Top 30 recommendations for SHTF security in the average brick house:
Spread preps around friends’ and families’ homes.
Build a mutual assistance group.
Build a surveillance network of neighbours, drones or cameras, etc.
Hide your preps and use of them.
Live where neighbours but not strangers can see you, and not too isolated or crime riddled, and avoid flats.
With small gardens and being open to the street, fences are of little use, but if you want a fence, add a topper and cover it with an alarm (driveway alarms, eg MyDome), cameras and lights (eg solar PIR, mains lights eg Swann, lightswitch timer, TV simulator).
Build concrete planters if ramming is a risk, eg TerrorBlock.
Rig up battery/solar powered cameras, alarm and lights, eg camo solar sim cams like Reolink or UWatch Cube. Mains powered systems will not last long after SHTF, but fit British Standard lighting, alarm and CCTV for use until then, just do not rely on it once electricity, phones and internet goes down.
If the hardened facade worries you that intruders can still come through the roof, spread the weight of reinforcement by lining the roof, loft and ceiling with 8-15mm plywood and exmesh, or Securilath, replace the loft hatch with a locking version and consider steel roof tiles eg Aerodek.
Treat an in-use garage door as a window in terms of adding a security roller shutter, as there is not much of a market for swinging security garage doors (the strongest of which is Teckentrup 62 to SR1 & RC2), otherwise screw it shut and board it up from behind.
Consider an active delay system such as FogBandit.