I prefer copper for water lines and PVC for drain lines.
¼ turn shut off valves at toilets and under sinks are a great improvement.
Sink and toilet plumbing should be checked regularly for leaks.
Hot water heaters should be replaced after about 10-14 years depending on your water
quality. Water heaters tend to build up lime and calcium deposits that reduce the
efficiency. Several gallons of water should be flushed from a water heater once or twice
a year to remove some of this sediment.