Owning rental properties can be a lucrative undertaking. With the right preparation, pricing, and tenants, you can get a high ROI. However, units need a certain amount of upkeep, particularly between tenants. Whether you’ve just purchased your first rental property or you’re upgrading an old unit before a new tenant moves in, here are the five things you should replace or update.

1. Make sure the security lighting is working

It’s the landlord’s responsibility to keep functioning bulbs in common areas, such as the parking lot or building’s hallways. Choose long-lasting bulbs so that you don’t have to replace them frequently; they can last for anywhere from 9 to 18 years. If you also opt for energy-saving bulbs, you can cut down on your electricity bill. Checking the bulbs regularly will also limit how many calls you get from tenants that a bulb is out. Consider marking down on your calendar when you expect to replace a bulb so that you can have it done before the bulb burns out completely. It’s also a good idea to replace the lightbulbs in a unit before a new tenant moves in. While it may be their responsibility to replace the bulbs when they burn out, your tenants may get annoyed if their main overhead light starts flickering within one week of moving in.

2. Keep smoke alarms and fire extinguishers up to code

In between tenants, it’s a good idea to replace the fire extinguishers and install new smoke alarms. Once replaced, you won’t have to have to do it again for several years, so long as they’re not tampered with in the meantime. If you opt for smoke alarms that are battery-operated, you may need to replace the battery at least every year. While your tenants may replace the batteries for the smoke alarms in their apartment, you’ll at least need to keep an eye on the smoke alarms in common areas.

3. Invest in safer electric outlets

While they’re a bit more costly than regular outlets, GFCI outlets will automatically turn off if the electricity is running through something like water. These types of outlets are an excellent safety upgrade for your units. Sometimes, the law even requires that you use GFCI units in areas like the kitchen, laundry room or bathroom because these rooms have water units in them. Even if the law in your state doesn’t require this, it’s a good idea to use these types of outlets in the rooms that also have water units. To be extra safe, you could also replace every outlet with a GFCI outlet.

4. Upgrade the toilet to save your water bill

The toilet is one of the most important things you need to continually upgrade in a rental unit. By leaving an old toilet in a unit, you’re losing a ton of money. Toilets that leak can seriously increase your water bill – while your tenant may pay for heating and hot water, you’re likely paying the actual water bill, which includes everything that’s leaking out of that old toilet. Plus, some leaks aren’t noticeable, so it’s important to regularly check how well the toilet is functioning. Leaking toilets are more of a problem than leaky showers or faucets because the toilet can run all day long, which results in a lot of lost water. Note that you may be able to replace the interior toilet system and leave the toilet itself intact. The system includes things like the fill valve and flapper.

5. Change the locks with each new tenant

A lot of landlords don’t bother changing the locks between tenants because the locks themselves are still completely functional – some may even be nearly new. However, even if a tenant returned their keys when they moved out, you can’t be 100% sure they didn’t keep a spare or that they didn’t have a key copied. It’s not safe for your properties or your new tenants to live somewhere where others may have access to the building or units. Luckily, if you own several properties you can recycle the locks by swapping them out with locks from another building. Just make sure to keep track of which locks were used on which buildings so you don’t repeat them over time.

It can be tempting to just rent an apartment as is, especially if you only recently purchased the property. It can cost a lot of money to make renovations! However, if you want to keep your best tenants in their home or attract new ones when a unit is available, you need to have a good reputation for keeping your rental properties in tip-top shape. Also, while you may expect your tenants to take care of certain details themselves, like replacing the bulbs and smoke alarm batteries, offering to handle these simple upgrades will also give you an opportunity to enter a unit and see how the tenant is maintaining it themselves.