>>212119793
You need to apply to the council to be granted warrant to purchase a key to unlock the device. This is not typically granted. Alternatively, you can put in a petition to have the opening limit raised. Twice yearly it's paud. 150mm is £150 if approved, £200 for 200mm, £250 for 250mm etc. The true annoying part is that it's per window.

T. Briton in the states