can provide a comfortable private bedroom, bathroom and sitting space without creating more square footage than necessary.

Sanctuary

At 517 square feet, the Sanctuary provides additional room for living, sleeping and storage while retaining an open studio layout. It also offers six floor plan options and one bathroom.

Its larger footprint may make the Sanctuary particularly appealing as a mother-in-law suite, guest cottage or private retreat for an adult family member.

Both models use an open design with only one primary interior wall enclosing the bathroom. Vaulted ceilings, circular geometry and windows positioned around the structure help the interiors feel larger and brighter than their compact footprints might suggest.

When a Complete ADU Is Needed

Some families need more than a guest suite. A relative who will live independently may require a full kitchen, dedicated laundry, additional storage and a more traditional one-bedroom floor plan.

Deltec’s 517-square-foot Nest offers studio or one-bedroom configurations and can provide a more complete auxiliary dwelling. Deltec distinguishes the Nest from the simpler Backyard Cottage models by offering plans that can include a full kitchen and washer-and-dryer space, along with more comprehensive construction documentation and support.

Before choosing a model, consider whether the space will be used primarily for sleeping and relaxing or whether it must function as a fully independent residence.

Designing a Mother-in-Law Suite for Aging in Place

When a backyard cottage or private suite will accommodate an older relative, it is helpful to plan for future mobility and caregiving needs—even when those features are not immediately necessary.

Consider incorporating:

• A step-free entrance
• A curbless or low-threshold shower
• Wider doorways
• Lever-style door handles
• Easy-to-reach storage
• Slip-resistant flooring
• Good interior and exterior lighting
• Space to maneuver around furniture
• A bathroom that can accommodate future grab bars
• A direct, well-lit path to the main house
• Space for a caregiver or overnight guest

Planning these details during the design process is generally easier than modifying the home later.

Questions to Ask

Before selecting a floor plan, talk openly about how the household will function.

Determine whether family members will share meals, entrances, laundry facilities and outdoor areas—or whether each household needs its own.

A returning adult child may eventually move out. An older parent may require more support. A space designed for one purpose should ideally be able to serve another later.

A guest cottage used by someone who eats most meals in the main home may only need limited food-preparation space. A completely independent residence will likely require a code-compliant kitchen and additional utility connections.

Think beyond current needs. Wider pathways, fewer thresholds and an accessible bathroom can help the space remain comfortable for decades.

Zoning, setbacks, minimum lot sizes, utility requirements, parking rules and ADU definitions vary by location. A detached structure marketed as a guest cottage or mother-in-law suite may not automatically qualify as a legal independent dwelling. Homeowners should consult their local planning department, building officials and applicable homeowners association before finalizing the design.