At De Simone Designs, we believe that every project tells a story — one of innovation, collaboration, and bringing ideas to life. Founded by principal designer Thomas De Simone after 11 years working alongside local architects, the firm pairs a strong foundation in construction and the Ontario Building Code with a specialty in residential design.
All design services are provided under BCIN qualifications & within the exemptions of the Architects Act
Your vision is at the heart of everything we do. We take the time to understand your needs, preferences, and goals, ensuring that the final design reflects your unique story.
We prioritize quality and creativity, crafting spaces that are both functional and inspiring. Every project balances innovation with timeless design principles.
Adhering to the Ontario Building Code (OBC) is non-negotiable. Our work meets and exceeds regulatory standards to ensure safety, efficiency, and lasting val.
Every project we take on starts with a vision & a story. Our role is to bring that story to life through thoughtful design, careful planning, and a commitment to getting every detail right.
Thomas De Simone Principal Designer & Architectural Technologist
Registered Architectural Technologist with Association Architectural Technologists of Ontario
Fully Insured and BCIN Certified by the Ontario Ministry of Municipal Housing & Affairs
Gold Winner of the CommunityVotes Niagara Region 2026
Thomas De Simone enters the architectural design industry, beginning a career spanning projects from assembly to industrial, small to large scale.
Spends 11 years working alongside local architects, building a strong foundation in residential and commercial design, construction practices, and the Ontario Building Code.
Thomas launches De Simone Designs as owner and principal designer — licensed by the AATO, registered with the Ministry of Municipal Affairs and Housing (BCIN), and fully insured.
Pairs deep construction knowledge with a strong design sense to deliver clients truly exceptional projects — exceeding the client’s wishes, highlighting the design integrity of the existing building, and meeting all OBC requirements without sacrificing aesthetics.
Completes a range of residential and commercial projects of varying scale — from townhouse developments to custom residential and commercial new builds — with ongoing expansion into multi-unit and mixed-use, plus regular developer consulting on feasibility studies and early-stage site analyses.
From the first meeting, we keep every client well informed through each design and planning phase, with every project carefully thought out, reviewed, and designed around your satisfaction.
We look forward to being part of designing your future dream or investment projects.
We give developers and builders clear, well-coordinated documentation that supports smooth approvals and efficient construction. Our drawings are prepared with a strong understanding of municipal review processes — reducing permit delays, minimizing zoning-related redesign, and limiting unnecessary consultant back-and-forth. Unlike standard “permit-only” packages, our construction documents carry a high level of detail to minimize on-site uncertainty and RFIs.
The result: we act not just as designers, but as strategic partners — helping clients make informed decisions and achieve successful, buildable outcomes.
Architecture Drawings & Visualisation
At De Simone Designs, we share a common goal: creating spaces that improve how people live, work, and connect. Joining our team means being part of a collaborative environment where creativity, technical skill, and attention to detail come together on every project.
We worked with Thomas for our custom cottage project. His creativity, thought-out plans and dedication to creating a great design truly exceeded our expectations. From the initial consultation to the final result, Thomas was professional, knowledgeable, and truly passionate about his work. He listened to our ideas and brought them to life. If you are looking for an architectural design firm that will go above and beyond to create your dream space, look no further than De Simone Designs. Thank you for making my dream summer cottage a reality!
C & J Keast – Crystal Beach, ON
We used De Simone Designs for a rear addition project to our existing home. We were very happy with the great design, but even happier that they also kept us within our budget. Thomas worked out all the tricky construction details, which was a huge relief for first time renovators navigating the world of construction. His attention to detail and ability to balance aesthetics with practicality was truly impressive. What stood out the most to me was his willingness to guide us throughout the entire process. As someone who is not well-versed in architectural design or construction, I appreciated his expertise and his ability to explain things in a way that was easy to understand. He truly made the entire experience stress-free and enjoyable. I highly recommend this firm to anyone in need of an architectural designer.
F & P Roveda
It was a pleasure working with Thomas at De Simone Designs. We appreciated his fun approach to construction and design, as well as all the energy and work he put in to our detached garage project. The added space for my wife’s art studio on the second floor was amazing touch we hadn’t initially thought of. We were very pleased with this professionalism and the quality of his work. He presented different design options and took the time to review different colour options for the exterior. His professionalism, creativity, and commitment to his clients is truly unmatched.
M & J Quevedo – Niagara Falls, ON
I contacted Thomas for the plans for a renovation of my basement to add a new secondary apartment; I couldn’t have been happier with the results. His expertise in building and city codes was evident throughout the entire process, ensuring that all aspects of the design were up to standard. I was impressed by his office’s detailed drawings, which were not only aesthetically pleasing but also had a practical and functional layout. Thomas’ friendly and fun demeanor helped make this an enjoyable process. I will always recommend him.
D Pitt – Hamilton, ON
