The way American families live under one roof is changing, and home builders are adapting faster than ever. According to the American Institute of Architects, demand for multigenerational housing jumped from 41 percent of survey respondents in 2019 to 54 percent in 2020, a shift driven by economic pressures, health considerations, and changing family priorities. This surge has profound implications for how builders design, specify materials, and plan communities. For builders exploring how to accommodate multiple generations under one roof, our guide to building homes for every generation offers practical strategies for flexible floor plans. Below, we examine the key design shifts, exterior trends, material choices, and market conditions that define this new era in residential construction.
The Rise of Flexible Floor Plans for Multigenerational Living
The most immediate change in home design is the move toward layouts that accommodate multiple generations without sacrificing privacy. Builders who once focused on open-concept great rooms are now adding separate suites, dual-primary bedrooms, and compartmentalized living zones.
Accessory Dwelling Units as a Design Feature
Rather than treating an accessory dwelling unit as an afterthought, leading builders are integrating them into the primary structure. These spaces typically include:
- A private entrance separate from the main home entry
- A compact kitchenette or full kitchen with reduced appliance footprints
- A bedroom and full bathroom on the ground floor
- Separate HVAC zoning for independent temperature control
- Sound-dampened walls between the ADU and the main living area
These units serve aging parents, adult children returning home, or even rental income when not occupied by family. The flexibility of the design makes the home more marketable across buyer demographics.
Single-Story Living Gains Traction
The AIA survey recorded an 11 percent increase in demand for single-story homes in 2020. This trend aligns directly with multigenerational needs, because older family members avoid stairs and younger children stay closer to supervision. Builders are responding by designing wider footprints rather than taller structures, which requires larger lots and smarter site planning.
Dual Primary Bedroom Suites
One of the fastest-growing requests among buyers planning for multigenerational use is the dual-primary-bedroom layout. Instead of one oversized master suite and smaller secondary bedrooms, the floor plan includes two similarly sized suites on opposite ends of the home. Each suite features:
- A bedroom large enough for a king bed and sitting area
- A walk-in closet with accessible shelving at multiple heights
- An ensuite bathroom with curbless shower and grab-bar blocking
- Direct access to a shared outdoor space such as a patio or porch
This layout gives two generations equal comfort and privacy while keeping them under the same roof. For builders working with active adult buyers, understanding how two generations of buyers need different homes is essential for meeting these distinct requirements.
Exterior Design Trends That Support Multigenerational Living
Homeowners investing in multigenerational homes want exteriors that require minimal upkeep and remain functional as family members age. The AIA study found that low-maintenance and durable exterior products topped homeowner wish lists.
Front and Side Porches Gain Momentum
Porches saw an 8 percent increase in popularity in 2020, the largest gain of any exterior feature measured. For multigenerational households, porches serve as shared outdoor space where family members of all ages can gather without leaving the property. Builders are specifying:
- Covered front porches at least 8 feet deep to accommodate seating
- Side porches with screened enclosures for bug-free evening use
- Accessible ramp integration that matches the porch aesthetic
- Low-maintenance decking materials that resist splintering and fading
Low-Maintenance Siding and Trim
The survey showed that only 19 percent of respondents saw a trend toward simpler exteriors, down from 23 percent in 2019. Instead, homeowners want durable, high-performance cladding that does not require frequent painting or repair. Options gaining specification include engineered wood siding, fiber cement panels, and vinyl with integrated insulation. These materials reduce the maintenance burden across generations and improve the home’s long-term durability.
Fire-Resistant Materials Become a Priority
Fire-resistant exterior products saw a 3 percent year-over-year gain, reflecting growing awareness of wildfire risk in expanding development areas. For multigenerational homes, where older and younger family members may have limited mobility during an evacuation, fire-resistant construction provides a critical safety buffer. Builders are specifying Class A fire-rated roofing, non-combustible siding materials in high-risk zones, and tempered windows in accessible egress paths.
Window and Fenestration Trends for Modern Homes
Windows emerged as the exterior category with the most significant change in 2020. The AIA study reported that 47 percent of respondents identified window count and size as a priority for homeowners, and the push toward larger, more energy-efficient openings continues to reshape exterior designs.
