The village is most known for its rampant residential growth which occurred most heavily in the 1990s. Once a sleepy lakeside village of cottages and small ranches, its population skyrocketed as developers flocked to the area in the 1990s. Its population increased by 17,000 people (a nearly 400% increase) over this period, making it one of the most rapidly growing suburbs of Chicago and in the United States at that time. At the height of its building boom, the village issued over 1,000 residential building permits in 1995.
In the late 1990s, the village faced the challenge of providing adequate services and infrastructure as well as establishing an identity and community unity, since many community services (Libraries, Schools, Fire Districts) were pre-delegated to neighboring communities like Huntley, Algonquin and Crystal Lake. However, the village continues to expand its resources and community offerings and is also endeavoring to diversify its tax base and provide more commercial and industrial businesses.
Lake in the Hills Airport, convenient shopping and entertainment along Randall Road, low crime, well-kept neighborhoods, abundant community activities, and an excellent parks system helps the village continue to maintain an excellent reputation and a place that people want to continue to live in or visit.
As of the census of 2000, there were 23,152 people, 7,652 households, and 6,297 families residing in the village. The population density was 2,461.9 people per square mile (951.0/km²). There were 7,866 housing units at an average density of 836.5/sq mi (323.1/km²). The racial makeup of the village was 91.59% White, 1.50% African American, 0.14% Native American, 3.33% Asian, 0.02% Pacific Islander, 1.86% from other races, and 1.56% from two or more races. Hispanic or Latino of any race were 6.31% of the population.
There were 7,652 households out of which 51.8% had children under the age of 18 living with them, 73.4% were married couples living together, 6.2% had a female householder with no husband present, and 17.7% were non-families. 13.0% of all households were made up of individuals and 1.8% had someone living alone who was 65 years of age or older. The average household size was 3.03 and the average family size was 3.35.
In the village the population was spread out with 33.4% under the age of 18, 5.4% from 18 to 24, 44.5% from 25 to 44, 13.4% from 45 to 64, and 3.3% who were 65 years of age or older. The median age was 31 years. For every 100 females there were 100.7 males. For every 100 females age 18 and over, there were 98.8 males.
The median income for a household in the village was $73,313, and the median income for a family was $76,921 (these figures had risen to $80,992 and $84,761 respectively as of a 2007 estimate). Males had a median income of $51,598 versus $34,449 for females. The per capita income for the village was $26,239. About 1.6% of families and 2.1% of the population were below the poverty line, including 2.3% of those under age 18 and 0.9% of those age 65 or over.