Chicago housing stock is old, and it lies to you.

What goes wrong, by building type

Greystone, 1890-1915

The limestone facade is soft and it was laid in lime mortar. Almost every greystone in the city has been repointed in cement at some point since 1970, and cement traps water behind the stone until the bed joints fail. We find it on three elevations more often than one. Repointing in matched lime is slower, dearer per square metre and the only version that does not have to be done again in fifteen years.

Brick two-flat, 1900-1930

Knob-and-tube wiring behind the kitchen wall, a cast-iron stack with two decades of life left in it, and joists that were never sized for a stone counter. The kitchen you want is usually possible. Whether it costs $70,000 or $130,000 is decided by where the waste line already runs, which takes twenty minutes to establish and nobody does.

Bungalow, 1915-1935

Rear walls rot at the sill plate because a gutter failed in the 1990s and nobody looked. Attic conversions run into the same two constraints every time: clear headroom over the required area, and a second means of escape. Both are measurable in an hour.

Mid-century ranch, 1950-1970

Uninsulated cavities, a rim joist leaking heat all winter, and a panel with no capacity for induction, a heat pump and a car charger at the same time. A heat pump quoted for one of these houses without a borescope in three cavities is a machine sized against a hole.