Schools have a narrow window for installation and a wide range of signage needs, which is why buying it piecemeal across a year tends not to work. A single coordinated scheme surveyed in the summer term and installed over the holidays is both cheaper and less disruptive.
The usual scope covers the main entrance sign, visitor routing to reception, safeguarding and site notices, department and classroom signage, hall and corridor graphics, and any external boards for the field or car park.