Larger Windows for Natural Light and Views
Brenda Brunk, product portfolio strategist for Marvin Windows, noted that the desire for bigger windows is not slowing down. Homeowners want expansive glass that floods interiors with natural light, a feature that benefits multigenerational households by making shared spaces feel larger and more connected to outdoor areas. Key specifications include:
| Window Feature | Benefit for Multigenerational Living | Specification Priority |
|---|---|---|
| Low-E insulating glass | Reduces heat gain and UV damage in shared spaces | High |
| Triple-pane glazing | Improves thermal comfort and sound insulation between rooms | Medium-High |
| Energy Star certification | Lowers utility costs across all household members | Required |
| Casement and awning operation | Easier to open for older adults than double-hung styles | Medium |
| Impact-rated glass | Safety in storm-prone regions for vulnerable family members | Regional |
For builders selecting fenestration products that balance performance and aesthetics, a review of professional window products for builders provides specification guidance across material types.
Energy Performance as a Family Budget Decision
The National Association of Home Builders identified Energy Star windows as the top green feature requested by first-time homebuyers, and the same preference holds for multigenerational buyers. Triple-pane and low-E coatings reduce heating and cooling loads, directly lowering monthly expenses. In a multigenerational home where utility costs are shared among income earners, energy-efficient windows deliver a measurable return that appeals to every generation living in the house.
Operable Windows for Accessibility
Window hardware matters more in multigenerational homes. Casement windows operated by a single crank handle are significantly easier for older adults and children to open than traditional double-hung sashes. Builders should specify windows with low operating force requirements and hardware placed at reachable heights, particularly in bedrooms and common areas designated for aging family members.
Market Conditions Favoring Multigenerational Housing
The AIA recorded record highs for inquiries, billings, and design contracts during the third quarter of 2020, with all three measurements exceeding the prior five-year benchmarks. Architecture firms saw a 5.6 percent average increase in backlogs from the second to third quarter, signaling sustained demand for residential design services.
Remodeling and Addition Activity Surges
Remodeling work for additions and alterations grew 22 percent year-over-year, the largest gain of any sector tracked. Kitchen and bath remodels followed with a 21 percent increase. These numbers indicate that existing homeowners are adapting their current homes for multigenerational use rather than moving, a trend that creates opportunities for builders who offer addition and conversion services.
New Construction Opportunities in Custom and Luxury Homes
Move-up homes, second homes, custom luxury residences, and vacation properties all saw major jumps in demand. For builders, this means that new construction projects increasingly include multigenerational requirements from the initial design phase rather than as retrofits. Key market indicators:
- Custom home design contracts exceeded five-year averages in all U.S. regions
- The West led the nation in inquiry and billing growth, with the Midwest trailing
- Single-story luxury homes with separate family suites commanded premium pricing
- Townhome and condo sectors underperformed, suggesting buyers prefer detached homes for multigenerational arrangements
Designing for Long-Term Occupancy
Multigenerational buyers are planning for 10 to 20 years in the same home, which changes how builders approach material durability and system selection. Products must withstand heavier use from more occupants, and mechanical systems must handle higher loads. Builders who want to capture this growing segment should study how to design attainable homes that buyers actually want, balancing upfront cost with long-term livability.
Planning Implications for Builders
Builders entering the multigenerational market should adopt a deliberate approach to product selection and site planning. The following strategies help capture this demand:
- Include at least one ground-floor bedroom with full bath in all new plans
- Pre-wire for separate HVAC zones to give each generation temperature control
- Specify wider doorways (36-inch minimum) and zero-threshold entries as standard
- Design kitchens with varied counter heights to accommodate wheelchair access and children
- Offer optional ADU packages that integrate with standard plan sets
- Select siding, roofing, and window products with 20-year-plus service lives
- Partner with local trades who understand aging-in-place and accessibility construction
- Market multigenerational features explicitly in sales materials and model homes
Conclusion
The shift toward multigenerational housing is not a temporary reaction to economic conditions but a structural change in how American families choose to live. With AIA data showing double-digit growth in demand, record design-contract backlogs, and strong preferences for single-story, low-maintenance, energy-efficient homes, builders who adapt their floor plans, exterior specifications, and market positioning will capture a growing share of buyers. The builders who treat multigenerational design as a core competency rather than a niche offering will be best positioned as the demographic trends driving this shift continue to strengthen.