Dennis Hellyar Architects
Architect in Barry, Vale of Glamorgan
Dennis Hellyar Architects is a RIBA Chartered Practice based in Barry, South Wales, registered with the Architects Registration Board and accredited as Certified Passive House Designers. We bring the rigour of a bigger architecture firm with the personal service our clients value most.We work with homeowners, businesses, housing associations, and community organisations across Cardiff, the Vale of Glamorgan, Swansea, Bristol, and the wider South West, delivering practical, well-designed architecture grounded in real knowledge of the places we work in.
We believe good architecture should make life better in practical, tangible ways. Not just buildings that look good in photographs, but spaces that work well for the people who use them every day. Homes that genuinely improve how families live. Commercial buildings that help organisations do what they do better. Housing that creates places where communities can live and thrive.
Residential Architecture
We help homeowners across South Wales and the South West design homes they love. From modest single-storey extensions to full renovations and one-off new builds, we bring the same care, expertise and personal attention to every residential project. We take a collaborative approach and understand that a good project relies on a team with a broad range of skills and knowledge. The process can feel daunting if you have never worked with an architect before. We make it straightforward.
Commercial Architecture
We work with businesses, housing associations, councils and community organisations on commercial projects of all sizes. Our commercial portfolio spans award-winning social housing, industrial refurbishments, community facilities and public building remodelling. We understand what it takes to deliver a programme on budget and to multiple stakeholders' satisfaction.
Areas Served
- Cardiff Vale of Glamorgan Swansea Bristol South Wales South West
Business Details
- Serving residential, commercial and industrial clients
- Insured
- Year established: 2013
- Number of employees: 4
Highlights & Specialties
- Best Social Housing Award, Building Excellence Awards 2020, Vale of Glamorgan Council
- Formerly, Sustainability Awards in Education and Health projects (BREEAM)
- Formerly, RICS Award Winner for Loudoun Square
- Certified Passive House Designers
- Sustainability at the core of our design thinking and material choices
- The design quality and process discipline of a larger practice
- The attention to detail, personal service and cost-effectiveness of a specialist boutique studio
- Creativity at all stages - Planning, Technical, Construction and Handover
- Guidance through Planning permission, design development and construction support
- Local Knowledge That Makes a Difference
- Collaborative Approach to Design
- Reputation for Responsive, clear communication and quick turnaround on queries and changes
Professional Associations & Certifications
- RIBA Chartered Practice
- ARB Registered
- Certified Passive House Designer
Social Profiles
Contact Details
Products & Services
Architectural Services
read moreHouse Extension Design, Planning Drawings & Applications, Feasibility & Early Advice. For clients who want complete support, we offer full architectural services from initial concept through construction. We manage the design process, coordinate with structural engineers and other consultants, and administer the building contract, giving you a single, trusted point of contact throughout.Residential Architecture
read moreWe help homeowners across South Wales and the South West design homes they love. From modest single-storey extensions to full renovations and one-off new builds, we bring the same care, expertise and personal attention to every residential project. We take a collaborative approach and understand that a good project relies on a team with a broad range of skills and knowledge. The process can feel daunting if you have never worked with an architect before. We make it straightforward.Commercial Architecture
read moreWe work with businesses, housing associations, councils and community organisations on commercial projects of all sizes. Our commercial portfolio spans award-winning social housing, industrial refurbishments, community facilities and public building remodelling. We understand what it means to deliver a programme on budget and to the satisfaction of multiple stakeholders.Certified Passivhaus Designers
read moreDennis Hellyar Architects provides Certified Passivhaus Design services for clients seeking highly energy-efficient, comfortable and sustainable buildings across Cardiff, the Vale of Glamorgan and South Wales. We integrate Passivhaus principles from the earliest desiMaster Planning
read moreFeasibility studies and masterplanning, looking at placemaking and creating neighbourhoods and communities. Sustainable principles are at the heart of our projects; The site must be inherently sustainable, with easy access to local amenities, an emphasisConservation and Listed Building Consents
read moreWe provide architectural services on Listed Buildings and in Conservation areasTestimonials
Christian Bowerman
Penarth
read morePaul and I have regularly worked with Dennis and his team, and we wholeheartedly recommend their architectural services.
