



Architectural Design for Extensions, Conversions & Internal Alterations
Clear advice. Practical solutions. Personal service.
Chartered Architectural Technologist with over 40 years’ experience.
Providing architectural services for homeowners across Donaghadee, Bangor, Holywood, Newtownards, North Down and Northern Ireland.
Why homeowners Choose GT Building Design
Over 40 years’ experience
Domestic architectural design specialising in extensions, conversions and internal alterations.
Chartered Architectural Technologist
Professional, compliant design that satisfies Planning and Building Control requirements.
Clear, fixed fees
Transparent proposals with no VAT and no unexpected extras.
Planning & Building Control
Applications prepared and submitted for you, with guidance at every stage.
A dedicated domestic specialist
Practical, well‑considered design focused on how you live and what your home needs.
What Clients Say


Albert M
"Glenn recently completed the design and architectural work for me taking his detailed drawings right through the planning office process and building control.
From the moment I met with Glenn at my property I felt comfortable. Glenn has been doing design and the architectural drawings for more than 35 years. It’s easy to tell he takes great pride in his work and will take the time to get it just right for you with your feedback.
His drawings are very detailed that in my case it enabled the planning office to grant the approval without changes. Great job Glenn."

Tommy C
"Embarking on any building project can be a very daunting task…
From the outset Glenn impressed us with his knowledge, professional approach and enthusiasm for our project.
He designed us the ideal home making full and best use of our site. Importantly Glenn also produced a comprehensive 34‑page tender document covering all aspects of the build that proved to be invaluable.
We thank Glenn hugely for helping us with what could have been a very stressful experience, and helping us achieve our dream home."

Ross M
“I got in touch with GT Building Design about the possibility of a kitchen extension…
Right from the first email, I knew Glenn was the right man for our project.
Glenn’s final plans for our project are extremely detailed and they sailed through planning and building control with ease due to his extensive knowledge and experience.
We cannot wait to begin work on our dream kitchen space and we have nothing but good words to say about working with GT Building Design.”
Architectural Services for Home Extensions & Domestic Projects
GT Building Design specialises in domestic architectural design, providing clear, practical guidance for homeowners planning to improve and extend their homes. Every project is tailored to your property, your needs and your budget.
Practical, cost‑aware design that adds space, light and value.
Unlock unused roof space with efficient, compliant design options.
Transform an underused garage into warm, comfortable living space.
Improve flow, light & functionality with thoughtful internal changes.
Planning & Building Control Approvals
Full preparation and submission of all drawings and documents.
Your Home Extension & Design Process. Step by Step
A Clear, Structured Path From First Call to Securing Approvals
1. Introductory Call
A friendly conversation to understand your ideas and outline what’s realistically achievable.
2. Written Fee Proposal
A clear, stage‑by‑stage proposal with transparent pricing.
3. Measured Survey
A measured survey of your home to produce existing plans, elevations before design work begins.
4. Concept Design
Refined, practical design options that balance creativity, compliance, cost‑awareness, tailored to your wishes.
5. Planning Application
Preparation and submission of all drawings, documents and all communication with Planning handled for you.
6. Building Control Application
Fully detailed, compliant technical drawings that give builders clear instructions.
About GT Building Design
GT Building Design was established by Glenn Thompson MCIAT, a Chartered Architectural Technologist with over 40 years’ experience in residential architecture. I provide creative, cost‑aware design solutions and guide homeowners from initial ideas through to Planning and Building Control approvals. Every project is personally managed to ensure clarity, communication and a design tailored to your home.
Awards & Recognition
Recognised for excellence in residential architecture throughout Northern Ireland:
%2007_edited_edited_edited_pn.png)