Sample Engineering Drawings
It’s hard to explain what structural engineers produce when we do structural engineering for a new house. So I’ve prepared a sample set of our structural engineering house plans for your enquiring mind!
This example set of plans is for a single storey house with a concrete slab on ground, concrete Besser block masonry walls and a timber roof trusses.
Let’s go through some of the aspects of what makes these sample engineering drawings so special.
Sheet S1 – The Project Specific Notes
Our first page contains the projects specific notes. We’ve called them Project Specific notes because we revisit these notes for each and every project.
Other companies might use Standard Notes as the first page of their drawings. These notes need to be specific to each project because they are very important.
There is a section of notes for each major form of construction in the job. For example for this house there are:
- general notes that describe the wind speed the house has been designed for, a warning not to scale off the drawings, the design floor loads used to prepare the drawings, and a note that if trade names have been used to specify a product that an equivalent product may be used from a different supplier.
- foundation notes that explain the expected ground conditions and how the builder should treat them.
- concrete notes that dictate the minimum concrete grade for different aspects of the project, minimum concrete cover to the steel reinforcement, the required slab curing and the grades of steel reinforcement to be used.
- concrete masonry notes that explain the required compressive strength of the concrete Besser blocks and the corefill, the minimum grout cover tot he reinforcement and the special instructions to the builder for not cutting chases in the wall and propping retaining walls.
- structural timber notes that describe the minimum expected timber grades to use, the timber dimensional tolerances, the corrosion protection requirements for bolts and screws and a fallback statement referring the builder to AS1684.3 for any elements not specified on the drawings.
Sheets S2 and S3 – Safe Design Notes
Sheet 2 and Sheet 3 of the sample engineering drawings contain the notes relating to the safe construction of the dwelling.
Sheet S4 – The Footing and Slab Plan
Our sample drawing shows a typical raft footing and slab design to AS2870 on Sheet S4
Our footing and slab plan is drawn at the standard metric scale of 1:100.
The footing and slab plan features:
- EB1 and EB2 edge beams to the perimeter of the slab.
- SF1, SF2 and SF3 strip footings through the middle of the slab spaced out to comply with AS2870.
- Slab thickenings under bracing walls that do not otherwise have strip footings or edge beams under them.
- A schedule in the top right hand corner which clearly describes the dimensions and reinforcement for the edge beams and strip footings and slab thickenings.
We show three parallel diagonal lines across re-entrant corners as required by AS2870 to minimise the propagation of shrinkage cracking at these stress points.
We show the slab thickness in a hexagon and the require top cover for the internal and external concrete slab areas. Correct placement of the steel mesh reinforcement towards the top of the thickness of the slab minimises shrinkage cracking and ensures sufficient concrete ‘cover’ to prevent corrosion fo the reinforcement.
Drawing S4 also has the requirements for reinforcing the Besser block walls specified in the “Concrete Masonry” notes.
Finally, sheet S4 has the Special Requirements for building on (in this case) a Class “M” site. These notes include requirements for surface drainage, trench drainage, plumbing joints, trench backfill and the presence of trees.
Sheet S5 – The Footing and Slab Details
Our footing and slab details are drawn to a standard scale of 1:20 and are dimensionally correct to help us identify any potential clashes.
Drawing sheet S5 of our sample engineering drawings provides the exact way we expect the edge beams, internal strip footings and slab thickening to be constructed.
Sheet S5 also shows the footing specification at the timber post, the special requirements for slab step downs at wet areas, how the concrete masonry corners are to be reinforced, how the footing corners are to be reinforced,
Where possible we order our footing details on the page as if they were a cross-section through the slab so that the builder and concrete can quickly locate the specific details they need.
Sheet S6 – The Bracing Plan
The bracing plan doesn’t just specify bracing although that is the primary purpose of Sheet S6.
The reason bracing is so important is that it is so crucial that the bracing walls align with the slab thickenings shown on the footing and slab page. Bracing walls need sufficient concrete thickness under them so that the concrete does not crack when the bracing walls are loaded in a storm.
The other aspects that are specified on our Sheet S6 include:
- Roof beams. Where they are located and what size they need to be.
- Timber lintels (L1) which are the timber beams over doorways and window openings in the internal timber-framed walls.
- Besser block lintel sizes and reinforcement specifications for openings in the external Besser block concrete masonry walls.
- Timber framing notes for the internal loadbearing and non-loadbearing walls.
- An easy to read schedule that describes those major timber beam elements.
Sheet S7 – Roof Framing Details
We deliberately draw the roof framing details to scale for every project. This takes time to get the height of each beam right. However, it is super-critical that these details are easy to understand and easy to build.
Have you heard the saying that a chain is only as strong as the weakest link?
Any engineers or designers that scrimp on these roof framing connection details are hoping (and praying) that the builder will get these connections right and yet they are not giving them any help.
We firmly believe that drawing these specific details for each project is one of the critical points of difference we offer to clients (builders and homeowners alike). We already know our connection details will work because we have drawn them to scale!
(Sorry to the other engineers and designers that take shortcuts at this step – we don’t really expect that you can compete with our beautiful engineering drawings.)
Sheet S8 – The Bracing Details
The bracing in a building is what ties the building together. Bracing walls transfer wind loads and earthquake loads from the roof and upper floor levels to the footing and slab level.
Again, a chain is only as strong as the weakest link and there is no point having plenty of bracing capacity if there is no design for how the load gets into and out of the bracing walls – ie the bracing wall connections.
On Sheet 8 of our sample engineering drawings we take special care to ensure not only are our bracing walls well spaced out and strong enough, but that the bracing walls are connected to the roof framing and floor framing above and the slab/floor framing below.
We even provide connection capacities so that the builder knows HOW MANY of each connection are needed.
Construction of houses (well actually we see them as people’s homes) is critical to the safety and well-being of the occupants. Do you really want your engineer/builder/designer taking shortcuts on your bracing?
Start Copying our Sample Engineering Drawings
We’re not going to make it easy for you if you are an engineer or designer – but we firmly believe we have set the bar high for engineering of residential structures (homes).
So if you are an engineer and your drawings are not as easy to read or as neat and well-presented as our draiwngs, the least you can do for your clients is to start to copy our details and our layout.
If you’re designing a slab on ground and not taking into account the location of the bracing walls and the tie-down points and the roof beams and the lintels then I’m glad you have clients that don’t really care if you’re doing a good job.
If you’re designing houses and not specifying wall framing, roof beam connections and bracing connections then WHY AREN’T YOU? It isn’t that hard. it is not fair to builders and homeowners to leave everything off your pages and instead refer them to some manual or another. Put these things on your drawings and let’s improve the construction industry.
Until then, we’re happy to set the standard for engineering design and drawings for residential construction..
Our Drawings are Excellent
What’s so great about the drawings that we produce?
- They are clear and concise.
- They are easy to read and build from.
- They are backed by our 20 years of experience and local knowledge.
We pride ourselves on the fact that so many of our houses get built without the builder needing to ask us any questions. We think about our designs to make it easier (and cheaper) for the builder. Doesn’t that sound like a good idea?
Want to know what goes into checking our engineering plans? Check out this video of a structural engineer checking engineering plans.
We’re super-keen to help you with structural engineering for your house. Contact Matt Cornell and the team to arrange a quote today!