DASH is a sustainable architecture and structural engineering studio founded with a mission to champion low-energy design and create healthy, beautiful buildings that benefit both people and the planet.

With the urgency of accelerating climate change impacts, we are in a dash to create affordable and sustainable buildings, there’s no time to waste!

Located in London’s Waterloo, our DASH team is led by Jonathan and Mario, who have successfully delivered over 200 residential and commercial projects worldwide.

We are in a dash to create affordable and sustainable buildings, there’s no time to waste!

Creating beautiful and comfortable buildings

At DASH, our design approach prioritises people.

We are constantly striving to deliver the highest levels of comfort, wellbeing, and performance in our work. Whether it's designing low-energy new homes, repurposing existing structures, or specifying natural materials; we create inclusive spaces for you to live, work and play.


Alternative delivery models

We understand the challenges of managing construction projects while maintaining your sustainability goals.

That's why we offer two delivery models to assist you.

Our traditional model provides single or multi-disciplinary design services for small-scale commercial schemes and residential buildings.

Our innovative DASH Home model takes your home project from design concept to completion and handover.

Passivhaus-led design

We are certified in Passivhaus design and specification, and we integrate these principles into our design thinking.

By incorporating sustainability-driven, multi-disciplinary design from the outset, we deliver the best value and results for you.

Our clients have achieved sustainability accreditations, including BREEAM, Passivhaus, Enerphit, AECB Building and Retrofit Standards.

Trusted local suppliers

Finding reliable, local contractors and suppliers who can deliver a beautiful finish can be challenging.

For your peace of mind, we have vetted local contractors and suppliers who share our sustainability and inclusivity-led design approach.

During your project, we can connect you with these trusted professionals and suppliers.

Meet the team

Mario Sacco
Dip Arch (Rome) ARB RIBA

Jonathan Fashanu
CEng MICE CEPH

  • Director

    Jonathan is a highly skilled and accomplished professional, bringing expertise as a chartered civil and structural engineer, certified Passive House designer, regenerative practitioner and project manager. With over a decade of experience in the field of engineering and construction, he has established himself as a prominent figure in the industry.

    In addition to engineering, Jonathan is passionate about sustainable design and its integration into architectural practices. He shares his knowledge and insights as an instructor on sustainable design at the prestigious Architectural Association. Jonathan's dedication to inclusivity is evident through his active involvement on the board for the Association of Black and Minority Ethnic Engineers. He consistently advocates for creating inclusive spaces, embracing regenerative design principles, and promoting awareness of neurodiversity.

  • Design Director

    Mario is an accomplished Chartered Architect, registered with both the Royal Institute of British Architects (RIBA) and the Architects Registration Board (ARB). With an extensive career spanning over 30 years, he has amassed a wealth of experience across diverse sectors, including residential, commercial, schools, and healthcare.

    Having held senior positions in renowned architectural studios based in London, Mario has played a pivotal role in shaping and delivering notable projects throughout his career. His portfolio showcases a remarkable collection of architecturally significant and successful ventures, demonstrating his unwavering commitment to design excellence and innovation.

    With his profound knowledge and expertise, Mario brings a unique perspective to every project he undertakes. His ability to understand the specific requirements of each sector and translate them into compelling architectural solutions is evident in his exceptional track record. Mario's contributions to the field of architecture have been recognised and admired by peers and clients alike.

    As a key member of our team, Mario's extensive experience and passion for architectural design enriches our studio's ability to create remarkable and transformative spaces. His visionary approach and dedication to delivering excellence continue to shape the built environment in meaningful ways.

Who we work with

Our offer for our clients, partners, and collaborators is as follows:

Large architectural practices

Experts in delivering innovative residential and small-scale commercial schemes.

Specialists in designs using natural materials such as stone and timber, enhancing your in-house team's capabilities.

Skilled in sustainability, low-energy builds, and compliance with Passivhaus and Enerphit standards.

Small-scale commercial developers & sustainable contractors

Strong understanding of the development process and efficient construction methods.

Focus on achieving project goals in the most intelligent and time-effective manner, including securing planning permissions.

Leaders in modern methods of construction and utilising healthy natural materials as part of the design process.

Eco-conscious self-builders & homeowners

Prioritise comfort and wellbeing

Team led by experienced professionals in a streamlined process

Stress free delivery model and trusted network of suppliers and contractors.

A photo of our architects and engineer all wearing dash t-shirts in a building sight

Let’s build something beautiful