Can I make improvements to my existing home in the flood plain?

Yes, as long as the Flood Hazard Protection Ordinance criteria are met.  Improvements to an existing structure can be classified as either a Non-Substantial Improvement or a Substantial Improvement.  A Substantial Improvement to an existing structure will require that the entire structure be brought into compliance with the Village’s Flood Hazard Protection Ordinance, whereby the lowest level of the structure and all attendant utilities must be elevated to the Flood Protection Elevation (FPE), which is 2’ above the Base Flood Elevation (BFE).  These requirements are summarized, as follows:

For any improvements to the home (including an attached garage), to be considered a Non-Substantial Improvement, the total cost of the improvements must be less than 50% of the current market value of the structure, excluding the land, and must be calculated cumulatively over the remaining life of the structure, beginning with any permit issued on or after May 2014. 

If additions to an existing structure increases the building’s footprint by more than 20%, the addition must be elevated to the FPE. This increase in footprint is cumulated in aggregate, beginning with any permit issued on or after May 2019.  

To determine the current market value, you can either use the Cook County’s Assessor’s information, or get a certified appraisal, using the depreciated value of the structure.  The Village cannot take the replacement value of the structure, as it does not accurately reflect the market value.  

Cook County’s Assessor’s website can be found here.  You can search by address or property PIN.  To obtain the adjusted assessed value for the structure, take the assessed value for the structure and multiply by 10.  Then, to determine the substantial improvement value threshold, divide that number by 2.

Once the 50% cost of improvement threshold has been met or exceeded, it is considered a substantial improvement, and as noted above, the entire home and attendant utilities need to be elevated such that the lowest floor is at or above the Flood Protection Elevation (BFE + 2’).  This would most likely mean that you would need to fill in the basement and potentially jack up the rest of the home.  As part of the permitting submittal, copies of the executed contracts that outline the entire scope of work, and any subcontracts that may be necessary, must be submitted for review.

Show All Answers

1. What is the 100-year flood plain?
2. What regulations must be followed for construction within and adjacent to the flood plain?
3. What is the Base Flood Elevation (BFE)?
4. What is the Flood Protection Elevation (FPE)?
5. When is my house considered in the flood plain?
6. My property was never in the flood plain before, why is it in the flood plain now?
7. When do I need to buy flood insurance?
8. Can I build in the flood plain?
9. Are there any restrictions for construction for homes adjacent to the 100-year flood plain?
10. What are the criteria for being able to construct a new home with a basement in the 100-year flood plain?
11. Can I make improvements to my existing home in the flood plain?
12. What is compensatory storage?
13. How can I find out if my property is located within the flood plain?