Humans used to live in caves. Then we discovered tools and started to build machines. Over time, building techniques and materials became more sophisticated. We’ve come a long way to say the least. But the view from now compared to even a few decades ago may surprise you when it comes to the form and function of our houses.

You may be wondering: how has the average U.S. home changed over time? A report from the U.S. Department of Housing and Urban Development- entitled 2015 Characteristics of New Housing-has some interesting insights.

Homes Getting Bigger

Next time you’re out for a stroll, look around at the houses you see. Is it just you, or are they bigger than they used to be? The good news is you’re not imagining things. Housing size is statistically on the rise. The average size of a newly build U.S. house reached 2,687 square feet in 2015 (the highest figure ever). That’s an increase of over 1,000 feet over the average size from 1973, which was 1,660 square feet. This jump represents a whopping 62 percent increase in just 42 years.

As housing size swells, the average number of household inhabitants shrinks. Back in 1973, each home housed an average of 3.01 persons per dwelling. Now it’s down to a new low: 2.54 persons per household. This means there’s simply more living space per person than ever before by almost two times!

Rising Homeownership Costs

Another insight from the report, as noted by the American Enterprise Institute, is that the price per square foot of housing (once adjusted for inflation) has actually stayed somewhat stable throughout the last 42 years-generally in the range of $107 to $128 per square foot. But of course, this only represents construction costs.

In general, a larger home means more upkeep and higher associated maintenance costs. A quick rule of thumb is to set aside approximately one percent of your home’s purchase price per year for maintenance. Thus, a bigger home with a higher square footage count will inflate physical and financial responsibilities for upkeep. A homeowners insurance quotes comparison will likely reveal that, while shopping around can certainly help you save, monthly premiums tend to be higher for larger spaces because there’s more to protect in case of a claim.

Making the Most of Extra Space

Where is some of this extra space coming from? The report indicates that storage spaces (like closets and garages) have become more of a priority over time. As one building developer in New York City mentions to the New York Times, “Frankly, with every building we do, the closet space is larger than the last building we did.” It looks like “walk-in master closet” is much more than just a buzzword you hear on home design-based television shows.

There’s also more attention on features formerly thought of as “luxuries,” like air conditioning units. Today, over 80 percent of U.S. homes feature some kind of air conditioning system; by comparison, fewer than half of homes built between 1973 and 1976 did.

Sometimes change happens so gradually around us that it’s hard to pinpoint exactly what’s different-until the difference is night-and-day obvious. That’s how the average U.S. home has changed over time.

While homes have increased substantially in size over the past four decades or so, the number of people living in each one has decreased, leaving more space per person. There’s also been a widespread adoption of appliances once considered rare luxuries, like air conditioners. While these additions often boost comfort, they may necessitate higher expenditures when it comes to homeowners insurance premiums and maintenance costs.