Residential projects form an important part of our practice, and we support homeowners throughout South Wales and the South West with a wide range of requirements. Whether the brief involves a modest single-storey extension, a full renovation or a one-off new build, we apply consistent care, expertise and personal attention. Our collaborative method recognises that successful architecture depends upon a team bringing together diverse skills and knowledge, and we aim to make the experience accessible to those unfamiliar with working with an architect. Alongside residential work, we deliver commercial projects for businesses, housing associations, councils and community organisations. Our portfolio includes award-winning social housing, industrial refurbishments, community facilities and public building remodelling, with a strong understanding of programme, budget and the needs of multiple stakeholders.
Architectural Services
We provide a complete architectural service, supporting clients from the initial concept through to construction. Our team manages the design process, coordinates with structural engineers and other consultants, and administers the building contract. This approach provides clients with one trusted point of contact throughout, ensuring comprehensive support at every stage.
Our residential architects help homeowners transform ideas into well-considered homes through extensions, renovations and new builds. We begin by understanding your property, aspirations and practical needs, then develop designs that respond to planning constraints and your budget. With more than 20 years experience, we provide professional support from early advice through planning and construction.
We deliver commercial architectural services for projects ranging from social housing and healthcare facilities to offices, community buildings, visitor attractions and light industrial environments. Our team draws on extensive sector knowledge and a strong understanding of planning requirements across South Wales and the South West. From early advice to full architectural support, we provide considered, buildable design solutions for commercial clients.
Certified Passivhaus Designers
Through our Certified Passivhaus Design service, we support new homes, residential developments, extensions and other low-energy buildings. Passivhaus principles guide the design from an early stage, addressing solar gain, orientation, insulation, airtightness, thermal bridging, high-performance windows and mechanical ventilation with heat recovery. We use specialist energy modelling to assess performance and refine the design accordingly.
Conservation and Listed Building Consents
We provide architectural services on Listed Buildings and in Conservation areas
Master Planning
We undertake feasibility studies and masterplanning with a focus on placemaking and the creation of neighbourhoods and communities. Sustainable principles remain central to our projects from the outset. We ensure sites are inherently sustainable, provide easy access to local amenities, encourage active travel, and incorporate strategic approaches to waste management.
Jul 18, 2026
From the initial consultation through to planning approval, Dennis Hellyar Architects were professional, responsive and incredibly knowledgeable. They made what could have been a stressful process feel straightforward.
Jun 29, 2026
I invited David Hellyar to my come to my home to discuss an appointment for an extension to the property. David is very professional and has significant knowledge in his field, I knew almost immediately that this would be a good fit. From my initial brief and hand sketches, his practice developed drawings, with one or two iterations at my request, and provided a package for a planning application. David made the application on my behalf along with the necessary building control requirements. I also, as an addition, asked David to source and co-ordinate with a Structural Engineer so as to provide the structural calculations for Building Control approval. I chose this route in preference to an appointed builder carrying out calculations. Planning was approved without any issues. The package provided by David was clear and concise and allowed the builder to construct without any problems. I can therefore recommend David as a thoroughly reliable and trustworthy Architect.
Jun 26, 2026
Dennis and his team are fantastic at what they do. From the initial home visit to the final drawings, they communicated well, offered suggestions towards the design that we may have not considered & genuinely cared about the project. Diolch everyone
Jun 18, 2026
I wholeheartedly recommend Dennis and the team. They were with us for every step of our design journey. Dennis helped us define what we wanted and gently explained what we could achieve given the constraints imposed by our site, budget and planning requirements. Throughout the process the team made sure we understood where things were at so the only surprises were the ones we sprung on them. Love their work!
May 22, 2026
Great advice and designs from Dennis and his team. Our kitchen and dining room renovation are just what we wanted. Many thanks
May 18, 2026
Dennis, Martin and the team were approachable, prompt and generated a range of ideas for remodelling our kitchen that we hadn't thought of and which will produce a much better result than we'd envisaged. Thank you guys.
Mar 06, 2026
I met Dennis in the context of a research project on home extensions involving HCU Hamburg and Cardiff University. We approached him because of his extensive professional experience, particularly in developing residential projects in South Wales. Dennis kindly took the time to contribute to our research, generously sharing his valuable expertise and insights into the residential projects he has worked on. He also provided us with his broader perspective on the development of the home extension and refurbishment industry.
Nov 04, 2025
Dennis was very helpful, his attention to detail was impressive and experience showed in his knowledge for the work that needed compliant designs for.
The architectural drawings supplied, showed so much detail in many ways.
I would highly recommend Dennis Hellyar Architects for all architectural designs required.
Jun 26, 2025
Dennis Hellyar Architects have delivered multiple successful projects for our Association. Their team is creative, detail oriented, and easy to work with. Every project has been completed to a high standard, on time, and with clear communication throughout. A trusted and valued partner were always happy to recommend.
#twinmotion #archcad #3drenderings of our #smallworks #extension and #remodlling #architecturalpr oject at Bishops Road, Cardiff. #arch #cardiffarchitec ts #cardiffarchitec t #homedesign #housedesign
#twinmotion #rendering3d of the front#porch at #bishopsroad. #smallworks #project nearing #completion on site, construction by @andy.j.ward. #arch #architecturedes ign #architectsuk #architectcardif f #architectscardi ff #architectsbarry #homedesign #housedesign
#schemedesign #options for #proposed #converted #coachhouse #arch #architecturedes ign #architect #pennant
#workinprogress #smallworks #architecturalpr oject nearing #practicalcomple tion on Park Road, Barry, by @blackrockcontr actors
#workinprogress #smallworks #projects at #bishopsroad nearing completion #extension #cardiffarchitec ture #barryarchitect #houserenovation #home #retrofit #arch #cedar #glazing #transformation
#smallworks project extending and remodelling. #thermowood #singleply #architecture @ Nottage https://t.co/H1Imlh0LUi
Just posted a photo @ Whitchurch, Cardiff, United Kingdom https://t.co/tKwjSfu6we
Wait until you see what we are doing with this #refurbish #retrofit #remodel #refurbishing #remodelling… https://t.co/ihxkLKm9De
Clean, simple - Stunning Weltpostpark Housing / SSA Architekten https://t.co/x1kAf9LUzp via @archdaily
More is more @jimbo2112 @barcygnusx1 @MikeTappy https://t.co/g41fjWFPzz