Siphonic Drainage for Revolutionary Service Station in Essex

Photo of the Gridserve Forecourt in Braintree Essex

Gridserve Braintree, Essex

  • Project
    Braintree Gridserve Forecourt
  • Client
  • Design Team
    ESS Modular
  • Technology
  • Scope
    Design, off-site fabrication, Installation


In Braintree, an hour outside London, the UK’s first Electric Forecourt was opened by Gridserve in December 2020. The station offers a state-of-the-art, electric vehicle charging-station for up to 36 vehicles. The company is aiming to build additional charging stations across the UK ahead of the 2030 ban on petrol and diesel cars. ESS Modular was chosen as the lead construction partner for this ground-breaking project.


As a two-storey building in Britain’s famous wet climate, this service station required a robust drainage system. It would be a modular build with a fresh, contemporary design as you would expect with a major renewable energy project. For the drainage specialist chosen, there were a number of challenges and considerations to take on board. ESS is a Modular Construction Market leader and expected that the system would be 90% built off-site in factory conditions ensuring only the highest level of precision and quality.

The build designers specified no piping internally, to both maximise space and match the building’s aesthetics. No visible piping on the outside was also a prerequisite, ensuring a clean look-and-feel. In practical terms, the key challenge was to ensure all piping was kept within the structure cavity. In this overall context, Siphonic Drainage was chosen as it offered significant advantages in terms of costs savings and use of space.

The main contractors also required a high level of collaboration and expected the drainage design-and-build team to work closely with their own project team in multiple locations. This project required the experience and expertise of a proven Siphonic Drainage specialist. Thanks to our solid track-record, our team at Capcon was chosen as the specialist to work on what would be the UK’s first electric forecourt.


Innovative Design

Working closely with the team at ESS, we set to work designing a siphonic drainage system that would be unique to this pioneering building-of-the-future. A modern structure meeting the fuelling needs of electric vehicles needed a look-and-feel that matched its contemporary, progressive outlook.

In practical terms, our design work was focussed on making sure pipework was unseen where possible, both inside and outside the structure. Like all projects, flexibility, collaboration, and shared knowledge was key to delivering precise plans and solutions to challenges as they arose, both off-site and onsite.

Using tools like Revit alongside other supporting building methodologies ensured the design phase was underpinned by technology-driven accuracy and precision. Our in-house quality management team was in place to sign-off and certify all plans and design work in a timely and efficient manner.

Robust Prefabrication

For this project, we prefabricated 90% of the pipework in advance in ESS Modular. And in line with all modular construction, factory conditions consistently deliver a higher quality and better performing solution compared with attempting to produce the same piping on-site.

Time is always a key issue on modern construction sites and the more work completed off-site, the less time we needed to spend on-site. In this case, it leaves the site free for other teams covering everything from groundwork to electrical engineering and power cabling. By its nature, modular construction means that nobody needs to be on-site unless it’s absolute necessary which results in more room to work and operate for those that are. Overall, the modular method always leads to a more efficiently-run site and project.

Precision Installation

On all Capcon projects, collaboration always proves to be the foundation of everything we do. And by working closely with ESS, we could begin the installation phase.

Initially, we got to work hanging the 150m of piping. Our first task was to fix our support brackets to the inner leaf of the cavity at regular intervals. Following this, we were able to hang our horizontal and vertical pipework. The horizontal pipework was supported with a continuous unistrut rail system and fixed back to the structure for optimum performance & security. Finally, we were able to join the pipework to the siphonic outlets on the roof, which had been already installed by our construction partner. All work was kept within the cavity on the superstructure as required, with our largest pipe just 56mm in diameter, taking up as little space as possible.

With much of the installation hard work already done off-site, we had just 10% of the project to install on-site and we were able to complete it in just one day. An e-car charging station requires many specialist trades, engineers and technicians working together in close proximity. Thanks to our substantial expertise in Siphonic Drainage projects of all sizes and scales, we understood the importance of working closely with all partners and stakeholders throughout to ensure a successful project was installed on time and on budget.


  • 150m of Pipework
    150m pipework designed, prefabricated, and installed on this project
  • 4
    4 Independent Systems
    Designed, pre-fabricated, installed, air-tested and commissioned
  • Reduced Costs
    20% reduction in costs compared with a traditional gravity system
  • 700 Million Litres / Year
    System designed to cater for over 700 million litres of rainwater per year

Photography from Gridserve website.