NPSA is the UK’s national technical authority for physical and personnel protective security, and its mission is to make the UK less vulnerable and more resilient to national security threats. Here Patricia Brown reflects on a recent opportunity to put their HVM guide into practice.
The message from my neighbour arrived while I was heading to a workshop. Matthew was planning some noisy tasks at home and apologised in advance for any inconvenience. Grateful for his consideration, it left me musing about the importance of being a good neighbour.
Little did I know that a few hours later I would hear that very thought verbalised in the workshop I was leading. In this case, neighbourliness was being applied to the weightier topic of thwarting vehicle-borne attacks.
People who threaten our safety, including using vehicle attacks, do not stop at property boundaries. Yet too often, protective security measures do exactly that – addressing threats site-by-site.
NPSA’s Public Realm Design Guide For Hostile Vehicle Mitigation (HVM) sets out a different approach. It urges anyone considering security to look at different scales when planning protective measures: District; Threshold; Site. This requires early intervention in any wider-scale development or public realm proposal, and sustained collaboration between neighbouring stakeholders. The workshop was organised to do just that.
Putting principles into practice
Knightsbridge draws visitors from across the globe to stay, shop, or just experience its iconic landmarks. It is a major contributor to the UK economy, while thousands of residents call it home. The A4, part of London’s strategic road network, bisects the area. This all contributes to competing forces and needs.
It is for this reason that the Knightsbridge Partnership – the area’s business improvement district (BID) – is planning to improve the experience for everyone through a comprehensive place and public realm strategy.
The flagship stores, hotels and other major venues in the area already have a variety of protection. Yet the scale of the remodelling, including increased public space, planting and green spaces, plus improved highway design, suggests additional security measures will be needed. With the plan currently at the Royal Institute of British Architects (RIBA) stage 3 (the spatial coordination phase), it was a good point to integrate protective security from the outset, applying a ‘district-wide’ approach that is also responsive to the different scales.
This will allow the design team to plan for safety measures that are proportionate and responsive to the unique conditions, building on existing arrangements.
Collaboration across boundaries
Effective district-wide HVM will likely require buy-in from a wide range of stakeholders. In Knightsbridge, this meant the BID and its design team bringing together senior security personnel from flagship stores, hotels, cultural venues and other major sites, as well as property owners and asset managers. Officers from the Metropolitan Police, including Counter Terrorism Security Advisors (CTSAs), and representatives from local boroughs and Transport for London also contributed.
As part of the workshop, NPSA and Realm (landscape architects and authors of the design guide) provided an update on the current threat environment and key elements of the guide. Attendees were briefed on the Knightsbridge place strategy and its proposed changes for the district, as well as current HVM, before moving into geographically focused breakout groups.
Each group examined what should be protected, and how, within its given area, and identified targets and vulnerable places, wider threats, attitude to risk and potential interventions.
This collaborative approach generated several important considerations:
- Using the ‘every metre counts’ principle across a wider area creates greater opportunities for ‘softer’ HVM measures, such as landscape or layout changes.
- ‘Being a good neighbour’ matters. Tackling the threat to one area must not undermine the safety or functionality of another. A bollard line that protects one frontage may simply redirect risk to a neighbouring site with less protection.
- Balance is essential. We cannot protect everywhere. Collaborative dialogue provides a forum to make considered decisions about where protection is most needed and how residual risk should be managed.
- Documentation is critical. Recording how and why any decisions are reached – and maintaining that record over time – ensures that the rationale for protective measures remains understood as personnel change and circumstances evolve.
- Wider functionality must be considered. Deliveries, emergency access, and the general movement patterns and visitor experience all need to be factored into HVM planning.
The discussion illustrated the importance of integrating HVM thinking early in the design process for site, threshold and district approaches, especially as people who threaten our safety do not stop at red line boundaries. When acting to reduce threats from hostile actors, such early collaboration across a wider area should pay dividends: for safety and ease of movement, as well as maintaining operational effectiveness.
For those advising on public realm projects, the message is clear: engage early, think beyond the property boundaries, and build relationships with neighbouring stakeholders. In complex threat environments – and where ‘every metre counts’ – it pays to have good neighbours.
To access NPSA’s Public Realm Design Guide For Hostile Vehicle Mitigation please visit
www.npsa.gov.uk/specialised-guidance/hostile-vehicle-mitigation-hvm
Patricia Brown
Director at Central

