Written by Albie Meziu
Managing Director, DKM Builders Oxford Ltd
A New Chapter for Sustainable Construction in Oxford
Every year, homes across Oxford and Oxfordshire are extended, renovated and modernised to better suit the needs of growing families. Kitchens become larger, lofts are transformed into additional bedrooms, layouts are opened up, and older properties are carefully restored for another generation to enjoy. These projects remain at the heart of what we do at DKM Builders Oxford Ltd, and they continue to form the foundation of our reputation as principal contractors specialising in high-quality residential construction throughout Oxford.
From period property refurbishments and structural alterations to large family extensions and complex loft conversions, our team is privileged to work on a wide range of homes across North Oxford, Summertown, Headington, Jericho, Wolvercote and the surrounding Oxfordshire villages. Every project presents its own challenges, but occasionally an opportunity comes along that represents
something far greater than another successful construction programme.
Our latest appointment on Harbord Road, North Oxford, is one of those opportunities.
Although DKM Builders currently has numerous projects progressing across Oxfordshire, including extensions, refurbishments, loft conversions and full home renovations, this project stands apart for an entirely different reason. It is not the largest house we have undertaken, nor the highest-value project currently within our portfolio. Instead, it represents something far more significant: our first opportunity to deliver an EnerPHit retrofit, combining traditional construction expertise with the latest principles in sustainable building performance.
This remarkable 1920s detached family home will undergo a complete transformation. The project includes a substantial rear extension of approximately 60 square metres, a new hip-to-gable loft conversion with a zinc-clad dormer, significant structural alterations throughout the existing property, and one of the most comprehensive energy performance upgrades currently being delivered on a private residence in North Oxford.
Unlike a conventional extension, where the primary objective is to create additional living space, an EnerPHit project seeks to transform the way an existing building performs. Every element of the building envelope is carefully considered to minimise heat loss, improve airtightness, enhance indoor air quality and dramatically reduce the energy required to heat and cool the home
throughout the year. The result is a healthier, more comfortable and significantly more energy-efficient property that is designed to perform for decades to come.
Delivering a project of this nature requires far more than excellent workmanship alone. It demands meticulous planning, exceptional attention to detail and a commitment to following the architect’s design and technical specifications with absolute precision. Every junction, every layer of insulation, every structural connection and every installation must contribute towards the overall performance of the finished building. It is this level of precision that makes EnerPHit one of the most technically demanding forms of residential construction undertaken today.
For DKM Builders Oxford Ltd, this project represents the beginning of an exciting new chapter. While our foundations have always been built upon craftsmanship, quality construction and exceptional client service, we also believe the future of residential construction in Oxford will increasingly focus on sustainability, energy efficiency and high-performance homes. We are proud to be taking that journey alongside our clients, consultants and design team, beginning with what we believe will become one of the most exciting residential retrofit projects currently under construction in North Oxford.
What Is an EnerPHit Retrofit and Why Does It Matter?
To many homeowners, the term EnerPHit may be unfamiliar. It is not simply another way of describing an
energy-efficient extension or a property with additional insulation. EnerPHit is an internationally recognised performance standard developed specifically for existing buildings that cannot realistically achieve full Passivhaus certification due to the constraints of their original construction.
Unlike a new-build home, an existing property brings decades of history with it. Walls cannot simply be rebuilt from scratch, structural elements must often remain in place, and the character of the building should be respected wherever possible. EnerPHit recognises these challenges while setting exceptionally high standards for energy performance, comfort and long-term sustainability.
Rather than focusing on individual products, EnerPHit looks at how the entire building performs as one complete system. Every component must work together to achieve the desired result. The roof, walls, floors, windows, ventilation systems and heating strategy all play a vital role in reducing energy demand while creating a healthier living environment.
On the Harbord Road project, this philosophy will be visible throughout every stage of construction.
The existing property will undergo a complete thermal transformation. High-performance insulation will dramatically improve the thermal performance of the external walls, roof and floors. Existing windows will be replaced with advanced triple-glazed units designed to minimise heat loss while allowing natural daylight to fill the home. Particular attention will be paid to eliminating
thermal bridges, areas where heat traditionally escapes through the structure, ensuring the building performs as efficiently as possible.
One of the most significant improvements will be the introduction of a Mechanical Ventilation with Heat Recovery (MVHR) system. Unlike conventional homes that rely on natural draughts and opening windows for ventilation, an MVHR system continuously supplies filtered fresh air while recovering heat from the outgoing stale air.
