NorthernNewbie

Hi, First post so please be nice. Doing a house refurb and had new escape windows put in but the BI has told me I'll need to pop a guard on. Has anyone had any experience of this? What sort of guard should I look at and where from? I noticed someone had mentioned popping a unlockable catch on the window but I'm not sure that would pass. Struggling to find a guarding solution. Any help welcome. Thanks in advance.