Deciding to get a storage unit is often something people do because they have no choice, like their house isn’t finished and all their stuff won’t fit into their temporary apartment. Or, the lease on one apartment ends a week before the new one starts.

For those storage customers, the question of if or when they should rent a storage unit is an easy answer: Yes and now.

But what if you aren’t sure if you need or want a storage unit. How do you decide if you should do it and when you should do it?

Our general advice for people is to think about the things you are going to store and why you are considering storing them. For some things, it’s an easy answer; for others, you might want to break out the calculator.

Storage units are not a huge expense, but they aren’t cheap either. And almost every money manager in the country will tell you that they are a way to instantly save on your budget. Yet just shy of 10 percent of Americans have at least one and it is the fastest growing form of commercial real estate and has been for years.

So why do so many people discount sage financial advice?

Because we as humans like to hold on to things that are special to us. When we lose a parent, or grandparent, or sibling, we want to hold on to some of their things to remember them by. For example, when my grandmother died last summer, there were a few family mementos that I wanted to keep. They completely don’t match the decor of my home and I didn’t have extra space to keep them, but I wanted to keep them and make sure they stay in the family. I’ll hand them down to a niece or nephew one day.

If I do the math, are those small pieces of furniture what I am paying to store them? Probably not, but you can’t put a price on memories.

When you suffer the loss of a loved one and can’t imagine parting with their things, putting stuff in storage until you are past your initial grief and ready to make a decision is good for your mental health.

On the other hand, if you just graduated from college and have your college apartment furniture stuck in a storage unit, you might be wasting money. Once you start a career, college furniture is not likely to be something you want to keep. And, as a new graduate, you probably want to save every dime you can. Sell your college furniture to other students and save yourself some money.

What about those times when you have too much stuff for your space?

Then it’s time to take a good look at how soon you’ll be getting a larger space, how much the stuff is worth and if it has irreplaceable sentimental value.

When you get a storage unit is usually determined by when the stuff crowding your house gets to be too much, but if you are planning ahead, early spring is the best time to get a storage unit. If you wait until it’s been nice for two solid weeks, chances are your selection will be lower and the prices will be higher. If you are ahead of the crowd, you’ll get a better price, better selection and a head start on your spring cleaning.