Check your attic if your placing cameras under the eaves. I found perpendicular 2x6s, long edge up, capping the sills at the edge of the roof. We can have Tornados here, so the 2x6s reinforce the roof junction.
Right angle drill head, parachute cord, and fiberglass flexible pole resulted in adding 80 USD to the mission as my flabby body cannot get in tight to the shallow pitched roof, and the roofing nails hurt your back and neck. So I drilled the 2x6s and probed from the outside to find my passageway. That was a PITA.
Summer heat, crawling in an attic with no floors, small hatches, wasps, lack of suitable assistant, and fiberglass insulation itch can be factors. Pulling POE in a modern house really wasn't a problem. The last half meter was the problem.
Expect to need spray foam or RTV if things can get wet, the cameras generally come with seals for the POE junction to the short jumper extending from the camera.
In my case the POE can rub on sheet metal, so split loom tubing went around the POE at the sill and through the eave. Probably overkill, but good practice.
Hopefully 1 TB SSD is in my future, but "spinning rust" was far cheaper at the time.
Good cameras come with template stickers. However the Amcrest self tapping screws were not for sheet steel, I replaced the screws with #6 self tapping sheet metal screws, stainless steel.
In three years of operation in farmland, I have cleaned the domes twice, and repositioned the ccd board inside a dome once on a camera on the windward side. Outdoor side is low maintenance.
We have serious winters here, but the internal heat from the IR leds and camera core has been sufficient to deter fogging and icing.
Amcrest's Camera AGC drives the IR Leds and receives an evaluation of "Awesome".
Creepy neighbor used his cell phone camera, according to another neighbor, to map the IR pattern. My upper cameras are aimed somewhat parallel to the house walls, so there are no sneak paths, but have plenty of angle left to cover out in the yard and 20 meters to the local road. The cameras are adjusted not to see in my windows, but do view the house walls and windows.
Something to think about if using OEM /experimenter grade camera is the day/night transition.
My cameras have a RCA plug with bias for an electret mic and a contact closure input for a standard NC sensor. The DVR supports audio over Ethernet from the camera, the contact closures, and scheduling for each camera if needed. Also have SD card for stand alone.
My neighbor was harassing , teasing and perhaps extorting my late, elderly Mom. Key word " Was".
Net cost 700 USD, spread out over time. Plenum POE cable that meets fire regs for the attic was a major cost. That does not include the LCD monitor. I caught a closeout sale for the cameras.
The Homeowners Insurance offers a discount for fire alarms, Co2 alarms, and security systems. Not much, but it will offset some of the cost per year.
RFI on the over the air TV nixed using un-shielded Ethernet cable for two attic runs. Our TV antenna is a massive YAGI inside the attic roof with a parallel run of 300 Ohm Twinlead to the pre-amp. I suspect the actual emitted RFI is very low.
Make sure you can export the video in a common format with stills.
Cloud Option added 19.95. a month for very limited storage. Decided it was cheaper long term to store on site.
Steve