Home addition — Single-story addition Cost in Chicago, 2026

Why single-story addition × Chicago produces this band

A single-story addition scope for a home addition in Chicago combines two price levers: scope and metro labor rates. Single-story additions extend the existing footprint at grade — new foundation section, roof tie-in, and framing that matches the existing structure. No structural work on the original house beyond the tie-in. Against the national median remodel labor rate, Chicago runs 15% above the national median — so the single-story addition band comes in at the mid-range, then scales 15% above the national median on top of that. Permit timelines for residential work in Chicago typically run 6-14 weeks, which is the window you plan your design and decision sequence against. This page gives you the actual 2026 Chicago bands for this exact combination, plus the three cost drivers Baily asks about first when scoping the project live.

What drives cost for a single-story addition scope

• ·Foundation extension (slab or stem-wall to match existing)
• ·Roof tie-in flashing and structural connection
• ·Exterior siding match (often requires whole-elevation repaint)
• ·HVAC extension into the new zone

What makes Chicago different

• Labor — Union trades (carpentry, electrical, plumbing) are the majority of licensed remodel labor — premium over national median.
• Labor — Winter shuts down most exterior trades Dec-Feb, compressing schedules into a 9-month season.
• Labor — Chicago Prevailing Wage Ordinance drives labor costs on any publicly-touching work.
• Material — Midwest steel and framing lumber are priced competitively vs coasts.
• Material — Masonry restoration (common in pre-war Chicago brick) uses specialty materials with long lead times.

Chicago rules that affect this scope

• Chicago DOB self-certification is available for registered architects — compresses permit timelines.
• Landmark districts (e.g. Lincoln Park, Old Town Triangle) require Commission on Chicago Landmarks review in addition to DOB permit.
• Chicago Energy Conservation Code (IECC 2021) applies to all work changing envelope or HVAC.
• Two-flat and greystone conversions frequently trigger zoning variance — timeline extension of 8-14 weeks.

Scope your home addition with Baily.

Baily asks the eight questions that determine where your project lands inside the $161K-$368K band for Chicago and hands the scoped brief to one licensed builder.

Related pages

Questions LA homeowners actually ask

• What is the 2026 cost range for a single-story addition scope home addition in Chicago?

  $161,000-$368,000, with the median landing near $264,500. The range reflects finish tier and layout complexity within the single-story addition scope; the Chicago labor multiplier of 1.15× vs national median is baked in.

• How long does a single-story addition scope home addition take in Chicago?

  18-26 weeks of on-site construction for the single-story addition scope, plus 6-14 weeks of permit review in Chicago if the scope requires a permit. Cosmetic-only refreshes often skip permits; anything touching plumbing, electrical, or structural does not.

• What is the single biggest budget-overrun risk for this scope?

  Matching old siding or brick — if the material is discontinued, the whole elevation has to be reclad. $8-20K unexpected if not scoped up front.