To counter this anomaly, worked into every contract is a thing called a "shop drawing" where the builders attempt to understand what the architect's intent is by creating a set of drawings which explain how something is to be built. The architect then approves it, and if it forms a variation to the intial scope of works, the owner/client will also need to approve it.
In our case, the owner, the client, the architect and the builder being one person, sign off is often a quick and easy process.
Here are our shop drawings.
(above) proposed detail at joint of lime render to exposed timber joist.
(below) room elevation and extent of mezzanine stair.
(above/below) detail of render and straw bale wall at window reveals to south wall.