Architecture
In this project, 44% of all RFIs were allocated to the architects, making them the largest source of RFIs. Within this group, more than half were due to missing information, while around a quarter were related to design errors.
Comparing the volume and cost of RFIs reveals some important insights. While missing information accounts for a greater number of RFIs, the cost of those triggered by design errors is significantly higher - more than double, in fact. This is not surprising, as it can be straightforward to provide missing information, but design errors often have a multitude of knock-on effects.
The high number of RFIs reflects not only the scale and complexity of the project but also the inherent challenge of delivering precise detail across every element of the design. They also highlight the increasing pressure architects face in today's budget-driven environment. Clients expect highly detailed, technically complex designs within often tight, and at times unrealistic, timeframes. This challenge isn't unique to New Zealand; it's part of a broader global trend affecting the industry.
Structural Engineering
Structural RFIs made up 36% of the total. In this discipline, missing information led to higher costs than design errors – a reversal of the architectural trend. The reason? This cost difference is often due to the need for last-minute solutions on site. When key details are missing from structural drawings, contractors must source materials quickly to stay on programme, usually at a premium, leading to expensive workarounds and time pressures for the site team.
Building Services
Although fewer in number (17% of RFIs), building services RFIs had the highest average cost per CI: $36,000. This reflects the difficulty of resolving services issues late in the process, especially when systems must be realigned across multiple trades.
Response times were also the slowest. This is likely due to the performance-based nature of many services specifications and the high level of coordination required across multiple systems and trades - such as HVAC, electrical, and plumbing. Aligning changes can be complex, often involving several parties, which contributes to longer response times and increased downstream costs.
Geotechnical
Despite their low volume, geotechnical RFIs had the highest average cost at $75,000 per RFI, reflecting the significant unpredictability and expense involved in understanding site conditions before construction begins. They also took the longest to resolve, averaging 29 days, 36% longer than the average across all disciplines.
Given the complexity and cost implications, it's essential that geotechnical aspects receive early attention during the design process.
Passive Fire and Civil
Passive Fire contributed under 3% of RFIs, which is expected given its relatively small scope within the overall project. Most of the RFIs were due to missing information. While relatively inexpensive to fix, these RFIs still caused avoidable delays, highlighting the need for early integration of fire requirements. It is important to note that for other recent projects poor passive fire design can significantly impact the project negatively.
