How Are Title 24 Energy Calculations Done, Step by Step?
Approved software models your design, builds a reference house of the same size and climate zone from the prescriptive rules, and simulates both. The design passes when its energy use is no greater than the reference. The result is a certificate, the CF1R, signed by two people and checked by the building department.
- Choose your report
- Upload your plans
- Pay securely
- Permit-ready report by email
Step 1: the consultant collects data
Every component needs numbers. For the envelope that means the area of each window, wall, door, roof, ceiling and floor, with U-factor, SHGC, solar reflectance and thermal mass. For mechanical systems it means equipment type and efficiency, the water heater type and efficiency, how hot water is piped, and the size, slope and orientation of any solar array. Most of it comes from your plan set.
Step 2: the model is built
The basic data goes in first: floor area, number of stories, occupancy and climate zone. Next come the surfaces with orientation, area and thermal properties, plus fixed shading such as overhangs and side fins. Inputs must match the final approved plan set.
Step 3: both houses are simulated
The software writes the reference house itself. For a new building it uses the same floor area, volume and configuration as yours, with walls and windows spread evenly over the compass points. It then reports source energy, efficiency long-term system cost and total long-term system cost. For additions and alterations, compliance rests on the long-term system cost alone.
When the result is a fail
The arithmetic is not negotiated; the inputs are. The consultant changes the design, perhaps a better window, more insulation or different equipment, and runs it again until it passes.
What the software does not check
The software may not check mandatory measures automatically, so the consultant confirms them by hand.
What you receive
The principal output is the certificate of compliance, CF1R-PRF-01-E, with one section of special features and one listing items that need ECC field verification. The documentation author certifies it is accurate and complete, and the responsible designer certifies conformance with Part 6. When field verification applies, it is registered with an ECC-Provider before it goes to the building department. Read how to read a CF1R for the layout, or the calculations overview for what we need from you. The software behind it is explained in what CBECC is, and you can order a residential report directly.
Common Title 24 Questions
- What is Title 24?
- Do I need a Title 24 report?
- How much does a Title 24 report cost?
- How long does a Title 24 report take?
- What is included in a Title 24 report?
- What plans do I need to upload?
Frequently Asked Questions
The simulation runs in minutes. The time goes into collecting accurate inputs from the plans and fixing any item the model flags.
The software is available, but the certificate needs a documentation author and a responsible person to sign, and the program may not check mandatory measures.
Explore Energy Calculations
- Is a Title 24 Calculation a Prediction of My Energy Bill?
- Is There a Title 24 Calculator?
- What Software Is Title 24 Compliance Done In?
- What Is CBECC? The State's Free Title 24 Compliance Software Explained
- Why Do Two Title 24 Consultants Get Different Results for the Same House?
View all Energy Calculations guides → · Reports and Calculations · Title 24 guide