This creates a healthier indoor environment, improves air quality and helps maintain comfortable temperatures throughout the year without unnecessary heat loss.
Heating will also be transformed. Rather than depending on traditional fossil fuel systems, the property will utilise an air source heat pump, supported by a substantial array of solar photovoltaic (PV) panels installed on the south-facing roof. Together, these technologies will significantly reduce the home’s reliance on external energy sources while lowering both running costs and carbon emissions.
The result is not simply a house that consumes less energy. It is a home designed to provide a consistently comfortable internal environment throughout every season. During the winter months, heat is retained far more effectively than in a conventional property, creating warm, stable living conditions without excessive heating. During the summer, the same high-performance building envelope helps maintain cooler indoor temperatures, reducing overheating and improving day-to-day comfort.
For the family who will live here, the transformation extends far beyond lower energy bills. It is about creating a healthier, quieter and more enjoyable home while future-proofing the property for decades to come. For DKM Builders Oxford Ltd, it represents an opportunity to help demonstrate how traditional Oxford homes can be successfully adapted to meet the expectations of modern living without compromising their character or architectural identity.
Delivering an EnerPHit Retrofit: Why Construction Quality Is Everything
One of the biggest misconceptions surrounding sustainable construction is that achieving an EnerPHit standard is simply a matter of installing thicker insulation or purchasing more efficient products. In reality, the success of a project like this depends far less on the materials themselves and far more on the quality of the construction and the precision with which every detail is delivered.
That is where the role of the principal contractor becomes critical.
At DKM Builders Oxford Ltd, our responsibility extends far beyond managing trades and maintaining the construction programme. On a project of this complexity, every stage of the build must be carefully coordinated to ensure the architect’s vision and technical specification are delivered exactly as intended. Even the smallest deviation from the design can affect the overall performance of the building, which is why quality control will be at the centre of everything we do throughout this project.
Construction will begin with one of the most significant phases of the programme: the complete removal of the existing roof. Because the property must remain fully protected while these extensive structural works are carried out, a full scaffold system with a temporary weatherproof roof will be installed before demolition begins. This temporary structure allows our team to continue working safely and efficiently regardless of the weather, protecting both the existing building and the newly constructed elements throughout the programme.
Once the site is fully established, structural alterations will begin. New structural steelwork, engineered timber components and JJI engineered floor and roof joists will form the framework for both the new loft conversion and the rear extension. These engineered timber systems will be carefully selected by the design team to provide exceptional structural performance, improved dimensional stability and greater precision during installation. Their accuracy also supports the airtight construction methods required for an EnerPHit project.
As the new structure takes shape, every layer of the building envelope will be installed in a carefully planned sequence. Insulation systems, airtight membranes, vapour control layers and structural connections cannot simply be added at random; each element relies on the one before it being completed correctly. Every penetration through the building envelope, every service route and every junction between existing and new construction must be detailed and executed with absolute care.
Unlike many traditional building projects, where small imperfections can often be concealed during the finishing stages, high-performance construction leaves very little room for compromise. Attention to detail is not simply desirable, it is fundamental to achieving the level of performance the design has been created to deliver.
For this reason, DKM Builders will work closely with the architect, structural engineer and specialist consultants throughout the construction process, ensuring every stage is inspected, coordinated and delivered to the highest possible standard. It is this collaborative approach that gives clients confidence that the finished home will not only look exceptional but will also perform exactly as it has been designed to.
As the project progresses over the coming months, we will continue documenting each phase of construction, providing an insight into the techniques, planning and craftsmanship involved in delivering one of North Oxford’s most technically advanced residential retrofit projects. Our aim is not simply to showcase the finished result, but to educate homeowners, architects and fellow construction professionals about what is involved in delivering a truly high-performance home.
A Project That Represents More Than One Home
Every construction company has projects that stand out throughout its journey. Not always because they are the largest or the most expensive, but because they represent a turning point in the direction of the business.
For DKM Builders Oxford Ltd, Harbord Road is one of those projects.
Across Oxfordshire, our teams are typically delivering between seven and ten residential projects at any one time. These include high-quality home extensions, loft conversions, complete refurbishments, structural alterations and period property renovations. They are the projects our company has become known for, and they continue to form the foundation of our business.
Yet this project carries a different level of significance.
