Basement finishing in Arlington Heights, IL

The village amended the residential code on basement height. Parts of a basement that are not habitable space or hallway need 7 feet 2 inches from the top of the slab to the underside of the joists, and finishes may not take that below 7 feet.

For converting an existing basement to living space, the village lets the Building Official approve a lower ceiling where other safety features make up for it, but never below 6 feet 7 inches. With a drop ceiling, height is measured to the bottom of the grid. Ductwork and beams in a 1960s basement often sit lower than that, so we measure before we design anything.

A bedroom in the basement needs an escape window, and in Arlington Heights the window well must have a cover that lets light through, stops a 4 inch sphere and is rated for at least 250 pounds. Any bars or grilles must open from inside without a key or tool.

Zoning also limits the well itself. A window well may project no more than 4 feet from the foundation and must stay at least 3 feet from the property line. On the narrow side yards of many post war lots, that decides which wall the egress window goes on.

The post war boom gave Arlington Heights a lot of split levels and trilevels, and many have a crawl space under part of the house rather than a full basement. The village has a dedicated Crawl Space Conversion permit. It needs scaled plans, a contractor proposal and the construction fence and silt fence acknowledgment, since digging out usually means ground disturbance.

One zoning point to check on a raised lower level: basement space counts toward the floor area limit when more than half of its height is above the curb level or finished grade. That can matter if the house is already near its limit.

Part of the village drains through combined sewers, and the village says basement backups come in through the house sewer line when those mains fill. Its flood studies were prompted by the July 23, 2011 storm. Before drywall goes up, look at the Sewer Back up Rebate Program for an overhead sewer or an approved alternate flood control system. It does not cover overland flooding.

If the walls seep, the village has a separate Interior Drain Tile permit. It needs a floor plan showing the trench length, depth and width, and how it will be backfilled and covered.

We register before we pull, file the permit through the Civic Access portal, and schedule the inspections the village requires while work is in progress.