If you are subject to, or intend to change to, Time-Of-Use price schemes for electricity consumption, running the pool filter pump during off peak hours can save a substantial amount of money; since off-peak rates are significantly lower than on-peak rates.

Some stoves do not make efficient use of energy;

A leaky toilet can waste 20,000 gallons a year. Toilet leaks in many cases can be obvious (sounds coming from the toilet when it is not running), but in other cases can be harder to detect.

Just one faucet with a constant drip can leak up to 10,000 gallons a year.

Some water heaters lose much of the heat they consume. This is especially true of older and lower cost models, and important in homes with large numbers of people.

Electric water heaters are much more expensive to run than gas ones. This is especially true of older and lower cost models, and the running cost difference is much more significant in homes with large numbers of people.

Over time, the interior and exterior of buildings can have moisture problems (e.g. mold) which can severely erode the building structure and also lead to serious occupant health problems or building-related illnesses.

Older building can have materials that are potentially poisonous. When the materials and building structure degrade, it can lead to serious occupant health problems or building-related illnesses.

Glass doors can lose heat in the winter, and gain heat in the summer. This can be prevented by replacing them with multipaned and insulated frame glass doors.

A cool roof will significantly reduce the loss of coolness in the summer. This is especially important in areas where air conditioning is used a lot.