Residential home design to American standards

Setting up a residential project in Calcs.com

The webinar uses a historical lighthouse keeper's dwelling in California as the worked example. Laurent and Connor start by creating a new project, entering the project name and number, client information, and site location. Selecting the location activates the built-in standards lookup and sets the applicable US code framework.

Project defaults are configured before any member calculations begin. For this example the team sets a roof pitch of 8-in-12, floor height of 10 feet, and rafter spacing at 16 inches on-center. Gravity load defaults are entered as a snow load of 40 PSF, roof live load of 20 PSF, and floor live load of 40 PSF. Laurent notes that all of these values can be overridden at the individual member level, so the defaults represent the typical case while non-standard conditions are handled per member.

Preferred lumber sections are also configured at the project level: Douglas fir dimensional lumber by grade, plus LVL options. The system draws on this list when auto-sizing members, so the engineer controls which sections are candidates without entering sizes manually each time.

Configuring gravity and wind loads

Snow and live loads flow from the project defaults into each member automatically. The presenters work with a snow load of 40 PSF and a roof live load of 20 PSF for the lighthouse project, with a floor live load of 40 PSF carried through to the floor framing members.

Wind loads are calculated using the ASCE Hazard Tool. For the lighthouse location, the team derives a design wind speed in the 92 to 100 mph range. The webinar covers enclosure type in detail: classifying a building as partially enclosed is the more conservative approach because it produces higher internal pressure coefficients during a wind event. Engineers select the enclosure classification in the calculator and the design pressures update accordingly.

Sizing members using the auto-size feature

The workflow for sizing individual members follows a consistent pattern: select the member type (rafter, floor joist, stud wall, or footing), enter the span length and tributary loads, then run the auto-size function. The platform evaluates every section in the preferred lumber list and returns the smallest member that satisfies all governing checks.

In the live demonstration, a roof rafter initially assessed as a 2x12 is reduced to a 2x10 by the auto-size routine, landing at approximately 70% utilization. Laurent walks through the utilization ratios for bending, shear, and deflection and explains how the result is read. The same workflow applies to floor joists, stud walls, and footings: each member type has its relevant checks built in, so the engineer reviews utilization ratios rather than running manual code lookups.

Cascading loads through connected members

The load linking feature is the central workflow demonstrated in the webinar. Once members are connected in sequence, changes to upstream loads automatically flow downstream with no manual re-entry required. The sequence in the example runs: rafters carrying roof loads into a ridge beam, which bears on a second-floor stud wall, which transfers load through floor joists to a first-floor stud wall, and finally into the foundation footing.

Connor explains the practical value: if the roof load changes, the updated reaction propagates all the way to the footing without the engineer manually updating reactions at each step. As he puts it, changes "would carry down all the way to here with no problem." This eliminates transcription errors and ensures every member in the load path reflects the same upstream conditions.

Exporting calculations and archiving finished projects

Three export modes are available for generating submittal-ready PDFs. The one-page summary mode produces a single page per calculation, suitable for appending to drawings. Standard mode runs three to four pages and includes calculation descriptions. Detailed mode is comprehensive and can run ten to twenty or more pages, showing every intermediate calculation step for full transparency.

The archive feature locks a completed project and preserves the PDF record. Archiving prevents accidental edits to finalized calculations. A copy function creates an editable duplicate of the archived project, allowing the engineer to reuse the setup for a similar job without altering the original record.