Part S of the Building Regulations is still something of a mystery to many architects, property developers and M&E contractors, says Cris Chapman, managing director of Sevadis. Here, he provides an overview of the regulations and explains why failing to meet the requirements could add significant time and cost to projects.
The transition to electrification is no longer a vague ambition, it’s a regulatory, commercial and infrastructural reality reshaping the built environment. For developers of housing estates, business parks and retail schemes, the introduction of Part S to the Building Regulations marks a significant shift in expectations around electric vehicle (EV) infrastructure. Yet, despite its importance, understanding of the regulation remains uneven across the industry.
Milestones to electrification
The trajectory toward EV-ready buildings began with the UK government’s 2019 announcement outlining its intention to mandate EV charge point provision in all new developments. This policy direction was designed to support the broader decarbonisation of transport and prepare the built environment for mass EV adoption.
This ambition has since been reinforced at a European level. The 2025 update to the Energy Performance of Buildings Directive (EPBD) introduces more stringent requirements for EV infrastructure across member states, signalling a continent-wide alignment on the issue, even as the UK operates outside the EU framework.
A key domestic milestone followed in June 2022, when Part S of the Building Regulations was formally introduced. However, a delayed implementation period and transitional provisions for projects already in the pipeline have led to gaps in awareness and compliance. Many developments currently reaching completion were started before Part S was fully understood, creating friction around initial design intent and current regulatory expectation. The ‘honeymoon period’ is definitely over – and developers need to demonstrate a clear understanding of the principles and practices of Part S.
Lack of infrastructure?
The urgency behind Part S becomes clearer when viewed against market data. According to the Society of Motor Manufacturers and Traders (SMMT), the ratio of public charge points to EVs in the UK is actually declining. While charge point numbers are increasing in absolute terms, EV adoption is accelerating at a faster rate. To put it another way, while the European average is six EVs per charge point, the UK is currently lagging behind with 17 EVs per charge point.
This imbalance is precisely what policymakers are seeking to address. Without intervention, infrastructure shortfalls risk undermining consumer confidence and slowing the transition.
Looking ahead, projected EV sales growth suggests that pressure on infrastructure will only intensify. For developers, this translates into a clear expectation: new buildings must not only accommodate current demand, but anticipate future capacity requirements.
Understanding Part S: core requirements
For such an apparently innocuous part of the Building Regulations that has been somewhat overlooked by many, the practical implementation of Part S is far from simple. It requires careful consideration as it can apply to a range of development scenarios, each with distinct obligations. Below is a broad outline of the key requirements of the regulations.
New residential buildings with associated parking must include at least one EV charge point per dwelling. This requirement applies whether the parking is within the curtilage or in a nearby allocated space. However, for commercial buildings, the regulation not only requires at least one charge point, but also cable routes for a defined proportion of parking spaces. This ensures both immediate provision and future scalability.
Where a building is subject to significant works and includes more than 10 parking spaces, developers must install charge points and enabling infrastructure, subject to feasibility and cost thresholds.
Change of use is another aspect of the regulations which has been overlooked by some developers. Buildings undergoing a material change of use (typically office to residential) are also captured under Part S, triggering similar requirements to new-build scenarios. It should also be noted that mixed used developments, combining residential and commercial, must meet the relevant requirements for each component, often creating complex compliance scenarios within a single project.
Read the small print
While the headline requirements may appear straightforward, Part S is defined by its nuances and it is here that many developers encounter difficulties.
One example concerns the interpretation of a “major renovation”. Here, the definition hinges on whether works affect a significant proportion of the building envelope or technical systems. However, readings of the regs can vary, particularly in phased developments or partial refurbishments.
Certain buildings are exempt, including those without associated parking, small-scale developments, and some listed or conservation-sensitive properties. Determining eligibility requires careful reading of both Part S and associated planning constraints.
A key provision is the £3,600 per charge point cost cap, intended to prevent disproportionate financial burden. In practice, this cap includes not just the hardware, but also enabling works such as cabling and grid connection. For sites with constrained power supply or complex layouts, costs can quickly exceed this threshold, raising questions about how much infrastructure must be delivered.
M&E considerations
Compliance is not simply about installing charge points, it is about delivering systems that meet technical standards. This includes adequate power output to support modern EV charging, dedicated electrical circuits and adherence to BS EN 61851 (which governs charging system safety and performance).
These requirements have significant implications for electrical design, load management and coordination with distribution network operators.
Subterranean parking presents additional challenges, including ventilation, fire safety, and cable routing. Integrating EV infrastructure into these environments often requires early-stage design coordination and can have cost and programme impacts if addressed too late.
A changing compliance landscape
One of the most significant developments since the introduction of Part S is the increasing scrutiny applied during the approval process. The fledgling Building Safety Regulator (BSR) and building control bodies are now more rigorously assessing EV infrastructure compliance.
As a result, projects are beginning to fail at gateway stages due to inadequate or poorly evidenced adherence to Part S. In many cases, the issue is not outright non-compliance but a lack of detailed documentation or misunderstanding of the requirements.
The realities of Part S are far more complex than many developers initially assumed. What might appear to be a straightforward requirement (installing EV charge points) quickly becomes a multidisciplinary challenge involving planning, electrical engineering, cost management and regulatory interpretation.
With EV adoption continuing to accelerate and scrutiny increasing, developers can no longer afford to treat EV infrastructure as a secondary consideration. Instead, it must be embedded into the design process from the outset.
Crucially, successful delivery increasingly depends on collaboration. Working in partnership with experienced EV infrastructure providers, those with a deep understanding of Part S and related standards, can help developers navigate the regulatory landscape, avoid costly redesigns and ensure projects meet both current requirements and future demand.
In an industry defined by detail, Part S is a reminder that compliance is not just about meeting minimum standards, it is about understanding the system as a whole.