Complex subjects, such as housing, require thoughtful exploratory pieces to explain the intricacies of the issues. But we can gain a lot of insights – and perhaps a few chuckles – from tidbits of information.

Here are few related to real estate:

• The United States is about 2.5 million units short of its estimated future housing needs, based on long-term projections, according to Freddie Mac. In fact, the Urban Institute has found a shortfall of 350,000 units per year beginning in 2009, due to underbuilding.

Real estate costs, as in most transactional businesses, are based on the laws of supply and demand. Clearly supply is not keeping up with demand.

• Millennials (ages 23-38) have overtaken Baby Boomers as the largest generation of U.S. adults. And they are starting to buy homes.

In fact, Millennials currently account for more than one-third of U.S. homebuyers, with the Bay Area one of the five hottest housing markets for this age group.

• In Indiana, homeowners can spray lines of purple paint on trees or posts in front of their property instead of posting “no trespassing signs,” thanks to the Purple Paint Law enacted last year.

Signs get torn down and vandalized, and building a fence is expensive, so this is an inexpensive alternative. In Texas, that same paint indicates “no hunting allowed.”

• The rate of homeownership for African-Americans is falling, while homeownership rates among the Hispanic population are rising, according to census data.

Black homeownership has dropped 8.6 percentage points since its peak in 2004.

This divergence marks the first time in more than two decades that the two largest racial or ethnic minorities in the country are not on the same path in terms of to owning homes.

• Every school child knows the original White House was burned down by the British during the War of 1812. But did you know parts of the current building burned a little over a century later?

On Aug. 24, 1814, British soldiers led by Major Gen. Robert Ross burned down what was then known as the Presidential Mansion, as well as the Capitol and other government buildings, in retaliation for U.S. attacks in Canada.

Reconstruction began almost immediately and was completed in 1817.

In 1902, the gaslights were replaced with electric ones, the East Terrace was rebuilt, the State Dining Room enlarged, and a “temporary” executive office space that would become the West Wing was added.

In 1929, the interior of that West Wing was destroyed by fire.

Other additions and renovations were conducted over the years, but the most recent major changes occurred after World War II, when the entire building was completely gutted and its original wooden joists replaced with concrete and steel beams.

The project lasted three years, from 1949 to 1952.

• Both the lowest- and the highest-priced homes in the Valley are in Livermore.

There are currently 170 homes on the Multiple Listing Service in Livermore, 141 in Pleasanton, and 130 in Dublin – a high point for the year, as July is usually a slow time for home sales.

Those homes range in price from $349,900 to $7.9 million, with a median home price of $925,000. The most affordable home listed is a 1-bedroom, 1-bathroom condominium in Brookmeadow Park. At the top of the list is a 20-acre vineyard property with a 5,287-square-foot home on Kalthoff Common.

• For about the median price of a home in the Valley, you can purchase a genuine castle complete with turret on about 50 acres in Midi-Pyrenees in France.

The castle has 10 bedrooms, nine bathrooms, a pool and a wine cellar. A separate caretaker’s cottage has three bedrooms and one bath. It’s all fully furnished. Stunning views.

French property specialists are claiming there are now more castles on the market than ever before, with many being purchased by foreigners from places such as Australia, where their currency is strong against the euro.

• In Crossville, Tenn., a local minister labored 20 years to construct the world’s largest treehouse.

In 1993, according to the Rev. Horace Burgess, God told him, “If you build a tree house, I’ll see that you never run out of material.”

The result: a 100-foot-high structure of 10,000 square feet with multiple floors and dozens of hidden rooms and passageways built almost entirely with recycled materials. The roofing material is clear to let in natural light and illuminate the interior. One whole room is filled with dozens of hand-carved religious statues. The top floor features a 5,700-pound chime tower with bells made of oxygen acetylene bottles.

At the epicenter is a chapel.

The structure is supported by a massive 80-foot oak and several other smaller trees. A swing hangs from one of the highest points of the tree house, allowing visitors to swing a few feet above the ground.

It probably won’t surprise you to learn that the treehouse was not built to code, so the state fire marshal closed it to the public in 2012.

Burgess spent thousands of dollars making his dream a reality. No one lives in it, but before it was shut down, about 1,000 people visited this tourist stop each week.

• A home with a picket fence may be a traditional part of the American dream, but you can’t have it in Scranton, Penn.

City regulations outlaw “pointed fence pickets” there.

In Rhode Island, fences “unnecessarily higher than six feet” that are put up to annoy your neighbor are labeled “spite fences” and considered to be a private nuisance and thus forbidden by law.

For more information about houses, housing, fences or anything else to do with real estate, contact your local Realtor today.

Cher Wollard is a Realtor with Berkshire Hathaway HomeServices Drysdale Properties in Livermore.