What software are the calculations run in?

CEC-approved compliance software. The Energy Commission publishes CBECC as public-domain compliance software, and approved third-party tools must meet the same ACM rules.

Prescriptive or performance — which will you use?

Whichever gets your design approved. Performance modelling is the more common route because it allows trade-offs between measures.

Can calculations be reused on another project?

No. The energy budget is climate-zone specific and the model reflects your building's geometry and orientation, so each project needs its own.

Title 24 Calculations

Energy calculations run in CEC-approved compliance software and delivered as a permit-ready report — from $199 in 2–3 business days.

"Title 24 calculations" refers to the energy modelling behind your compliance report. Your building's envelope, orientation, glazing, HVAC and water heating are entered into CEC-approved software and evaluated against the requirements for your climate zone.

Two ways the calculation can be done

The prescriptive approach is a checklist — meet each listed requirement and you comply. Simple, but rigid: miss one item and you fail, no matter how the building performs overall.

The performance approach models your proposed design against a standard design and compares energy use to a budget. If your building meets the budget it complies, even where individual components fall short of prescriptive values. That is what allows trade-offs — more glazing offset by better insulation or more efficient equipment. Performance is the more commonly used route precisely because real designs rarely match a prescriptive package exactly.

Why the climate zone changes the numbers

California has 16 building climate zones, and the energy budget a performance model is measured against is zone-specific. Envelope and fenestration requirements vary too. The practical consequence: identical buildings can pass in one zone and fail in another, which is why calculations cannot be reused from a project in another city.

What we need to run them

Dimensioned floor plan with a scale
Elevations showing window and door openings
Window schedule — sizes, plus U-factor and SHGC if selected
Roof and framing assemblies
Intended HVAC and water heating equipment
Project address — it determines the climate zone

If equipment is not chosen yet, we can model reasonable assumptions and state them clearly for you to confirm. What we will not do is invent a value and leave you to discover it at plan check.

Pricing

ADU — from $199, includes up to 1,000 sq ft
Residential — from $245, includes up to 3,500 sq ft
Multi-Family — from $345, includes up to 4,000 sq ft and 4 units
Commercial — quoted after we review your plans, free

Additional square footage is itemised in the order form, so the figure you see before paying is the figure you pay. Two revisions are included. 24-hour rush is $99; 4–6 hour priority is $199.