Sunrise at the beach is mesmerizing. The Atlantic Ocean reflects in hues of green, blue and purple. A salty breeze refreshes the air.

The dream to have breakfast on the porch while enjoying a beach view makes it attractive to purchase a vacation home on one of Georgia’s barrier islands, or in the Carolinas.

Barrier islands come with problems to housing that one needs to be aware of before making the decision. In essence, they are dunes, piled up by the wind some 18,000 years ago when ocean levels were low.

Because they consist of almost nothing but loose sand, they shift around all the time. Inlets, which limit a barrier island on both ends, have a tendency to migrate. On the seaward side, the constant wave action moves the beach sand around.

Waves tend to hit the shore at an angle that’s controlled by the wind. But when the water runs off the sand again, it follows a straight, perpendicular path. In this fashion, the sand gets displaced by every wave.

On undeveloped islands, storm waves tend to wash across large areas and spread the sediment, which keeps the beachfront large. Buildings at the beachfront stop the overwash process, and the beach erodes. Left unchecked, such erosion makes the beach steep and narrow within a few weeks.

The reason we have sandy beaches on islands like St. Simons or Folly Beach, S.C., is replenishment by the U.S. Army Corps of Engineers. This outfit pumps sand from the Intracoastal Waterway onto beachfronts several times a year. Without that, there would be no beaches left on developed islands.

Hurricanes reach our Atlantic Coast almost every year. North Carolina is especially vulnerable because the state has a corner shape, reaching far out into the ocean. In Georgia, you can see attempts to stabilize the waterfront with seawalls, or with revetments that consist of stones placed on the sand.

Such hardened structures are not allowed in North Carolina because they cause more erosion of the sand. After a few storms, only lines of stones are left.

The onslaught of storm waves during all four seasons makes it advisable to regard a beach house as a temporary structure. If you can afford to see the ocean take it away after a time, the dream of waking up to a beachfront sunrise is within reach.