In the 20 years we have been trading as Atlantic Dwellings (our construction company), time and time again we have seen how Dennis and his teams innovative designs have made creative use of space and have delivered practical optimal solutions unique to each clients requirements and budget.
Dennis and his team consistently provide us clear high-quality drawings containing all the relevant technical details and information required to bring their architectural visions to life. This ensures the best outcome for the client whilst enabling us to translate their design intent into amazing spaces.
Their ability to translate clients requirements into distinctive highly functional designs while remaining price competitive is truly impressive. There flexibility, excellent communication, and collaborative approach set them apart, and we at Atlantic Dwellings would not hesitate to recommend Dennis and his team to anyone seeking innovative and reliable architectural services.
Services
Planning and zoning approval assistance, Custom home design, Architectural design services
In the 20 years we have been trading as Atlantic Dwellings (our construction company), time and time again we have seen how Dennis and his teams innovative designs have made creative use of space and have delivered practical optimal solutions unique to each clients requirements and budget.
Dennis and his team consistently provide us clear high-quality drawings containing all the relevant technical details and information required to bring their architectural visions to life. This ensures the best outcome for the client whilst enabling us to translate their design intent into amazing spaces.
Their ability to translate clients requirements into distinctive highly functional designs while remaining price competitive is truly impressive. There flexibility, excellent communication, and collaborative approach set them apart, and we at Atlantic Dwellings would not hesitate to recommend Dennis and his team to anyone seeking innovative and reliable architectural services.
Services
Planning and zoning approval assistance, Custom home design, Architectural design services
Nick Gale
Cardiff
read moreDennis and his team are fantastic at what they do. From the initial home visit to the final drawings, they communicated well, offered design suggestions we may not have considered, and genuinely cared about the project. Diolch everyone
Don Caroll
Barry, Vale Of Glamorgan
read moreI wholeheartedly recommend Dennis and the team. They were with us every step of the way. Dennis helped us define what we wanted and gently explained what we could achieve given our site, budget, and planning constraints. 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!
Nathan Jones
Barry, Vale Of Glamorgan
read moreWeve had a brilliant experience working with Dennis and the team at Dennis Hellyar Architects. The visuals they created were incredibly impressive and really brought our ideas to life. Dennis has been supportive, approachable and generous with his advice throughout the process, and its clear he genuinely cares about achieving the best outcome for his clients.
A special mention as well to Jesus and Callum both were fantastic to deal with, professional, friendly and clearly very talented. Their input made the whole experience even smoother.
Were very grateful for all the work so far and would happily recommend the whole team to anyone looking for a reliable, creative and client‑focused architectural practice. Lynne & Nathan
A special mention as well to Jesus and Callum both were fantastic to deal with, professional, friendly and clearly very talented. Their input made the whole experience even smoother.
Were very grateful for all the work so far and would happily recommend the whole team to anyone looking for a reliable, creative and client‑focused architectural practice. Lynne & Nathan
Gareth Kiddie
Barry, Vale Of Glamorgan
read moreDennis Hellyar Architects provided a brilliant service! Great designers, really efficient service and super friendly. Thanks Dennis and team. Great job 👏
Jack Crook
Pontyclun
read moreDennis Hellyar Architects have been brilliant helping us to submit an planning application, including drawings and site survey. they also acted as the go between the planning office and us. helping us to proceed smoothly and answering questions along the way. highly recommend
Alan Salisbury
Barry, Vale Of Glamorgan
read moreWe are delighted to leave a 5-star review for the design work Dennis Hellyar and his team recently completed for us. Dennis, with his knowledge and expertise, creatively gave us a variety of options to reconfigure and maximise space in our planned extension. We could never have imagined the possibilities without his input. In particular, he listened intently and was sensitive to our preliminary and emerging ideas. His advice was clear and always with our interests in mind.
We thoroughly recommend him without reservation.
Alan and Jane Salisbury
We thoroughly recommend him without reservation.
