If you have some real value to protect better use professional solution. In other cases you need to rise a security level home made security system may do well enough.
So here it is – a PIC16F877A microcontroller based Alarm device which has quite some features including ability to dial phone number with DTMF generator, couple sensor interfaces with selectable sensitivity, up to 5W audio alarm output, RS232 interface. Additionally to this there is a light sensor which enables switching light depending on ambient light. PCB is one sided with through hole components – shouldn’t be hart to build one. Last job is to wire the house – there is also a laser barrier option present.