Real estate has changed dramatically in the past 40-50 years. Land costs have driven the price of land up 10 fold over the past 20 years. Illinois builders and land developers often buy land when it is available to lock in costs and hold tracks of acreage for decades until the zoning or market is right to subdivide and develop. This practice is only possible for large builders and developers which may account for the dominance of a few large local or national builders.
Higher land costs mean higher construction costs when the cost of the lot is factored into the cost of a home. Homes have risen in price along with the rise in land/lot costs. Ramblers, which were very popular during the 1950s and 1960s are no longer cost effective for large developments. The "footprint" of the Rambler, or Rancher, is too large for the average lot size in developments within Illinois. New Ramblers / Rancher Style homes are usually custom built and quite expensive on a cost per square foot basis.
See the models below which represent most home styles found in the Illinois real estate market.

The Colonial
Cost effective for small footprint and low utility costs for heat and cool. The average home built in the past 20 years in the Illinois real estate market will be a two story home with 4 bedrooms on the upper level, 2-3 full baths, depending on the square feet, a library for homes offering more than 3,000 square feet; foyer, living room, dining room, kitchen, breakfast area on the main level; finished or unfinished basement. Two car garages are the most in demand and three car garages or garages with a side load are popular on lots of 1/2 acre or more.

The Rambler(Ranch)
The Rambler is the classic one level home that has been constructed in Illinois in all communities for over 100 years. Recently, with the rising cost of land, fewer Ramblers have been constructed, making the resale market very attractive for these homes. The Rambler or Rancher is a one level home that may have a Ramblers are popular with families with young children who don't want steps to temp young children to go up or down. They are also popular with older home owners who don't want to have to climb steps daily in their living areas. Ramblers also take larger lots than the Colonial because of the large foot print and the cost per square foot is higher than the Colonial due to the larger foundation costs ( if the house has a basement) and the higher roofing costs.

Split Foyer
Enter the front door onto the foyer level and there will be steps, usually 5-6 steps going up to the upper level and 5-6 steps leading to the lower level, which may or may not be finished. Popular with builders due to the low construction costs because the homes are built on a slab. The Split Foyer offers an upper level that generally contains 3 bedrooms 2 full baths, living room, dining room and kitchen. Lower level recreation rooms, additional baths, another bedroom and an integrated garage is also possible. Many Split Foyers have attached garages.

Split Level
Rarely built today, but many resale Split Level homes are found throughout the area.

The Cape Cod
Popular throughout the area in the 1940s - 1960s. Usually constructed with unfinished upper level which could be "improved" as families grew.

The Townhouse
Wonderful starter homes for first time home buyers. Cost effective and offer more living space than expected.