As winter comes around the bend, energy use will skyrocket. Long hot showers and hot baths will result in money down the drain. As landlords prepare for the cold weather, heating costs will be a central concern. Heating bills can total upwards of $130 per month in the winter for a standard two-bedroom apartment. If each apartment has a separate water meter, it could add another $50. Electricity costs could tack on another $100 and for a 500-unit building, that's a total of $150,000. As a landlord, this should concern you. Here are some ways to conserve energy during the winter months and protect your bottom line: Water: The Environmental Protection Agency (EPA) reports that American buildings use a combined 20 billion gallons of water a day for sinks and showers. Installing tamper-proof shower and sink regulators such as the Water Scrooge, saves up to 40% annually on water and energy costs: $1,000 on average per year, per apartment for water charges, $300 on average for heating the water and over a half million dollars for a 500 unit building. Set domestic hot water (DHW) systems no higher than 120 degrees for a 3-5% in annual savings. Heating/Cooling: Roof-top solar panels or small wind turbines can help landlords save. They use at least 10% less energy than standard models. Weatherizing: Controlling airflow is a vital part of energy conservation. Older apartment buildings with poor seals, ill-fitting windows, improperly sealed ductwork and even small gaps around electrical outlets can result in air leaks. Caulking can seal gaps. Something as simple as a draft-catcher placed under a door or along the base of a leaky window can help control airflow. Appliances: Replace old, energy-guzzling appliances with Energy-Star rated ones, which are 50% more efficient. Invest in a separate heating and cooling system for the building's laundry room. Fortify the dryers with a circuit sensor system that allows them to operate at lower volume when they are not in use. Reinforce common areas with sensors so that the lights are only on when the area is occupied. An open dialogue with tenants will keep down energy costs. David Schwartz is the inventor of The Water Scrooge and CEO of DS Magic Tech, LLC, Lynnbrook, N.Y.