What matters for project planning
Climate is the real subject here rather than the stormwater ordinance. Northern Illinois asks a system to cover a genuinely wide range — deep winter design temperatures at one end and humid summers at the other — which makes the heat-pump balance point a real engineering question rather than a marketing one, and makes latent capacity matter as much as sensible capacity in July. The one place the city's framework touches this trade is condensate: a cooling system produces water, and a line discharging beside the foundation creates exactly the moisture problem the on-site stormwater control requirement exists to prevent.
Official sources
Verify the property, not just the city
Citywide context cannot establish a parcel’s flood zone, historic designation, stream buffer, permit requirements, soil conditions, or concealed construction. Confirm those items with the appropriate authority and selected provider before work begins.
Sources reviewed 2026-07-26. External requirements and maps can change.