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Builder’s Jargon Explained

When it comes to understanding builders jargon, the list of specific terminology used day to day seems endless! This little guide should help to break some of it down so you have confidence when speaking about your new build!

Provisional Sum (PS)

A Provisional Sum, more commonly known as a PS, is an allowance that the builder has made to complete a task. They are useful when the final selections have not been completed or it is simply not possible to include a quote due to factors that are unknown at the time of signing the contract

A PS is effectively an estimate which could potentially change when the final cost of the task has been calculated.


Prime Cost Item (PC)

A Prime Cost Item is a dollar figure allowance used in building quotes and contracts. It’s an allowance for materials such as appliances, sinks, taps etc. Essentially a dollar budget where the final selection of those items is still to be confirmed. Just like provisional sums, prime cost items price can change depending on your final selection and therefore can incur additional costs, for instance if you select to upgrade something where a standard item was priced.

Note that the allowance for a Prime Cost item only covers the supply of that item. Any labour associated with the installation of that item should either be included in the contract or listed separately as a provisional sum.


Preliminary Building Agreement/Contract (PBA)

A Preliminary Building Agreement or Preliminary Building Contract are also referred to as ‘pre-lims’ by builders. They are a pre-contract document that includes all of the tasks that need to be organised prior to signing a building contract.

Engineering, soil tests and working drawings all need to be completed in order to produce a fixed price contract. A professional builder will always start with a Preliminary Building Agreement before committing to a full building contract.


BAL Rating

BAL stands for ‘Bushfire Attack Level’ and really is a scale rating of how likely it is and to what effect that a building could be under threat by a Bushfire. The Bal Rating will determine if there are any special requirements for construction materials to be used – for instance upgraded glass for windows and doors and non-combustible timbers for decking.


Extension Of Time (EOT)

An Extension of Time is simply the amount of days that are added to your building contract. These usually appear once you add a variation to your contract that will delay the completion or it can be due to inclement weather or any other reason outside of the builder’s control. EOT’s simply extend the contract completion date of your new home that was recorded in your building contract.



Variations can get introduced for many different reasons. The most popular reason for a variation being raised is when you change your mind on something after the contract has been signed.

Variations document what has been changed along with any additional costs that relate to labour, materials and administration fees.


Rock Clause

Finally, a rock clause is something you’ll find in most building contracts. It is there to protect your builder from unfortunate unforeseen circumstances like hitting rock during the excavation. The rock clause applies to fixed price contracts so be aware. You can’t avoid it but you can certainly be prepared for it.


Hopefully this helps to clear up some of the frequently used terminology in the building industry! Though at Pase Homes we always ensure that we speak to all our clients in language that they understand and are always prepared to answer any questions that you may have about anything you don’t understand. This is your house we’re building after all and we like to ensure that our clients are never left unsure. And there are no silly questions!

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