Architectural Theory, Building Design, Design Guide, Design Theory, Sustainability, Sustainable Materials

10 Water Efficiency Methods For Green Building Design

In most of our design projects, when it concerns water efficiency, we add a rainwater harvesting system and a couple more generic water conservation methods and call it a day. 

List of water efficiency methods in architecture

There’s much more to water conservation than we may generally know. Water, being one of the most essential resources to us, needs to be given priority in every building design. Some of the methods for water efficiency that can be followed while designing green buildings are:

  1. Rainwater Harvesting
  2. Greywater Recycling
  3. Rain Gardens
  4. Drip Irrigation
  5. Pressure reduction
  6. Plumbing Fixtures
  7. Water treatment plant
  8. Wastewater recycling
  9. Water catchment systems
  10. Drought resistant landscaping

1. Rainwater Harvesting

Rainwater is an essential resource that must be made most use of while setting up a site for water conservation. 

Surface runoff harvesting

The rainwater runoff can be redirected from the roofs, ceilings and slopes to be storage units for future use.

Groundwater recharge

Rainwater seeps into the ground from the surface into the ground and improves the groundwater levels in the site. This helps in better vegetation growth and the overall health of the soil.

House in the Countryside by Herreros Arquitectos has an inverted roof that collects rainwater
House in the Countryside by Herreros Arquitectos has an inverted roof that collects rainwater

2. Greywater Recycling

The level of contamination and reusability of water depends upon the purpose and is often subjective. Primarily, the water that is uncontaminated by any chemical or used sparingly can be recycled to give it another purpose.

Direct Use Systems

These systems redirect the greywater into another channel using valves for quick reuse before potential bacterial buildup from the first use.

Mechanical Filters

Greywater can be transported using pumps to carry the water vertically to a storage tank. The water is then treated before it is repurposed for the last time.

Sand Filter

Removes unwanted large particles in the water with the help of gravity. By passing through the four layers of soil, the water in turn gets purified.

Wetland

Stagnant water is made use of to grow aquatic plants. The aerobic and anaerobic bacteria present in the water purifies it. 

Redirection to reuse

  • For flushing toilets
  • For watering the plants or garden
  • To wash clothes after being treated
Water is collected on-site and stored in a cistern which is then used throughout the summer
Water is collected on-site and stored in a cistern which is then used throughout the summer

3. Rain gardens

Surface runoff of rainwater is often not given needed consideration while designing a space. 

Rain gardens help temporarily hold rainwater in areas where there is a natural slope. Planting vegetation helps hold the nutrients of the soil while actively preventing surface runoff.

Edinburgh Raingarden by GHT Pty Ltd
Edinburgh Raingarden by GHT Pty Ltd

4. Drip Irrigation

When it comes to maintaining vegetation, it’s easy to overwater them. One of the most effective methods to avoid the wastage of water is drip irrigation. Distributed pipelines help deliver water and nutrients in small quantities throughout the day directly into the roots of the plants.

Drip Irrigation System
Drip Irrigation System

5. Pressure reduction

A water pressure regulator is used to reduce the pressure of water coming into the building through the main water line. This valve brings down the pressure to a safe level so as to not cause any plumbing problems. 

  1.  Some appliances like dishwashers and washing machines have built-in regulators but having them still offers protection to all the fixtures. 
  2. The regulator has a diaphragm that widens or reduces based on the speed of the water. 
  3. It can also be tightened or loosened to regulate the flow.
Water Pressure Regulator
Water Pressure Regulator

6. Plumbing Fixtures

Most of the water use and wastage in the buildings occur in faucets and toilets. With the advancement of technology, smart plumbing fixtures help regulate water supply and wastage.

  • Faucet aerators
  • Shower Regulators
  • Toilet leak detection devices
  • Pressure reducing valves
  • High-efficiency toilets
  • Performance showerheads
  • Recirculating hot water systems
Faucet aerators
Faucet aerators

7. Water treatment system

Water treatment plants remove undesirable components and decontaminate water to be used for drinking or any other desired usage. 

There are two main processes involved in the system

  1. Physical processes such as settling and filtration
  2. Chemical processes such as disinfection and coagulation
  3. Biological processes such as slow sand filtration
Muttenz Water Treatment Plant by Oppenheim Architecture
Muttenz Water Treatment Plant by Oppenheim Architecture

8. Wastewater recycling

Removing contaminants from water to convert it into a usable resource can be done through wastewater recycling. This can be done both on a small scale and large scale. 

  1. Physical Treatment: Solids are removed through skimming, sedimentation or other similar processes. There will be no addition of chemicals to perform this treatment. 
  2. Biological Treatment: Biological processes are followed to break down already existing organic matter in the wastewater. Microorganisms are used in this process. 
  3. Chemical Treatment: Chemicals such as chlorine are used to kill and decompose bacteria existing in the wastewater.
  4. Sludge Treatment: This treatment involves the separation of solid and liquid through the production of residue.   

9. Water catchments

Water catchments or watersheds are places where runoff or moving water flows into. It can later be used for a variety of purposes:

  1. They catch water to be reused or recycled for the building
  2. It can be used as a recreation
  3. It can stock up for irrigation or watering purposes. 
  4. Can be used to encourage habitat for plants and animal species. 
Water catchment that lets rainwater flow to the garden space
Water catchment that lets rainwater flow to the garden space

10. Drought Resistant Landscaping

In regions where the rainfall is sparse, drought-resistant landscaping is done. By planting vegetation that needs little to no moisture to grow, the plants are easy to maintain and can survive for long periods of time without water. 

  1. They don’t require a constant supply of water
  2. They keep up the quality of soil and prevent the occurrence of droughts.
  3. Combine the landscaping with hardscaping elements such as patios and pergolas. This improves the appeal of the space even when there isn’t expansive green ground at sight.
Permeable pavers with water-wise plantings at front garden by Marina Wynton
Permeable pavers with water-wise plantings at the front garden by Marina Wynton

Other water conservation technologies:

  • Soil moisture sensors
  • Rain sensors
  • Rainwater shutoff devices
  • Irrigation controllers
  • Leak detection units and shut off

When designing for maximum water efficiency, the green building has the ability to control one of the most precious resources. Creating the most ideal water system for a building must never be overlooked. 

Choosing methods that enhance the experience of the user and customizing to the personal needs not only makes sure that the building is environmentally friendly, but also enhances the user experience all in all.

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