Hi everyone,

When I first started designing structures, I’d open a house plan and immediately look for something I could calculate.

A beam. A lintel. A column.

It felt productive.

It was usually premature.

Because before you size any individual member, you have to understand how the structure works as a whole. A one-storey timber-framed house on columns looks simple from the outside. But there are a lot of decisions hidden behind that simple appearance.

Looking at this house, the first question isn’t “what size beam do I need?” It’s a handful of others:

• Which way will the roof trusses span, and where will the girder trusses land?
• Which walls will carry roof loads?
• Where can the beams and columns go ?
• Where does the bracing go, and is there enough usable wall in both directions?
• How does the house tie down against uplift, roof to foundation?

Answer those questions, and the structural layout begins to reveal itself.

Skip them, and you can size a beam perfectly and still end up with a layout that doesn’t work.

A correct calculation won’t save a design that doesn’t make sense.

So before I touch any calculations, I run a quick pre-design process. It doesn’t replace the calculations. It gives the calculations direction.

The first part is relatively simple, and you can start practising it today.

First, read the architecture.

Before anything structural, look at the building shape, roof geometry, openings, verandahs, wet areas and any changes in floor level.

The wet areas matter because they may require set-downs for tiles and falls, which will influence the floor framing later.

The large openings matter because some of them may not be practical to support with timber.

Then trace the loads from the roof down.

Start at the roof sheeting and follow the load through the trusses, into the walls and roof beams, down through the floor framing, into the columns, and finally into the footings.

Do this and you stop seeing a floor plan and start seeing a load path.

You can feel where the load wants to go.

You can practise that much on almost any house plan tonight.

But here’s where it stops being a checklist:

Decisions about lateral stability, structural layout, member sizes, connections and footings require engineering judgement.

On most houses and structures, there is also more than one defensible solution.

This part is much easier to demonstrate than explain in an email.

That is what I want to show you live.

This particular house is a good example because it looks straightforward at first, but it contains several interesting design decisions once you look more closely.

Tomorrow, I’ll work through the key decisions live on this exact plan, starting with the architectural drawings and developing the initial structural layout with you.

The focus is the engineering thinking that comes before the detailed calculations.

Thursday, 25 June at 6:00 pm Brisbane time.

The live call is for BengLab members.

Not a member yet? Join BengLab here to attend the live session, access the learning library and join future design calls.

See you tomorrow,

Gabriel

P.S. If you have any questions, just reply to this email. I read and answer them myself.