The International Code Council (ICC) and the University of Miami have been hard at work on the ICC 815 Standard for Sizing Water Distribution, Sanitary Drainage and Vent Piping Systems. This new standard will mark a turning point for water supply and sanitary drainage pipe sizing, which together haven’t received a meaningful update since the 1940s. At that time, remote work didn’t exist and people lived in homes with just one bathroom or lived in buildings with fewer floors. This made it easy to predict water usage and install pipes accordingly.

For the new ICC 815 Standard, the University of Miami used a series of tools to identify factors that influence residential water usage patterns, including habitable area, household size, occupancy makeup, climatic factors and regional variations. Through this research, they were able to identify which factors had the strongest impact on demand estimation and water use.

The University of Miami explored how these factors could influence the prediction of peak flow rates using a novel network-based design methodology that makes it possible to record the maximum expected flow rate for each pipe in a system.

With this information, engineers and designers will be better equipped to design plumbing systems that are based on a broader set of performance metrics and are thus more likely to match the water use of a particular building.

An Academic-Led Solution with Technological Innovation

ICC and the University of Miami are also working on a software package to support the ICC 815 Standard. The Design of Robust International Plumbing Systems^TM (DRIPS^TM) software is being developed to serve as a link between the University of Miami’s incredible research and the resulting standard to improve pipe sizing in a user-friendly manner for engineers and designers.

With so many possibilities, the DRIPS^TM software will help to avoid the pitfalls of guesswork. The software models likely scenarios based on user inputs, including building type, and runs multiple simulations of random interactions between occupants and the building plumbing system to determine both normal and maximum use expectations. While worst-case scenarios (in which a building meets or exceeds the maximum daily use) must be considered, it is imperative for designers and engineers to understand normal use in today’s world.

Better still, the software will adjust according to each building’s size and location. That latter aspect is especially important because some regions have flow rate and pressure limitations and specific code requirements that must be considered during the pipe sizing process. For example, plumbing services in Sydney, Australia cannot exceed a maximum flow rate, water pressure or acoustic level. The DRIPSTM software accounts for all these factors and will streamline the pipe sizing process for all new residential occupancies, including multi-family buildings and mixed-use commercial properties around the world.

By accurately sizing plumbing pipes for each building, builders, developers, owners and occupants will benefit from significant construction cost savings from using smaller pipes and components, improved water hygiene due to an elimination of stagnant conditions within the water supply system, water and energy savings due to hot water reaching fixtures faster and a reduction in waste blockages in the sanitary drainage system.

Using building service data

Any number of scenarios can determine the likely demand on the water service and sanitary drainage systems of a building, but guesswork shouldn’t be part of the equation. There are buildings, such as restaurants, that offer a degree of predictability of occupancy rates through the occupancy limits required to meet existing requirements, such as fire and structural safety. However, restaurants are not likely to be at capacity at all times, and there are other building types that are much harder to gauge. Apartments are a good example – they could have a set number of units that are roughly the same size but contain a different number of occupants in each one. Before remote work, an office's occupancy may have remained stable throughout the week, but hybrid working arrangements have changed that.

To gain more information in this area, ICC has been using available building service data from around the world to refine and validate the prediction of outcomes. ICC also has several active projects around the world where the building services are being monitored to provide the essential high-quality data to continue to grow the supporting evidence and validation information from different building types across the globe.

This new standard will mark a turning point for water supply and sanitary drainage pipe sizing, which together haven’t received a meaningful update since the 1940s.

With all this new information and data being obtained, the need to ensure consistency in the methods used to select and install the equipment, as well as recording and storing the data, has become essential. To provide a solution in this area, ICC and the University of Miami have also published a paper to promote the System Performance and Data Extraction (SPaDE) Protocol to fellow researchers and the academic community. This protocol is intended to be developed into a new standard, ICC 820, and will guide future monitoring projects for building services.

Designed to grow and evolve

The ICC 815 Standard will not be a one-and-done solution. ICC will be involved in additional pipe sizing research for continuous improvement of both the standard and the DRIPS^TM software.

Upon publication, the ICC 815 Standard will be available for adoption and can be referenced or implemented as part of the existing codes and standards already employed in a particular region. Alternatively, ICC can use their extensive experience in regional and international adaptation and adoption of the I-Codes® to support any necessary regional-based changes. This will enable the development of specific versions of ICC 815 for use in Australia, Europe, the Middle East, New Zealand, the United Kingdom, and other countries.

ICC will also be developing the necessary training to demonstrate how to use the new design methodology of the ICC 815 Standard and provide ongoing support to designers and engineers.

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