Obscuration is a technique used to prevent hostile surveillance into a well-lit building at all times, whilst minimising the obstruction to outward visibility, without the need to block windows, fit opaque shutters or install blinds.
When obscuration is used
Whilst generally applied to windows it may also be used at entrances where there is controlled access, such as via tube stiles for personnel security. The options available for obscuring vision include:
- Reflective and screen printed films - retrofit options
- Tinted or electrically controlled glass - original fitment
- Etched glass - original fitment (prevents outward vision)
In partnership with SSG, NPSA has produced general advice on good practice relating to obscuration technologies, in particular window films. The guidance note provides more details on the measures that could be used.