With some parts of your home, it’s easy to see how you can stay in fashion. Some fresh new furniture and a nice coat of paint can transform a room, and although it costs more you can add both style and value to your home by remodeling your kitchen or bathroom. But why stop with the obvious rooms? You can also upgrade your home’s basic utilities like your water heater or your furnace, and while a new furnace won’t change your home’s look you can add some surprisingly fashionable upgrades.

1. Upgrade the Air Filter

Just about every central air system can get the job done because they all have to meet certain standards set by the local housing code. However, you can do a lot better than just the basics. You can do a lot for your indoor air quality by simply replacing the standard air filter with one that can trap smaller particles, or you can get one that uses static electricity to make sure airborne pollutants never pass through. You won’t even need to replace the furnace since many filter types can fit into the same slot.

2. Replace the Furnace with an Efficient Model

As technology marches forward, people are constantly coming up with new designs that can create more heat using less energy and move that heat through the home more effectively. At the same time, older furnaces tend to wear out and use more power to heat your home than they did when they were new. Today’s high-efficiency models aren’t just a way to stay in-fashion by keeping your carbon footprint small, they’re also a way to save money on electricity and natural gas in the long run. Your local heating and air company will have several options you can choose.

3. Consider Geothermal Energy

It’s an expensive upgrade, but you may want to heat your home using nothing but geothermal energy. Known as a ground-source or geothermal heat pump, these systems move air through pipes buried deep underground where the temperature is stable no matter how hot or cold it is on the surface. The HVAC system then delivers this air to your home, keeping it at that same stable, comfortable temperature no matter what the weather looks like. A geothermal system is expensive, but it can save you a lot of money if you plan on living in the same house for decades.

4. Change the Siding

The insulation in your home is part of its heating system. With bad siding, your furnace has to work extra hard to keep your home at the right temperature. Most of the insulation is inside the walls of your house, but you can also buy insulated siding, a housewrap, or add foam board insulation under the siding to trap more heat. This also gives you an excuse to change the look of your home’s exterior.

Style and substance don’t always have to be at odds. Sometimes upgrading your most practical systems can score you some real style points, even if you have to take your guests on a house tour so they can appreciate the changes