The window must have a net clear openable area of 5.7 square feet (5.0 square feet if ground floor), a minimum openable height of 24 inches, a minimum openable width of 20 inches, and the bottom of the opening must be within 44 inches of the floor.Size: The room must be at least 70 square feet, and no less than 7 feet in any horizontal dimension.Lighting & Ventilation: A natural light source (window) of not less than 8% of the floor area and natural ventilation (openable window/door) of at least 4% of the floor area are required.Heating: The bedroom must have heating capable of maintaining a minimum room temperature of 68°F.Smoke Detector: A smoke detector is required in each sleeping room.While a closet is expected in most bedrooms, the International Residential Code does not actually require a bedroom to have a closet.

If the tenants are staying usually the only initial repairs/renovations we do while they’re still in the unit is to upgrade the smokes/CO detectors to hard wired and anything else that turned up as a life-safety issue in the inspection.

Hard wired smoke detectors are usually required in remodel too.One caution on adding egress windows is they can become water traps.

The microscopic distance of the attic vent, insulation spacing, the smoke detectors not being in sync when 1 rings etc. 

Have you seen the detection devices that provide remote notification:  https://www.amazon.com/smart-water-leak-detector/s?

LeakSmart has leak detectors that you put on the floor around potential leak spots such as the washing machine or boiler.

Of this 20k is furniture/smart tech upgrades eg: $540 for 15 smoke detectors, $1650 for 15 blinds not bad but $1100 for a used fridge? 

Check the replacement date on the smoke detectors and the carbon monoxide detectors.Good Luck!

A failing roof or major basement/foundation issues yes - but not your usual missing smoke detector or leaky faucet. 

Also lots of small things filter & smoke detector batteries need changed, hardware is missing from one cabinet.