For all new construction, an energy calculation is required before your permit can be issued, to make sure your project meets the Florida Building Code – Energy Conservation. The building department reviews it during plan review.
The Florida Building Code requires all new construction and many remodeling projects to demonstrate compliance with the state’s energy conservation standards. Two of the most common compliance paths are R402 (prescriptive method) and R405 (performance method).
These calculations make sure a building meets minimum efficiency requirements for insulation, windows, HVAC systems, and overall energy use.
At Calc Wizards, we provide professional R402 and R405 documentation that satisfies permit requirements and gives contractors, architects, and homeowners confidence that their project is both compliant and energy-efficient. We prepare energy calcs for projects throughout Florida, including Tampa, Orlando, Sarasota, and Jacksonville.
An R405 energy calculation analyzes a home’s energy efficiency by evaluating heat loss and heat gain across the building envelope, including walls, roof, windows, and doors. By understanding how each component performs, builders can find the best ways to improve a home’s energy efficiency and meet code. The results are documented in the Form R405 compliance report submitted with your permit.
R405 energy calculations give homeowners and builders a clear picture of a home’s energy performance.
Because R405 evaluates the whole home, builders can balance trade-offs between components, such as using higher-performance windows to offset other areas, instead of meeting every requirement individually.
That information helps them design and build homes that prioritize energy efficiency, leading to long-term savings on energy bills.
R405 energy calculations are prepared using specialized software designed to evaluate a building’s energy efficiency. The software models the proposed home’s estimated annual energy use against a code reference design, considering the building’s dimensions, orientation, insulation materials, and the thermal characteristics of each component.
Once these factors are assessed, a detailed report is generated. The report helps builders pinpoint where energy efficiency can be improved, such as upgrading windows to more efficient models or adding insulation in walls and roofs.
Your R405 package can include Manual J load calculations, Manual S equipment selection, and Manual D duct design, along with the envelope leakage page for blower door testing and a duct leakage testing form if required.
The R402 prescriptive method outlines specific building requirements—such as insulation R-values, window U-factors, and SHGC ratings—that must be met exactly as written. It’s straightforward but leaves little room for flexibility.
The R405 performance method allows for more design freedom by using energy modeling to demonstrate that the building’s overall efficiency meets or exceeds code. This approach is often used for custom homes, additions, or projects where the prescriptive path is too limiting.
Both paths must still meet the code’s mandatory requirements, such as envelope air sealing and duct leakage limits.
Our team helps you choose the best path for your project and delivers the calculations needed for fast code approval.
Energy efficiency is more than a code requirement. It directly affects comfort, operating costs, and resale value.
Non-compliance with the Florida Energy Code can delay permits, increase construction costs, or result in failed inspections. By securing accurate R402 or R405 calculations upfront, contractors and builders avoid costly revisions and keep project timelines on track.
For homeowners, compliance means lower energy bills and a healthier, more comfortable indoor environment.
Calc Wizards is led by owner Mike Smith, a licensed HVAC technician with more than 25 years of experience, and has completed over 1,000 projects. We deliver reliable, permit-ready R402 and R405 reports.
Our process is simple: send your plans, provide basic project details, and receive clear, accurate calculations that pass inspection the first time. We provide next-day energy calculations for contractors, architects, and HVAC companies.
We work closely with contractors, architects, and energy raters to ensure compliance without slowing down construction. When your project demands precision and speed, Calc Wizards provides the energy code documentation that keeps you on schedule.
