Nestled in the lush landscape, a modern reinterpretation of a once-fallen barn now features a charming guest cottage with stylish details and contemporary amenities. Situated along a narrow lot in Germantown, New York, the cottage completes a cluster of existing buildings, forming an intimate courtyard on one side. Steel effect folding patio doors fully open the living areas to the expansive fields and the Catskill Mountains beyond. The homeowners, a young family with parents living abroad, envisioned a cozy yet modern ADU for extended stays. Designed by Lauren Cawse, AIA, architect and partner at The Art of Building, the year-round retreat draws inspiration from traditional local barns while embracing a seamless indoor-outdoor connection. Captivating Guest Cottage Design Enhances the Senses with Steel Effect Folding Patio Doors The modern ADU design started with the site itself. Positioned between residential and commercial neighbors, the elongated property required a careful balance of privacy and openness. Architect Lauren Cawse approached the layout by redefining the existing house and garage as the east and west sides of an outdoor room, with the new cottage forming its southern boundary. This arrangement created a clear courtyard near the main residence while directing the 800-square-foot guest house toward the open meadow and the distant Catskill Mountains. “The unique character of the site and its history inspired the architectural direction,” says Cawse. “The intent was to create a secondary structure in the compound in clear contrast to the modern farmhouse style of the house and garage.” A Barn-Inspired Exterior Adds Visual Flair The exterior envelope evokes a traditional barn with a simple gable shape, weathered wood siding, cedar shingles, and a foundation veneer made of local fieldstone. A large sliding barn door adds a complementary feature to the courtyard-facing side, creating a dynamic opening that maintains uninterrupted views through the cottage to the meadow beyond. Steel effect folding patio doors surrounding the structure add a modern touch of transparency, and simulated divided lites allow the contemporary glass wall systems to harmonize with the traditional elements of the modern ADU design. “The goal was to fully open the living areas to the outdoors, framing views to the meadows and mountains,” says Cawse. “The positioning of the NanaWall systems frames the views and, when open, dissolves the boundary between inside and out.” Interior Design That Mirrors Nature’s Tranquility Inside, the design program features a simple layout with one bedroom, a full bath, a kitchenette, and a living area with a wood-burning stove. The interior, a collaboration between The Art of Building and the homeowners, is defined by an understated palette and tactile materials that reflect the natural setting. Color is introduced through the framed glass views on all sides of the structure. Reclaimed timber collar ties span the ceiling overhead, while stone surfaces and naturally patinated metal accents add quiet texture throughout. Custom hand-painted Delft tiles along the kitchen backsplash add personal detail, and terra cotta flooring in the bathroom brings warmth and old-world charm. Soaring ceilings and abundant daylight create a peaceful play of light and shadow, shifting subtly with the seasons and emphasizing the cottage’s connection to the natural landscape outside. Sleek Steel Effect Folding Patio Doors Elevate the Modern ADU Design Aesthetic Three customized steel effect folding patio doors define the living space, each aligned to respond to a different edge of the site. The largest, spanning nearly 20 feet wide and just under eight feet tall, opens directly onto the stone patio, allowing the main gathering area to extend fully into the landscape. Along the side of the living room, a smaller 10-foot-wide system introduces more light and ventilation, nearly creating an open corner condition if not for the structural post that supports the façade and roofline. At the rear, a fourth ten-foot-wide system features a French door swing panel configuration that opens toward the courtyard, strengthening the design connection to the main residence. All steel effect folding patio doors were specified with a low-maintenance, water-rated Performance Sill to safeguard against inclement weather while providing a seamless, barrier-free transition to the outdoor patio. Unique Customizations for Visual Appeal and a Steel Effect Each folding patio door system is configured to open outward, maximizing usable floor space in the compact interior and allowing furniture placement to remain uninterrupted. By stacking outward, the steel effect folding patio doors, specified in a SE Classic Bronze powder coat, ensure every inch of the cottage is optimized. Simulated divided lites create a consistent rhythm across windows and doors, maintaining alignment with the traditional barn-inspired exterior. In the bedroom, a three-panel, 10-foot-wide system mirrors these customizations, matching the steel effect divided-lite pattern and outward-opening configuration, extending the indoor-outdoor connection while preserving visual continuity throughout the ADU. “The divided lites were crucial to the architectural vision, and while budget prohibited a steel and glass system, NanaWall Systems’ thin frames provide the open and airy feeling we hoped to attain,” says Cawse. “Simulated divided lites transition the