Meet our firm.

We can't wait to get to know you. 


Respectful of the past, excited about the future.

Hierarchy Architecture & Design PLLC is an architecture firm based in Manhasset, NY on the north shore of Long Island. Our company specializes in creating timeless designs that are seamlessly integrated into the home and neighborhood's existing context. Aesthetically, we are known for Clean Modern designs with clean and classic proportions, as well as Transitional and Traditional home designs. We provide our clients with a wide range of architectural services from large scale projects, like brand new ground-up homes, to smaller more detailed projects like custom millwork, and everything in between including interior & gut renovationskitchen renovations and bathroom renovations. One of the more distinguished services we offer is the restoration of old Tudor and Colonial homes in the Greater New York area. Whatever your architectural needs are, we are here to help. Our support extends well beyond the design phase as we are with you at every step of the home planning, designing and construction processes. Our mission is provide a strong foundation for your dream home.

Meet our owner.

With over 30 years experience. 


Principal Architect, AIA, CKD

T.J. is the founder and Principal Architect of Hierarchy and distinguishes himself as the only Architect on Long Island who is both a member of the Architects Institute of America (AIA), and is also a Certified Kitchen Designer (CKD).

A graduate of Cornell University Art Architecture & Planning Department, and NYU Construction Management Program, T.J. has been a registered Architect in NY and NJ since the 80's.  T.J. also teaches as an Adjunct Professor at NYIT School of Architecture in Old Westbury, NY.

Originally from the Boston area, T.J. has lived in Manhasset for over 20 years, and has served on many local community boards and charities.  His passion is seeing jobs come to life and making a difference.

A commitment to excellence.

Each home is as unique as the people that live in it. 


To enhance homes and the communities they are a part of.

For over 20 years, Hierarchy has been creating, renewing, and restoring homes in the Tri-State area, adding to the regions beautiful, existing landscape. The firm has designed homes with the utmost care and precision, developing an impressive and diverse portfolio of projects mainly in traditional, transitional, and clean modern styles.


Here at Hierarchy we have long emphasized quality over quantity and have chosen to focus on a small number of projects each year. This commitment allows our team to customize each design to match the individuality of the client, ensuring that their vision comes to life. The proficiency, focus and attention of the team shines through in the finished product and has been a key factor in our firms consistent ability to wow clients.

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Hierarchy Architecture + Design PLLC | Traditional + Contemporary Designs | Long Island Architect

Respectful of the past, excited about the future

Hierarchy Architecture + Design PLLC is a Long Island architecture firm based out of Manhasset, NY, in Nassau County. Hierarchy is one of Long Island's premier architecture and design firms, with a team of  talented architects led by Principal, T.J. Costello. We specialize in providing customers with timeless architecture solutions by creating or remodeling classic homes that are seamlessly integrated into the neighborhood's existing context. Hierarchy Architecture + Design PLLC is known for designing custom residential, primary & vacation homes in modern, contemporary, traditional or transitional styles. Our team of architects has developed an impressive portfolio of projects from large scale new building, ground-up architecture projects, to smaller more detailed requests like custom millwork. The architecture firm has become known on Long Island for its seamless residential gut renovations, and Tudor restorations, creating "new-old homes" by breathing life back into  classically designed houses. The team of architects has also done interior renovations and exterior renovations or additions for many brick colonial homes in the Tri-State area.  Aside from single-family residential projects, Hierarchy has also completed multi-family housing or institutional housing projects, as well as commercial hospitality projects, such as bars and restaurants. T.J. Costello, the Principal architect for Hierarchy Architects + Designers PLLC  is the only Long Island architect who is also Certified Kitchen Designer and most home remodels that are done often include a kitchen renovation, and bath renovation.  Follow the link to learn more about the architecture and design services we offer. For additional information or to book a consultation with us, click here to contact or view our contact information.

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