Ethos

About Our Full-Service Interior Design Firm

Margaret Costello Interiors & Design Studio is a premier, full-service interior design firm serving luxury residences throughout the US including New York, Connecticut, Florida, and California including areas like Manhattan, Los Angeles, the Hamptons, Long Island, Palm Beach, Naples, and surrounding areas. We are open to go wherever a project brings us- whether in the US or internationally.

With a focus on timeless, artisan design, we transform your vision into custom spaces that inspire and elevate your everyday life

Our Approach

At Margaret Costello Interiors, we believe every project should be as unique as the people who live in it. Our full-service interior design and project management ensure a seamless process, from concept to completion. Whether you’re building a new custom home, remodeling an existing property, or refining your interiors with hand-selected finishes and furnishings, we are your partner in creating a home that reflects your personal story.

Our full-service interior design services include:

New Construction Project Management

• Selecting, overseeing and collaborating with architects, contractors, landscape architects, and art consultants to bring your vision to life.

Luxury Interior Renovations

• Redesigning existing spaces with floor plan layouts, selection of finishes and fixtures, custom millwork, custom furniture, and coordination of delivery and installation.

Interior Furnishings and Décor

• Curating bespoke furniture, custom millwork, lighting fixtures, window coverings, rugs and décor to create refined, livable spaces

Finishing Touches

• Selecting art, textiles, and accessories for a cohesive design that speaks to your personal taste.

Designing with You in Mind

Our philosophy is rooted in creating spaces that:

1. Balance form and function, creating luxurious yet livable spaces. 
2. Uncover your personal style, avoiding fleeting trends. 
3. Celebrate texture and craftsmanship, incorporating artisanal elements that add warmth and depth to every room. 
4. Prioritize your wellbeing through the use of natural materials and soothing layouts. 
5. Bring your vision to life through thoughtful, intentional design.

Why Work with Margaret Costello Interiors and Design Studio?

We are more than just a design firm—we are your advocate, guide, and project manager. Every detail is handled with care, from sourcing unique materials to managing deliveries and installations. Our transparent process ensures there are no surprises: nothing is ordered or implemented without your approval.

Recognition and Expertise

Our work has been featured in leading publications, including Architectural Digest, Elle Decor, Dwell, PureWow, and Florida Design. Margaret Costello Interiors is proud to be a trusted partner for discerning clients who value craftsmanship, attention to detail, and a seamless design experience.