It represents the opportunity to combine everything we have learnt over decades of residential construction with the future of sustainable building. It allows us to demonstrate that traditional craftsmanship and modern building science are not opposing ideas, but complementary disciplines that, when brought together correctly, can create homes that are not only beautiful but perform to an exceptional standard.
This philosophy has deep roots within our company.
DKM Builders Oxford Ltd was founded by my father, Dali Meziu, whose reputation was built on craftsmanship, honesty and delivering high-quality construction throughout Oxfordshire. Long before energy-efficient construction became part of everyday conversation, our family was restoring and improving homes with the belief that quality workmanship should stand the test of time.
That commitment has been passed from one generation to the next.
Today, while we continue to carry forward those traditional values, our responsibility is also to prepare the business for the future of residential construction. The industry is changing rapidly. Homeowners are becoming increasingly aware of energy performance, long-term running costs, indoor air quality and environmental responsibility.
Architects are designing increasingly sophisticated buildings, and construction companies must evolve alongside them if they are to continue delivering projects to the highest standards.
This is precisely why Harbord Road means so much to us.
It is an opportunity not only to construct an exceptional family home but also to expand our knowledge, refine our skills and strengthen our capability as principal contractors delivering complex, high-performance residential projects across Oxford.
As Managing Director of DKM Builders Oxford Ltd, I see this project as an investment in the future of our company just as much as it is an investment in one family’s home.
While our teams continue delivering outstanding projects across Oxfordshire every day, I believe sustainable construction, deep retrofit and EnerPHit principles will become an increasingly important part of residential building over the coming years. My commitment is to continue investing in education, professional development and practical experience so that DKM Builders remains at the forefront of that evolution.
Our ambition is not simply to build more houses.
Our ambition is to help shape the future of how homes across Oxford are renovated, improved and preserved for generations to come.
Harbord Road marks the beginning of that journey, and we are proud to have been entrusted with delivering it.
A Personal Perspective: Building on My Family’s Legacy While Looking Towards the Future
There are moments in every career that quietly redefine the direction you want to take. They are not always the biggest projects, nor the most valuable, but they leave a lasting impression because they challenge you to think differently, to learn more and to become better at what you do.
For me, Harbord Road is one of those moments.
As Managing Director of DKM Builders Oxford Ltd, I have the privilege of overseeing a company that is continually delivering residential construction projects throughout Oxfordshire. At any given time, we are managing between seven and ten live projects, ranging from substantial house extensions and loft conversions to complete refurbishments, structural alterations and restoration works. Every one of those projects carries the same responsibility. Every homeowner has trusted us with one of their most valuable assets, and that trust is something I never take for granted.
Yet despite the scale and variety of the work we undertake, Harbord Road has become the project that I find myself thinking about the most.
Not because it is the largest project in our portfolio.
Not because it carries the highest contract value.
But because I genuinely believe it represents the direction in which residential construction is heading.
Construction has always been part of my family’s life. DKM Builders was founded by my father, Dali Meziu, whose reputation was built on honesty, exceptional workmanship and a belief that quality should never be compromised. Long before discussions about building performance, airtightness and sustainable construction became common within our industry, those principles formed the foundation of our company.
Previous generations of our family were also involved in traditional construction and heritage restoration. They worked on buildings that had already stood for generations, where respecting the existing structure, understanding traditional materials and paying attention to the smallest details were essential parts of the craft. Those values have never left us, and they continue to influence the way we approach every project today.
I have never seen sustainable construction as a replacement for traditional building methods.
I see it as the next chapter.
The craftsmanship that restored historic buildings is the very same craftsmanship required to deliver a successful EnerPHit retrofit. The difference is that today’s builders must also understand building physics, thermal performance, airtightness, moisture control and the science
that allows existing homes to perform at a level unimaginable when they were first constructed.
That is why I have personally committed to continuing my education within this field.
Alongside managing DKM Builders and overseeing our live projects, I continue to invest my own time in learning about EnerPHit, high-performance residential construction and sustainable building practices. I firmly believe that the best contractors never stop learning. Construction evolves every year, and if we expect our clients to place their confidence in us, we have a responsibility to remain at the forefront of our profession.
My ambition for DKM Builders has never simply been to become a larger construction company.
It is to become a better one.
A company recognised not only for exceptional craftsmanship, but also for technical knowledge, professional management and an unwavering commitment to delivering homes that improve the lives of the families who live within them.
