Designing the interiors of duplex house presents unique opportunities and challenges, offering two levels of space to creatively enhance. When drawing inspiration from modern apartment interior design and residential apartment interior design, you can craft a duplex that is both stylish and functional, reflecting contemporary trends and personal preferences.

**Modern Apartment Interior Design** is characterized by its clean lines, open spaces, and minimalist approach. For a duplex house, this style can be applied to create a sense of seamless flow between levels while maintaining a sleek and sophisticated aesthetic. On the ground floor, consider an open-plan layout that integrates the living, dining, and kitchen areas. Use modern furniture with simple, geometric shapes and a neutral color palette to create an uncluttered and spacious feel. For the walls, opt for large, statement art pieces or abstract prints that add character without overwhelming the space. Incorporate high-quality materials like glass, metal, and polished wood to enhance the contemporary look.

On the upper level, create a serene and cohesive retreat with modern bedroom furniture and minimalist decor. Use subtle textures and colors to ensure a restful environment. Open shelving or built-in storage can help maintain the clean lines typical of modern design while maximizing space. Consider adding modern lighting fixtures, such as sleek pendant lights or recessed lighting, to highlight architectural features and add ambiance. The key is to ensure that the design remains cohesive across both levels, blending functionality with modern elegance.

**Residential Apartment Interior Design** offers a more personalized approach, often focusing on creating warm, inviting spaces that reflect the homeowner’s individual style. For a duplex house, this means designing interiors that are both comfortable and stylish, with thoughtful attention to layout and decor. In the living areas, mix and match furniture pieces to create a lived-in feel, using a combination of textures and colors to add depth and warmth. Incorporate personal touches such as family photos, custom art, or unique decor items that reflect your personality.

On the upper level, design private spaces like bedrooms and bathrooms with a focus on comfort and relaxation. Choose cozy textiles, such as plush rugs and soft bedding, to create a welcoming atmosphere. Use colors and patterns that resonate with your style, whether it’s bold and vibrant or subtle and serene. Custom cabinetry and built-in features can help maximize space and functionality, ensuring that the duplex remains organized and efficient.

Incorporate thoughtful lighting solutions throughout the duplex to enhance both functionality and ambiance. Use a mix of task, ambient, and accent lighting to create different moods and highlight key design elements. 

Both modern apartment interior design and residential apartment interior design offer valuable insights for creating a duplex house that is both stylish and functional. By blending clean, contemporary lines with personalized touches, you can create a space that is both elegant and uniquely yours.

In conclusion, designing the interiors of a duplex house allows for creative expression and functional living. By drawing from modern apartment interior design and residential apartment interior design, you can create a home that seamlessly integrates style and practicality across multiple levels. Whether you opt for a sleek, minimalist approach or a more personalized and warm environment, the right design choices will ensure that your duplex house becomes a comfortable and visually stunning living space.