Alan and Jane Salisbury
Sarah Corner-Davies
Cardiff
read moreWe recently worked with Dennis Hellyar Architects on a Victorian property side- and rear-extension and were extremely impressed throughout the process. From the outset, they took the time to understand the property's character and our vision for the space. Their creativity, professionalism, and attention to detail really stood out.
They guided us through the planning process with clarity and confidence, making what could have been a stressful experience feel smooth and manageable. Communication was always responsive and supportive, and their knowledge and design expertise gave us real confidence at every stage.
We highly recommend Dennis Hellyar Architects to anyone looking for an architect who combines innovative design with a personable, highly professional approach.
They guided us through the planning process with clarity and confidence, making what could have been a stressful experience feel smooth and manageable. Communication was always responsive and supportive, and their knowledge and design expertise gave us real confidence at every stage.
We highly recommend Dennis Hellyar Architects to anyone looking for an architect who combines innovative design with a personable, highly professional approach.
Elizabeth Treasure
Penarth
read moreDennis Hellyar Architects provided outstanding service on my house renovation and extension. They worked through several design iterations, then secured planning permission and the contract, and have been very supportive during the post-contract phase. The work is almost finished, and I am delighted with the result. I have never done anything like this before, and I could not have done it without them. Thank you!
Robert Chapman
Bridgend
read moreExcellent service by the design team on our current project in Bridgend.
Our client changed their minds on the extension we are building from a warehouse into a manufacturing facility. After our DTM meetings, DHA revised the drawings quickly, without affecting our build programme, and with excellent communication throughout.
Hopefully we'll work together again in the future, and I would highly recommend them.
Our client changed their minds on the extension we are building from a warehouse into a manufacturing facility. After our DTM meetings, DHA revised the drawings quickly, without affecting our build programme, and with excellent communication throughout.
Hopefully we'll work together again in the future, and I would highly recommend them.
Reviews Write a Review
Diana Johnson
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.
Value for Money
Service & Support
Quality
Location
Ken Briggs
Jul 10, 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.
Value for Money
Service & Support
Quality
Location
Don Carroll
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!
Value for Money
Service & Support
Quality
Location
Alan and Jane Salisbury
Jun 11, 2026
We are delighted to be able to leave a 5 star review with regard to the design work Dennis Hellyar and his team recently completed for us. Dennis with his knowledge and expertise was able to creatively provide us with a variety of options to re-configure and maximise space within our planned extension. We could never have imagined the possibilities without his input. In particular he listened intently and was sensitive to our preliminary and emerging ideas. His advice was clear and always with our interests in mind.
We thoroughly recommend him without reservation.
We thoroughly recommend him without reservation.
Value for Money
Service & Support
Quality
Location
Steve Martin
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.
Value for Money
Service & Support
Quality
Location
Camila Penazzo
May 05, 2026
We had a great experience with this Dennis and Jesus for our measured survey. They were highly responsive, punctual, and very efficient with the turnaround. Beyond the core service, they were also incredibly helpful in suggesting other professionals to support us through the wider process. Would definitely recommend.
Value for Money
Service & Support
Quality
Location
Lucas Elsner
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.
Value for Money
Service & Support
Quality
Location
Robert Chapman
Feb 18, 2026
Excellent service by the design team on our current project in Bridgend.
Our client changed their minds on the extension we are building from a warehouse into manufacturing facility. Following our DTM meetings DHA revised the drawings in no time not for it to affect our build programme and excellent communication throughout.
Hopefully we'll work together again in the future and I would highly recommend them.
Our client changed their minds on the extension we are building from a warehouse into manufacturing facility. Following our DTM meetings DHA revised the drawings in no time not for it to affect our build programme and excellent communication throughout.
Hopefully we'll work together again in the future and I would highly recommend them.
Value for Money
Service & Support
Quality
Location
Key People
Dennis Hellyar
Principal Architect And Directorread moreDennis brings over 25 years of architectural experience working across a broad range of UK sectors, including education, commercial, residential, healthcare and mixed-use regeneration. He works closely with every project, guiding it from initial concept to completion.