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Frequently Asked Questions About Building Science: Substantial Damage Estimator (SDE) Tool

Find answers to frequently asked questions regarding FEMA's Substantial Damage Estimator (SDE) tool, or see our other Building Science FAQ collections.

If you need additional information, please email the FEMA Building Science Helpline or call at 866-927-2104.

Substantial Damage Estimator Tool Guidance

Why do I need to determine Substantial Damage or Substantial Improvement for structures located in the Special Flood Hazard Area (SFHA)?

Communities that participate in the National Flood Insurance Program (NFIP) are required to determine whether damage of any origin meets the criteria for Substantial Damage when the damage is to a structure located in a mapped 100 year floodplain. Similarly, improvements to structures located in a mapped 100-year floodplain must be evaluated to determine whether the improvements meet the criteria for Substantial Improvement. Improvements may include rehabilitation, remodeling, and lateral or vertical additions. Check with the local jurisdiction on additional requirements for substantial damage and substantial improvement requirements.

What resources are available from FEMA regarding Substantial Damage and Substantial Improvement?

In addition to the SDE tool, the following FEMA tools are available:

Can the FEMA SDE Tool be used to evaluate both Substantial Damage and Substantial Improvement?

Yes. FEMA developed the SDE tool to help NFIP participants meet their obligation to evaluate damage or improvements before approving permits for rehabilitation, remodeling, and lateral or vertical additions. Although FEMA’s guidance on the SDE tool is geared toward estimating damages (as the name suggests), the tool can be used to evaluate improvements by substituting the cost of the improvements for the cost of repairs.

Am I required to use the SDE tool when determining whether damage is considered to be Substantial Damage?

No. NFIP participants may use other methods of determining Substantial Damage but are encouraged to use the SDE tool because it provides a formal, systematic approach for determining Substantial Damage while also meeting all NFIP requirements.

Alternative methods for evaluating Substantial Damage and Substantial Improvement are available in FEMA P-758 and FEMA 213.

  • FEMA P-758, Substantial Improvement/Substantial Damage Desk Reference (2010).
  • FEMA 213, Answers to Questions about Substantially Damaged Buildings (1991).

What is the current version of the SDE tool and the User Manual?

A5. The current version of the SDE Tool is SDE Version 3.0 (released August 2017). The current version of the FEMA Substantial Damage Estimator (SDE) User Manual and Field Workbook is FEMA P-784 (2017). It is available on the same website as the SDE tool.

Do I need administrative rights to install the SDE tool on my computer?

A6. Depending on the set-up of the user’s computer, administrative rights may be required for installation of the tool. The need for administrative rights is set by the agency, community, or other entity that is responsible for the security and maintenance of the user’s computer. The installation options and the need for administrative rights are available in the FEMA SDE Read Me - SDE 3.0 Tool Installation Guide and the FEMA Substantial Damage Estimator (SDE) User Manual and Field Workbook. Both documents are available on the same website.

What versions of Windows support the SDE tool?

The SDE tool can be installed on computers running Microsoft© operating systems Windows 7©, and Windows 8©, and Windows 10©. For more information, refer to Section 2 of the FEMA Substantial Damage Estimator (SDE) User Manual and Field Workbook.

Last updated September 17, 2020