If, over the coming years, DKM Builders becomes recognised across Oxfordshire as a trusted contractor for EnerPHit retrofits, sustainable home renovations and high-performance residential construction, it will not be because we claimed that position. It will be because we earned it, one project, one client and one successful delivery at a time.
Harbord Road is the beginning of that journey.
It is a project that will undoubtedly challenge us, teach us and help shape the future of our company. Most importantly, it gives us the opportunity to deliver a home that will provide its owners with greater comfort, significantly improved energy performance and a healthier environment for many years to come.
For me, that is what good construction has always been about.
Not simply building houses.
But improving the way people live.
Looking Beyond Harbord Road: What This Means for Homeowners Across Oxford
Although Harbord Road is a single project, its significance extends far beyond one family home in North Oxford.
Across the city, thousands of properties were built during the Victorian, Edwardian and inter-war periods. These homes contribute enormously to Oxford’s character and architectural identity, yet many were constructed at a time when energy performance, insulation standards and airtightness simply were not priorities. They remain wonderful places to live, but many homeowners are now facing rising energy costs, ageing building fabric and increasing pressure to make their homes more sustainable without compromising their character.
For many years, the natural response was to extend.
Additional bedrooms, larger kitchens and open-plan family spaces transformed the way people lived while increasing
the value of their property. Those projects remain an important part of residential construction and continue to be a core service delivered by DKM Builders throughout Oxford and Oxfordshire.
However, the conversation is changing.
Increasingly, homeowners are asking not only how they can create more space, but how they can create a home that performs better.
A home that remains consistently warm during winter without excessive heating.
A home that stays naturally cooler during increasingly warmer summers.
A home with cleaner indoor air, lower running costs and significantly reduced energy consumption.
This shift in thinking is likely to influence residential construction for many years to come.
As environmental awareness grows and building technology continues to evolve, more homeowners will begin looking beyond traditional renovation and towards comprehensive, performance-led refurbishment. Rather than replacing existing homes, they will seek to improve them, preserving the buildings that give Oxford its unique character while preparing them for the future.
Projects such as Harbord Road demonstrate that these ambitions are achievable.
They show that a family home built almost a century ago can be transformed into a modern, high-performance
property without losing the qualities that made it special in the first place.
They also demonstrate that sustainable construction is not about following trends.
It is about making better decisions. Better decisions for homeowners.
Better decisions for future generations.
And better decisions for the long-term performance of our built environment.
At DKM Builders Oxford Ltd, we see this as a natural evolution of residential construction. The principles of quality workmanship, careful planning and attention to detail remain exactly the same as they have always been. The difference is that today’s projects demand a deeper understanding of how buildings function as complete systems rather than collections of individual components.
That is why collaboration has become more important than ever before.
An EnerPHit retrofit cannot be delivered by one individual alone. Success depends upon architects, structural engineers, energy consultants, specialist manufacturers, Building Control professionals and skilled tradespeople all working towards a common objective. Every discipline contributes to the overall success of the project, and every stage relies upon communication, coordination and a shared commitment to excellence.
As Principal Contractor, DKM Builders is proud to lead that process on Harbord Road.
Our role is not simply to construct what has been designed, but to coordinate every aspect of delivery, maintain the highest standards of quality and ensure the finished home performs exactly as intended.
While Harbord Road marks the beginning of our journey into EnerPHit construction, it is by no means the destination.
It represents another step in our continual development as a company that embraces innovation without losing sight of the traditional craftsmanship upon which DKM Builders was built.
As we continue to deliver projects across Oxfordshire, our commitment remains unchanged: to build homes with integrity, manage projects professionally and continually invest in the knowledge, people and technologies that will shape the future of residential construction.
For our clients, that means confidence.
For our team, it means continual improvement.
For DKM Builders, it means building not only for today, but for generations to come.
Conclusion: Building Better Homes for the Next Generation
Every construction project eventually reaches the same milestone.
The scaffolding is dismantled, the temporary roof is removed, the final tools leave site and the construction team moves on to the next challenge. For most people, that marks the end of the story.
In reality, it is only the beginning.
Long after the final inspection has taken place and the last tradesperson has left site, the building continues to perform. Every decision made throughout design and construction begins to influence the daily lives of the family who call it home. The quality of the indoor air, the comfort experienced during the coldest winter mornings, the stability of internal temperatures throughout the summer, and the long-term energy performance of the property all become part of everyday life.
