There are a wide range of innovative building practices that people have used in order to maximize how effective a single plot of land can be once all has been said and is now out of the way. There is no greater representation of the intelligence that people apply in this regard than that of major cities. The reason behind this is that these cities are vast and glorious, and a rather common trend within them is that buildings are usually built to be as tall as possible.
On the off chance that you are wondering why this happens to be the prime way of doing things in a city like Lake Forest, Illinois, suffice it to say that vertical construction tends to make buildings cost a bit less than might have been the case otherwise. This is a notion that you would do well to remember when the time comes for you to build your own home. Building up instead of building out generally refers to the vertical method of creating structures for people to live in, and it is usually a lot cheaper precisely because you can significantly increase living space without having to buy any further plots of land.
The biggest cost in any house is the land that it is built on, so if you want to maximize its value you should build up. That would enable you to house more people on that land which would have otherwise been very wasteful if only a single family were living on it. There is a limit to how high you can make your building, but approaching that limit is a useful technique.