Design of Constructive System for rainwater harvesting
Self-build housing + rainwater harvesting + water container
This research is my master of engineering dissertation, it is an academic effort to provide a solution proposal with a holistic approach of Mexico City reality from a User-Centered Design perspective, starting by identifying the User and its peculiarities, in order to offer a social interest solution that improves people’s quality of life while having a positive environmental impact.
A real problem
The Constructive System for Rainwater Harvesting is a viable solution for the water shortage in Mexico City that has been a persistent problem, in addition to overcrowding, the population needs exceed the state ability to satisfy them. Only in Iztapalapa district, there are 600,000 inhabitants living on 8.3 liters per day, while the minimum established by the Mexico City state is 50 liters*person/day. While there is water shortage, the local aquifer mantle has been over-exploited causing sinking all around the city and many problems along with it.
The objective was to design a constructive system for low cost housing that harvests rainwater on the rainy season and contains it to be used on the dry season.
The proposed design is a viable solution to mitigate the water shortage for the most unprotected citizens, and at the same time to reduce the flow demand on the local aquifer mantle. The structures built with this constructive system will capture rainwater dropping on the roof, filter it and chlorinate it by the rain-gutter system and store it inside the walls for human use.
A part of the user-centered design perspective and social approach was to facilitate self-build to poor citizens, owners can construct their own home, with a constructive system whose pieces are designed for easy transportation and assembling with no special tools or crane required.
Optimizing space.
In addition to the housing and rainwater harvesting system and water container, the constructive system includes the use of vertical garden or orchard (for environmental purposes and thermal advantages).
Manufacturing material
I chose PET as recycled manufacturing material for the Constructive System, due to the extreme production of trash (mainly from beverage containers) in Mexico City, reducing the volume of solid waste going to the landfill. The Constructive System could be manufactured with other recycled material, but the specific geometric dimensions should be recalculated for the specific recycled material mechanical properties.
All pieces are designed to be extruded for its qualities of high production at low cost. Of course, it will require a sizable machine.
Designed to comply with Mexico City building regulations
Among my objectives was that the proposed Constructive System for Rainwater Harvesting should comply with the construction regulations and laws:
Mexico City building Law.
Technical rules for: Wind design, Design and execution of hydraulic installations, Foundations design and construction, Earthquake design, Structural Design, Water law of Mexico City, Regulation of urban development.
Solutions to real problems should consider engineering, social and legal requirements to promote its implementation; besides, regulations shape and guide the design process while aiming for novel ideas.
Flexible water containers are hidden inside every wall module, except where windows and doors are required.
Flexible water containers are hidden inside every wall module. White pipe conveys rainwater into the flexible water containers, while red pipe redistributes water evenly between flexible water containers via hydrostatic pressure.
Having water contained in the walls of the structure means a lower center of gravity, contrary to on-top water containers, allowing a bigger built-in water reservoir on earthquakes zone.
Build your own rainwater harvesting house or warehouse
Render of a house built with the constructive system for rainwater harvesting.
Render of a warehouse placed on top of a traditional one-story house.
Self-build one-story houses up to 92 m^2 .
The Constructive System for Rainwater harvesting is a modular system to build houses, warehouses or any structure under 92m^2, inside Mexico City.
45m^2 houses build will harvest and contain enough water for 2 persons, while,
86m^2 houses will harvest and contain water for 4 persons, that is 50,169 liters per year per house (equivalent to five 10 tons tank-trucks completely filled with water each year per house).
Modular design
The Constructive System for Rainwater harvesting is formed by 10 different pieces that assemble with each other like a 3D puzzle repeatedly in any configuration with a resolution of 1 meter to fit any construction blueprints. These 10 pieces account for the housing, rainwater harvesting system and large capacity container.
All proportions of the proposed constructive system are under construction industry standards, for example, wall thickness is 18 cm: including double PET boards and a flexible water container. External (with flexible water containers) and inner walls (no water container) can be placed to divide the building while maintaining distances stated by building regulations.
General View of a sample house.
Video showing a general view of a rendered sample configuration of a house built with the constructive system for rainwater harvesting.
Assembly: 10 pieces make a house with rainwater harvesting capability, and large water container.
10 pieces ensemble again and again can build any configuration. Accounting for external and internal walls.
Design to be assembled and disassembled to modify, extend or reallocate the buildings.
Design for a fast building . It would take 4 persons and 3 days to build a 80 m^2 house. With no special tools or crane required.