That is the true measure of successful construction.
At DKM Builders Oxford Ltd, we have always believed that building homes is about far more than bricks, timber and steel. It is about creating places where families will build memories, celebrate milestones and live comfortably for many decades. Every extension we construct, every loft conversion we complete and every refurbishment we deliver carries that same responsibility.
Harbord Road represents an important moment in our company’s journey because it reflects where we believe residential construction is heading. While traditional extensions and renovations will always remain at the heart
of our work, we also recognise that homeowners are increasingly looking beyond additional space. They are looking for homes that perform better, consume less energy, provide healthier living environments and are prepared for the future.
We believe sustainable construction should never compromise craftsmanship.
Likewise, modern building science should never replace the traditional skills that have defined great builders for generations.
The future lies in combining both.
By bringing together exceptional workmanship, careful planning, technical understanding and a genuine commitment to continuous learning, construction companies have an opportunity to transform not only the appearance of existing homes but also the way those homes perform for generations to come.
For DKM Builders, Harbord Road is far more than another completed project that will eventually be added to our portfolio.
It is the beginning of a new chapter.
A chapter that reflects our ambition to continue investing in education, embracing innovation and working alongside talented architects, engineers and specialist consultants to deliver increasingly sophisticated residential projects throughout Oxford and Oxfordshire.
As Managing Director, I see our responsibility extending well beyond delivering today’s construction projects. My responsibility is to ensure that DKM Builders continues evolving without ever losing sight of the principles upon which the company was founded. Those principles were established by my father, Dali Meziu, and they continue to guide every decision we make today: honesty, integrity, exceptional workmanship and treating every client’s home with the care and respect it deserves.
While this is our first EnerPHit retrofit, I sincerely hope it is the first of many.
Every project teaches us something new. Every challenge makes us better builders. Every collaboration strengthens our understanding of modern construction. My commitment is to continue investing in knowledge, developing our team and embracing the technologies that will shape the future of residential building.
If, in years to come, DKM Builders becomes recognised throughout Oxfordshire as a trusted principal contractor for sustainable construction, high-performance residential renovation and EnerPHit retrofit projects, it will not be because we set out to make bold claims.
It will be because we earned that reputation through consistency, professionalism, continuous improvement and the successful delivery of every project entrusted to our team.
For us, Harbord Road is not the destination.
It is simply the first step towards what comes next.
Because the future of construction is not about building bigger homes.
It is about building better ones.
About the Author
Albie Meziu is the Managing Director of DKM Builders Oxford Ltd, a family-led principal contractor based in Oxford, specialising in high-quality house extensions, loft conversions, complete home refurbishments, structural alterations, heritage restoration and sustainable residential construction throughout Oxford and Oxfordshire.
Founded by Dali Meziu, DKM Builders has grown through a reputation for exceptional craftsmanship, honesty and delivering residential construction projects to the highest standards. Today, Dali remains actively involved in the business, working alongside his brothers, who continue to play an integral role in both construction management and hands-on site operations. Their combined experience, practical knowledge and commitment to quality continue to form the foundations of the company.
Representing the next generation of the family business, Albie leads the day-to-day operations of DKM Builders while building upon the values established by his father. Alongside overseeing multiple residential projects across Oxfordshire, his focus is on guiding the company into the future of sustainable construction through continual investment in education, professional development and modern building practices.
Supported by an experienced in-house workforce and a carefully selected network of trusted subcontractors, DKM Builders delivers a diverse range of residential projects, from period property refurbishments and heritage restorations to contemporary extensions, loft conversions and technically demanding high-performance home renovations. Every project is approached with meticulous planning, clear communication and an uncompromising commitment to quality.
The company has established strong working relationships with architects, structural engineers, planning consultants, interior designers and specialist manufacturers across Oxfordshire. DKM Builders believes that the best residential projects are delivered through collaboration, mutual respect and a shared commitment to excellence, and the company continues to welcome opportunities to develop new partnerships with architects, designers and industry professionals who share those values.
Looking ahead, Albie’s ambition is to continue expanding DKM Builders’ expertise in EnerPHit retrofits, sustainable residential construction and high-performance home renovation, while remaining true to the craftsmanship and integrity that have defined the company since it was founded. His vision is to help shape the future of residential construction across Oxfordshire by combining generations of traditional building knowledge with the innovation, technical understanding and professionalism demanded by modern homes.
