MAKING SENSE OF PRODUCER STATEMENTS AND CONSTRUCTION MONITORING

Let’s start at the beginning. Any construction needs to meet the NZ building code. Construction over a certain size needs to go through a regulatory process to ensure that buildings meet this standard. From the plans to the construction, there are different touch points along the way to check the final construction will make the grade. Engineers have a specific role within this process.

PRODUCER STATEMENTS

Choosing and using the right materials in an engineering approved design is an important part of ensuring the building will be fit for purpose. We want to know that a building will be structurally sound in an earthquake and the windows of a high rise will withstand strong winds for example. This expertise is provided by Chartered Professional Engineers (CPEng). Engineers use a standardised document called a  Producer Statement (PS) to show that a proposed building element complies with the NZ building code.

Producer Statements can help support building consent applications and can be required at different stages of the consent. They are not a product warranty or guarantee of compliance – but they set the standards for the construction teams to follow.

There are four levels of Producer Statement. PS1 and PS2’s occur in the design stage, while PS3s and PS4s occur in the construction and monitoring stages.

• PS1 – A CPEng’s opinion on whether or not a design is compliant with the relevant sections of the building code.
• PS2 – A second CPEng’s review and verification of the first engineer’s work.
• PS3 – The contractor’s word that the system has been installed/built as per the PS1.
• PS4 – A CPEng’s check that the installed/built system aligns with the PS1.

CHANGES TO DESIGN

In the real world, changes to designs happen frequently. The specified product may not be available, services could be added, or other design changes could have a knock on effect. If the design change happens before consent, a PS1 revision (by the engineer) is generally issued. Following consent, a consultants advice notice (CAN) is used. A CAN is used to provide information for small design changes or clarifications throughout the construction process.

CONSTRUCTION MONITORING

Once construction is underway, Construction Monitoring kicks in. Construction Monitoring is the on-the-ground checking of the construction process as it takes place. It is done by a specialist (usually an engineer) and adds value where specialist knowledge is required. The purpose is to ensure that an engineering design is understood correctly and built accordingly. This includes using the right materials, with appropriate levels of workmanship. The engineer helps interpret and communicate the design to those carrying out the work through Requests for Further Information (RFIs).

THERE ARE 5 LEVELS OF CONSTRUCTION MONITORING

• CM1 doesn’t include any review of as-built components, there is full reliance on the contractor’s inspections. CM1 can include advice on the technical interpretation of plans, as well as the review of important materials and work components. This should not be the primary level of review.
• CM2 is an appropriate level for smaller routine projects such as a small office fit out. Representative samples of key design elements such as seismic braces and connection details are required to be inspected to ensure the correct materials and construction methods have been used. The  compliance of the finished work is then dependent upon the installer completing the work to at least the same standard as the representative sample reviewed.
• CM3 includes random sampling of important work procedures. For example, the review of typical shop or office fit-outs. Brevity recommends sampling at least 33% of each design feature ensuring these samples are spaced throughout different areas in the build to ensure there is a consistent quality of work.
• CM4 – The required sampling steps up from random to frequent in CM4. This level of service is appropriate for larger projects such as Auckland Town Centre or the Canterbury University’s  new engineering block. To ensure work methods and materials meet this level of compliance, Brevity recommends sampling 66% of each design feature across as much of the project as possible.
• CM5 – This is the highest level of Construction Monitoring. This level of Construction Monitoring is typically only seen on major projects where work poses a critical risk to life safety such as hospitals or large scale buildings where lots of people can congregate such as shopping centres.

THE LEVEL OF CONSTRUCTION MONITORING REQUIRED DEPENDS ON A NUMBER OF FACTORS 

• The size of the project
• The Importance Level (IL) of a project
• The complexity of the project
• The experience and skill of the constructor

CM3 will generally provide the level of information required for Council to sign the building off for code compliance. However, to have the confidence that as-built construction meets all its contractual requirements may require more in depth Construction Monitoring.

Contact us to find out how the Brevity team uses our extensive seismic expertise to deliver value engineering solutions with our trademark efficiency. We’d love to discuss your next project, and how we can support you.