thoroughly modern element of the glass walls to remain in harmony with the otherwise traditional palette.” Matching Windows and Doors: Create a Cohesive Design Program Alongside the larger openings in the living areas and bedroom, a smaller 3-foot-tall NanaWall tilt turn window was added to the bathroom. This window-sized NanaWall system perfectly matches the divided lite panels and sleek frames of the steel effect folding patio doors, creating a cohesive modern ADU design throughout. The compact opening provides ventilation and natural light, enhancing the spa-like atmosphere along with natural stone flooring. The matching glass lines and sleek profiles of the NanaWall Generation 4 comprehensive product line further unify visual consistency, allowing each system to fit into the architectural style seamlessly. “This project had three bifold glass walls, a pair of double French doors with sidelites, and a single tilt turn window,” says architect Lauren Cawse. “Being able to work with a single manufacturer provided aesthetic cohesiveness and simplified coordination.” Sustainability Where It Matters Most New York weather can vary from hot 85-degree summers to cold 26-degree winters. Creating an efficient living space was a primary goal. To achieve this, the design included Timber HP-insulated walls and floors with a heat pump system for effective heating and cooling. Additionally, the steel effect folding patio doors and windows were specified with double-glazed panels to ensure a tight building envelope. Indoor-Outdoor Living Spaces for Relaxing and Entertaining In-house landscape designer Liz Pulver worked closely with the team to conceive open-air spaces that enhanced the connection between inside and outside. To the south end of the lot, the landscape transitions into an “enhanced meadow,” allowing the cottage to feel embedded within the surrounding fields rather than set apart from them. A circular pool was designed to mimic a natural pond with a modest footprint. Around it, a minimalist fence and sunken stone ha-ha wall offer discreet safety for young children. Limited space due to existing infrastructure and zoning setbacks left only a small footprint for the swimming pool, prompting the designer to propose a circular form that maximized the usable swimming area. “We felt that the perfect way to integrate a pool into the property and to honor the landscape would be to treat the pool as a piece of art itself,” says Pulver. “The result is a beautiful round pool that serves as both a functional retreat and a sculptural moment.” Final Thoughts: A Barn-Inspired Design for Contemporary Living This modern ADU design skillfully combines modern features with the enduring charm of traditional barns. The outcome is a welcoming living space that stands out amid a stunning landscape. Natural materials that mimic the beauty of the outdoors, expansive steel effect folding patio doors that fill the space with fresh air and natural light, and a restrained interior design work together to create an inviting retreat for everyday living, throughout the seasons. “When entering the site, the cottage feels as though it was always there,” says Cawse. “It achieves its two opposing goals by creating a feeling of intimacy and enclosure near the house while also functioning as a threshold to the expansive fields and views beyond.” Explore how NanaWall folding patio doors elevate other ADU spaces in our inspiring project photo gallery! Frequently Asked Questions (FAQs) What is Slimline Steel Effect? Steel Effect is a folding patio door design option that replicates the appearance of traditional steel-framed glass doors. It combines the look of steel with the performance benefits of aluminum, including energy efficiency, low maintenance, greater design flexibility, and lower cost. How does a NanaWall Steel Effect aluminum system compare to traditional steel-framed glass doors? NanaWall Slimline Steel Effect folding patio doors replicate the narrow frames of traditional steel doors with improved weather and thermal performance and easier operation. They are lighter, more corrosion-resistant, and feature a thermally broken design for better energy efficiency and lower long-term maintenance. What are the benefits of Steel Effect folding glass walls? Steel Effect folding glass walls deliver the narrow sightlines and grid patterns of traditional steel, combined with the performance and low maintenance of aluminum. The slimline steel effect option offers all the benefits of our Generation 4 product line, including the FourFold / SixFold floating panel set option and smooth operation with Gothic arch stainless steel rollers on a stainless steel track. Can Slimline Steel Effect glass walls be customized? Yes, these systems offer a high level of customization to suit different architectural styles, including simulated divided lites specified in various patterns, popular SE colors for a true steel effect look, and a contemporary glass stop option for a refined look. Contact your local NanaWall representative for additional options here. How energy-efficient and weather-resistant are Slimline Steel Effect folding patio doors? Steel effect folding systems are engineered for strong thermal and weather performance. Thermally broken frames and high-performance glazing help improve energy efficiency. Each NanaWall system has been independently tested for air, water, structural integrity, and forced entry with excellent results.