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Ohio 2024 IECC cost-effectiveness tool

This guide explains the Ohio 2024 IECC cost-effectiveness tool for the people who use it: energy raters, reviewers, and EEHM staff.

What the tool does

The tool compares two versions of a home:

  • A baseline model built to the 2019 Ohio Residential Code.
  • One or more proposed models that add 2024 IECC efficiency improvements.

It then answers one question: over a 30-year period, do the energy savings from the proposed improvements outweigh their added cost? It produces the numbers an Ohio code-compliance reviewer needs to make that call.

The three methodologies

The tool combines three established methods:

  • R408 credit selection — Ohio's additional efficiency credit pathway. You choose the compliance pathway whose credit target applies, pick the efficiency measures the proposed home uses, and confirm it earns enough credits to comply in both Climate Zone 4 and Climate Zone 5.
  • PNNL lifecycle cost (LCC) — a 30-year net-present-value calculation based on the U.S. Department of Energy / Pacific Northwest National Laboratory method. It turns energy savings and up-front costs into a single dollar figure.
  • Cost Bridge Table — a structured way to price the proposed improvements, matching the equipment in each model against a reviewed cost catalog.

Baseline versus proposed

Every comparison has exactly one baseline model and up to six proposed models. The baseline represents the code-minimum home. Each proposed model represents one packaged set of improvements you want to evaluate. The tool always measures savings and cost as the difference between a proposed model and the baseline.

Who it is for

  • EEHM staff create analyses, load models, and manage who can see them. Staff can edit every part of the tool.
  • External reviewers (energy raters and code reviewers) are granted access to a specific analysis. They can work through the R408 and lifecycle-cost tabs, and — when staff enable it for them — the Cost Bridge Table.

See Getting started for how access and sign-in work.

The five tabs at a glance

Beyond the Overview summary tab, the tool is organized as five working tabs you move through in order:

  1. Model Library — load the baseline and proposed models from Ekotrope. See Manage models.
  2. Code Comparison — a reference table contrasting the 2019 Ohio code with the 2024 IECC.
  3. R408 Credits — choose the proposed home's efficiency measures and confirm credit compliance. See Select R408 credits.
  4. LCC Engine — enter costs and run the 30-year lifecycle cost calculation, including the Cost Bridge Table. See Enter LCC inputs and Use the Cost Bridge Table.
  5. Results — review the combined results and print a one-page PDF deliverable. See Read results and print the PDF.

New terms used throughout this guide are defined in the Glossary.