A Practical Guide to Designing Duplex Homes That Sell

One of the many benefits of duplex housing is its ability to appeal to multiple buyer profiles. As a kind of halfway point between single-family homes and high-density housing, duplexes offer the benefits of multifamily living with an experience that’s closer to a single-family home. When done well, duplexes add value compared to single-family homes and allow buyers to purchase a new home in highly desirable neighborhoods or master-planned communities. Using a recent KGA project as an example, let’s walk through some key benefits of this housing type and duplex design best practices.

Everyone Benefits from Duplex Housing

Duplex housing, often marketed as paired homes, offers many advantages:

• Helps achieve lower price per square foot goals
• Is less of a liability risk compared to higher-density housing types
• Provides an attractive multi-unit housing solution to states and cities that have restricted or eliminated single-family zoning (California, Oregon, Washington, and Maine, for example)
• Pricing is typically more attainable compared to single-family detached homes
• Has the flexibility of targeting move-up buyers, move-down buyers, or both at the same time, depending on its location and design
• Offers a lower-maintenance, lock-and-leave living experience, making it especially appealing to empty nesters wanting to live closer to family

Top-Selling Duplex Design Tips

Creating duplex housing is an architectural design tightrope. It must meet your cost per square foot requirements, which can be tough in today’s market. Plans should also appeal to more discerning buyers: downsizers, empty nesters, or those who prefer a similar single-family home living experience with lower maintenance.

Tip: Hire an architectural team experienced in designing this type of housing at scale so it’s financially feasible. “If it’s designed properly, a duplex can feel like a single-family home,” says KGA Partner and Director of Design John Guilliams.

KGA’s recent work for Brookfield Residential’s Villa Portfolio at Central Park is an example of good duplex design principles. Guilliams’ thoughtful approach to exterior and interior architecture made these paired home plans shine in this desirable Central Park location. He had initially designed the home plans for Brookfield at The Village at Castle Pines. Buyer interest and sales were so favorable the builder used them a second time at Central Park. Peek behind the design curtain for some duplex design tips in action.

Use Exterior Architecture to Distinguish Units

In a paired home, each home’s exterior should distinguish itself from the other, but not so much as to look like two separate units. “Use the same kits of parts for the whole building to avoid a disjointed look,” says Guilliams. Here’s how:

1. Use materials carefully

Keep siding, roofing, trim, windows, and doors uniform throughout the structure. Create distinction through articulation. Maintain a consistent color palette throughout the attached units and each building.

2. Separate unit entry

If the site allows, give each homeowner a more private entry experience. First designed for the Village at Castle Pines, Guilliams took advantage of the site’s corner lots to separate the front doors of each unit. It may seem like a small detail, but it adds distinction and offers a private “coming home” feel that mimics the sense of arrival of a single-family detached home.

3. Mind the garage

Garage placement makes a big visual impact. In general, avoid side-by-side garages to prevent awkward massing in the front elevation. Alley-loaded garages for Brookfield’s Villa Portfolio further distinguish each home for a more single-family home look. If alley-loading isn’t feasible, consider creating a zig-zagged shared wall to offset the garages (these paired patio homes are an example).

Make the Interior Feel Like a Single-Family Home

The single-family feel extends to the interior, too. Here are several must-have interior features to set your project apart:

• Create a distinct entryway with enough space for a coat closet or small drop zone and room to greet guests.
• Ceiling height on the main level should be a minimum of 9 feet.
• Pay close attention to circulation on the main level and shared living spaces.
• Offer an optional finished basement for additional square footage.
• Include a primary suite on the main level if you’re targeting empty nesters. “Villa Portfolio was popular with grandparents buying to be closer to their kids and grandkids,” says Brookfield Residential Sales Representative Bill Gleeson.

Create an Open Floor Plan

Interiors should mimic traditional single-family detached plans by minimizing visual clutter and obstructions. “Buyers consistently said that when they were inside the homes, they didn’t have any sense of them being paired at all,” says Gleeson.

Paired home designs should focus on open-concept plans to keep sightlines clear. Because each room flows easily into the next, natural light can move through the space to make the main level appear larger.

Emphasize the Kitchen

Kitchens still sell homes. In a duplex, create kitchens as the main-level destination so they’re on par with what buyers can find in a single-family detached home.

Size, location, and fixture quality matter. Eliminate visual obstructions to keep the area open, airy, and connected to other parts of the main level. Similar to the Villa Portfolio homes, place the kitchen adjacent to an exterior wall so that incoming natural light makes the space appear larger. “Buyers loved the bump-out kitchen’s size and it was a selling point,” says Gleeson.

When it comes to layout and fixtures, avoid the condo kitchen. Appoint the kitchen with a large center island or peninsula with space for barstools, lots of cabinets, and plenty of countertop space. If there’s space for a walk-in pantry or appliance garage, include them.

Pay Attention to the Shared Wall

The shared wall is a common buyer concern in any multifamily dwelling. Make sure you get the highest STC rating possible, a minimum 55 STC rating is Guilliams’s recommendation. Overcome potential objections to a shared wall with thoughtful attention to room placement. Some examples include:

• Avoid back-to-back bedrooms along the shared wall, especially the primary suite. Villa Portfolio includes a primary on the main level that offers privacy and caters to empty nesters.
• Stagger or buffer each plan’s living room to reduce TV noise transmission. For example, the Villa Portfolio duplex has one plan’s living room and the other’s powder room along the common wall. 
• Use the shared wall for infrequently occupied spaces: stairwells, laundry rooms, closets, and bathrooms.

Maximize Windows

Each duplex unit loses an exterior wall, so make up for the loss of natural light on that side with plenty of windows on the remaining sides. “The width of each unit should be no more than 35 feet to allow natural light to reach the interior shared wall,” says Guilliams. The garage may occupy most of the fourth wall, so plan for plenty of windows on the other two.

Given these constraints, use windows effectively to bring in light and create character. If privacy is an issue, consider clerestory or transom windows to bring in natural light above eye level.

Include Outdoor Living Spaces

Unlike a multifamily building, a covered porch isn’t enough in a duplex. (No one wants to see grills from the street, after all.) A fenced-in side yard or courtyard for outdoor living is a must. It’s also more pet-friendly for households with furry family members.

An outdoor space doesn’t have to be large, as lower-maintenance living is part of this housing type’s appeal. It should also be private and have enough space for a small patio, dining set, and grill. Indoor-outdoor transitions are opportunities to visually expand living spaces — a multi-sliding door can resemble a glass wall and brighten up the interior.

Duplex Design Takeaways

As more states and cities reform zoning restrictions or eliminate single-family restrictions altogether, duplex housing deserves more attention. Designing duplexes or paired homes that sell can pose challenges because of the variety of buyer profiles targeted, buyer expectations, and price point requirements. For best results, partner with an architect with duplex design experience to create appealing home plans that live well and align with your business objectives. To see more of KGA’s duplex designs, visit our portfolio of attached and multifamily projects.