Residential home design to Australian standards

Setting up a project in Calcs.com for Australian residential design

Brooks Smith opened with the worked example: a lighthouse keeper's dwelling, chosen because it fits on a single plan document showing overall dimensions, framing plan, and notes all at once. Most real projects will be more complex, but the single-sheet example keeps the workflow clear.

Every Calcs.com project starts with a project details screen. All fields except the building standard are optional. The building standard defaults to your organisation's default but can be changed: Calcs.com supports Australia, New Zealand, the United States, Eurocode, and Canada.

Brooks described Project Defaults as the key time-saving tool for residential work. It is a sheet in every project where you enter values that will be used as defaults throughout: joist spacing, bearing length, headroom, wind class, and default roof, floor, and wall loads. Most of these can be overridden in any individual calculator. The one field that cannot be changed per calculation is load combinations: those are set once and apply across the entire project. If your organisation or a particular project requires special serviceability combinations, you can enter custom load combinations here.

For the lighthouse keeper's dwelling, Brooks set the wind class to C2 (cyclonic region), floor joist spacing to 600 mm, and headroom to 3500 mm. He set the roof loads by selecting a steel sheet plus ceiling option from the drop-down, which automatically populated the permanent load. The floor imposed load was set to 2 kPa.

Member presets, selection, and auto-sizing

Calcs.com provides presets for common member types: rafter, roof bearer, floor joist, beam, column, and others. Each preset opens the same underlying calculator but pre-loaded with the most relevant inputs from Project Defaults. A rafter preset opens with the roof slope and roof loads already applied. A floor joist preset opens with the floor joist spacing already set as the load width.

For sizing members, Calcs.com offers two approaches. The member selector shows every section in the database filtered by species, grade, manufacturer, or size, with traffic-light indicators for each limit state. Red means the section fails, green means it passes, yellow means it passes but is close to the limit. Preferred sections set in Project Defaults appear at the top of the list with a blue star marker.

The auto-size feature selects the most structurally efficient section from your preferred sections list with a single click: it picks the section closest to 100% utilisation without exceeding it. Brooks noted this is not always the most economical choice and encouraged engineers to use their own judgement after auto-sizing.

Preferred sections can be copied from a previous project without copying the entire project: a copy from another project option in the project details screen allows you to pull in preferred sections from any project in your organisation.

Following the load path with load linking

Brooks described load linking as the feature that replaces manual reaction copying between spreadsheets. You click the chain icon next to any point or moment load table in a calculator and link it to another calculator in the project. The link is persistent: any change to the upstream calculation automatically updates the reaction in the downstream calculation. Changes propagate through the full chain, from rafter through bearer through column through footing.

In the worked example, Brooks created a rafter at 3 metres span, linked it to a roof bearer at 5 metres, sized the bearer using the member selector, then created a column and used auto-size to find the most efficient section from his preferred set.

Reviewing, organising, and exporting calculations

Once the design is complete, the member schedule gives a summary of every member in the project. Members can be grouped by floor level, framing zone, or any other category by creating groups in the member schedule view. The quantity view shows how many of each member size are in the project and the total cumulative length for each, which is useful for material scheduling.

From the member schedule, you can edit a member's section directly using the edit button without opening the full calculation. This allows quick resizing if a member is shown as over capacity in the schedule view.

Calcs.com exports to PDF in three modes: one page (a single page summary per member), standard (the default calculation view), and detailed (every intermediate step shown). The archive function permanently saves a PDF export of the project at a point in time. Later modifications can be made to a duplicate, while the archived version is retained.