February 6, 2023


February 6, 2023

A correct sanitary design can avoid future problems such as infiltrations, leaks and complicated maintenance, not to mention unnecessary expenses.

Unfortunately, it is very common for clients to believe that the plumber can solve this issue during the execution of the work, which can result in immense losses.

If you still have doubts about what constitutes a hydro sanitary project, I will explain each of its steps and why you should pay attention to this important phase of your project. 



A hydro sanitary project aims to map the entire plumbing system of a building, considering everything from water supply to sewage collection.

Much more than placing taps and drains, the hydraulic project determines how the water supply, distribution and drainage system will be, as well as the building's sewage collection system.

All this must be correctly integrated into the constructive system proposed by the architectural project, avoiding interference or even perforations in columns, beams or any other structural element.

It is very important to understand what are all the necessary specifications for your sanitary project to be correctly prepared, so we will know them below.



A sanitary project must contain:

  • Floor plans,
  • Isometric or 3D details,
  • Example images,
  • Detailed quantitative data.

Furthermore, it should act as a guide for the correct installation of the entire system.

We must also pay due attention to each of the systems present in a complete hydro-sanitary project, which in this case relies on the supply of cold water, hot water, sewage and wastewater collection, in addition to rainwater capture.

For a better understanding, I will explain each of these systems and the main precautions that must be taken.



The cold water supply system (room temperature) is composed of pipes, reservoirs, devices and points of use that must meet the needs of the building and, not least, preserve the quality of the water.

All requirements and recommendations relating to the project can be consulted in specific regulations of the country to which it is intended. In Brazil, for example, these standards can be found in NBR 5626 - Building installation of cold water.

Generally speaking, in a cold water system project, we must specify the following information:

  • Water supply system (direct, indirect or mixed);
  • Individualized water measurement system (hydrometer);
  • Reservoir sizing, when necessary;
  • Pipe path (columns, branches and sub-branches);
  • Specification of materials;
  • Specification of flow controller devices (taps, valves, etc);
  • Installation drawings (plan, isometrics, 3D, detailing, etc);
  • Pipe dimensioning.

Each project has specific needs which must be foreseen, for example, in some cases the water supply will be done by an artesian well.



The hot water supply system is powered by the cold water system and consists of heaters, safety devices and user parts.

In general, each country has its own standard with requirements and recommendations for the development of the project and execution of hot water building installations. In Brazil, for example, these requirements and recommendations are given by the NBR 7198.

  • In a hot water system project, you will normally need to specify:
  • Heating system;
  • Type of heater (electric, passage, gas, storage, etc.);
  • Heater sizing;
  • Pipe path;
  • Specification of materials;
  • Specification of flow controller devices;
  • Installation drawings (plan, isometrics, 3D, detailing, etc);
  • Pipe dimensioning.

It is important that the heating system is as close as possible to the point of use, as the water accumulated in the piping is not heated, which can cause a delay before the water is effectively hot for use.



The purpose of the sanitary sewage system is to collect and conduct waste from sanitary appliances, sending them to the public collection network or to the appropriate treatment system.

The requirements and recommendations necessary for the development of the project can be found in the regulations of each country. In Brazil, they are contained in the NBR 8160 - Building sanitary sewage systems.

Ithe design of the sanitary sewage collection system it is common to specify:

  • Sewage collection system;
  • Discharge branches;
  • Fat branch;
  • Disconnectors (siphon);
  • Siphon boxes;
  • Drains;
  • Inspection box and grease;
  • Ventilation branches;
  • Pipe path;
  • Specification of materials;
  • Installation drawings (plan, isometrics, 3D, detailing, etc);
  • Pipe dimensioning.

In the sanitary sewer system, the drainage takes place by gravity and it is necessary for us to consult the minimum slopes, in addition to avoiding sudden changes in the route.

In situations where the path change is 90°, installing an inspection box is necessary.



Responsible for collecting the water that originates from the rains, the project of the rainwater collection system consists of gutters, conductors, grates, passage boxes and other devices for conducting these waters.

The requirements and recommendations necessary for the development of rainwater building installation projects can be found in specific regulations. In the case of Brazil, they are found in the NBR 10844.

In a rainwater harvesting project, we usually have to specify:

  • Identify building coverage areas (roofs, marquees, etc.);
  • Identify impervious areas (yards, parking lots, backyards, etc.);
  • Project flow;
  • Gutters and flashings;
  • Vertical and horizontal conductors;
  • Collection box (in case of reuse);
  • Drainage systems;
  • Pipe path;
  • Specification of materials;
  • Installation drawings (plan, isometrics, 3D, detailing, etc);
  • Pipe dimensioning.

Rainwater should not be discharged into the sewage collection system, as it was not sized for this.

The drainage of rainwater is done through the “mouths of wolf”, which are usually located near the sidewalks. From there they are directed to streams, rivers and swimming pools.



In the architectural project, all the sanitary equipment and parts are positioned, but for them to work correctly, a correctly dimensioned sanitary project is necessary.

Showers, faucets, toilets, among other sanitary equipment, depend not only on the supply of water but also on adequate pressure, which often must meet different equipment connected to the same pipe.

Another advantage of the sanitary design is related to the savings in piping and accessories, in addition to the ease of maintenance, cleaning or even replacement of parts.



The first stage of a sanitary project consists of planning, where the sanitary items present in the architectural project must be analyzed and also:

  • Water supply system;
  • Waste collection system (sewage);
  • Number of residents;
  • Water pressure.

The second step consists of calculating the water consumption to determine the size of the reservoir, and then developing the path design for both water and sewage pipes.

Then we must position the flow control devices (discharge valves, mixers, valves, etc), essential items for both daily use and future maintenance.

Having defined the layout of the pipes, we must pay attention to the slopes (sewage system) and calculate the pressure required for each pipe.

Finally, we must organize all the information in an easy-to-understand project, identifying all the equipment, tubes and other accessories needed to carry out the project, in addition to a table of quantities.



The development of a sanitary project requires specific technical knowledge, which is usually developed in specialized software.

However, it is necessary to issue a term of technical responsibility for the project, which defines, for legal purposes, the technical person responsible for the project, which is nothing more than a guarantee for the developed project.

To issue the term of technical responsibility, specific technical training is required, such as architecture, civil engineering or building technicians.

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The hydro sanitary project guarantees the correct water supply and sewage collection of a building, being an indispensable item in any work.

It is very important to understand all the steps in the preparation of the hydro sanitary project, as well as to make the correct specification of piping, accessories and other equipment necessary for each of your systems.

A well-designed sanitary design provides a work of easy and quick execution, avoiding waste and unnecessary expenses with materials and labor.

Another must-have for your project is a good collection of templates, so get ahead by using Blocks Revit's family library where you can find a huge catalog with weekly updates!

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The author of the article

Luís André
Master of architecture, product designer and professor. Sharing professional content from leading architectural software for 10 years.
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