Manual J Load Calculations

We offer Manual JS Services for Permit with fast turnaround and 24h Delivery Available!
Over 20 years of experience and using ACCA approved software.

Permit-Ready Manual J and Manual S Reports

We prepare residential Manual J load calculations and Manual S equipment-sizing reports for permit submissions.

Our reports calculate heating and cooling loads using your home’s plans, insulation values, window specifications, orientation, local design conditions, and much more.

Before ordering, confirm your building department’s exact submission requirements.

Two-page document: left is a compliance report, right is a first-floor floor plan with blue outlines and room labels (Kitchen, Dining, Living Room, bedrooms, bathrooms, garage).

What is included in your permit package?

Our Manual JS permit package includes ACCA-compliant Room-by-room or Blockload Manual J load calculations and Manual S equipment selection. You’ll receive a professional report showing the home’s heating and cooling loads, design conditions, building specifications, and properly sized HVAC equipment—ready for permit submission.

The Report IncludesACCA Manual J load calculations + Manual S equipment selection
Who needs itHVAC contractors, builders, architects, and DIY homeowners pulling a mechanical permit
PriceBlockload: $100 under 2,000 sq ft | $0.05 over 2,000 sq ft
Room by room: $140 under 2,000 sq ft | $0.07 over 2,000 sq ft
Turnaround3–4 days (express delivery available upon request)
SoftwareWrightsoft (ACCA-approved)
AcceptanceAll 50 U.S. states
Prepared byBobby Blough – 20+ years as a Master HVAC (NJ) and 15+ years as HVAC System designer with over 13,000 completed projects.
Other servicesManual D, ERV/HRV design, Radiant design, ResCheck, Florida R405, Material takeoff.

When do you need a Manual J calculation?

A Manual J calculation is typically required when installing or replacing an HVAC system, building a new home, completing an addition or major renovation, or applying for a permit. It accurately determines each room’s heating and cooling needs so the equipment can be properly sized for comfort, efficiency, and code compliance.

How Manual J and Manual S Ensure Proper HVAC Sizing

Manual J determines how much heating and cooling each room and the entire home requires. Unlike outdated square-footage rules of thumb, it accounts for the building’s actual construction and local climate conditions. This helps prevent oversized or undersized HVAC equipment that can cause poor comfort, inefficient operation, increased energy costs, excess humidity, and a shorter system lifespan.

Manual S uses the Manual J results and the manufacturer’s performance data to select properly sized heating and cooling equipment. Because HVAC equipment does not perform at its advertised capacity under every climate condition, Manual S verifies that the selected system can meet the home’s calculated loads at the local outdoor design temperatures.

Together, Manual J and Manual S provide a reliable basis for selecting an efficient, code-compliant HVAC system that delivers balanced comfort and dependable performance. Manual S is included with our Manual J service at no additional charge.

Manual J vs. Manual S: what is the difference?

Manual J calculates how much heating and cooling your home requires, while Manual S uses those results to select properly sized HVAC equipment based on the manufacturer’s performance data. Together, they help ensure an efficient, code-compliant system.

Information we need to get started with Manual JS

To prepare an accurate Manual J load calculation and Manual S equipment selection, please provide the following information.

Floor Plans
Your floor plans should clearly show:
– Dimensions of all interior walls including hallways and closets
(For Blockload, I need only the measurements of the exterior walls)
– Room names
– Window, skylight, and exterior-door locations and sizes (W × H)
– Ceiling heights
– Vaulted or sloped ceilings, including the low and high points or roof pitch
– Insulation values for the walls, ceilings, and floors
– Window type and U-factor, if available

Official architectural plans are preferred but not required.
If professional plans are unavailable, you may submit a clear, accurately measured hand-drawn floor plan. Graph paper is recommended to help maintain proper scale. Please double-check all measurements before submitting your drawing, as inaccurate information may affect the final calculations and design.

HVAC System Information
The type of HVAC system being installed, preferred equipment brand, and the number of desired systems.

Sample floor plan showing room dimensions, room names, ceiling heights, windows, doors, and skylights required for a room-by-room Manual J and Manual S calculation.
Download a sample floor plan showing all required project information.

Frequently Asked Questions (FAQ)

Learn what’s included in your package and what’s needed to get started.

Price Quote

If you’re ready to get started, request a quote today.

Simply submit your floor plans, and we’ll provide a fast, itemized quote within an hour.

get a quote