Water conservation — and conservation as a whole — has become more critical in recent years. It has become vital to develop more sustainable living habits and construction practices for the sake of the planet. Here’s how to implement water conservation into building design.

Understanding How Buildings Use Water

To understand how to conserve water, we first need to identify how buildings use it. Here’s what the average day inside an American household looks like:

• The average home uses 300 gallons per day (GPD)

• 70% of a home’s water consumption occurs indoors

• Bathtubs, toilets, washing machines, showers and dishwashers use the most water

• The average person flushes a toilet six to eight times per day (18 to 24 gallons of water)

• Leaks, dripping faucets, running toilets and sprinkler systems contribute to excessive water usage

If you thought those numbers sounded wasteful, the average commercial building in America doesn’t do any better:

• An office building with 200 employees uses about 3,000 GPD

• 1,230 GPD is used for domestic needs

• 810 GPD is used for cooling and heating

• 600 GPD is used for landscaping

• 360 GPD accounts for other water needs

• The average employee uses 15 GPD

Based on these trends, the clear frontrunners for water consumption are domestic needs, utilities and landscaping. We will focus on building designs ideas that optimize water usage in these three areas.

Natural Solutions

Natural energy-efficient solutions like rainwater harvesting work best for domestic needs, especially in buildings with large roofs. Rainwater has many uses, but it’s the most beneficial for household purposes because it’s cleaner and has fewer chemicals than tap water. Here are the best systems that can work in domestic and commercial buildings:

• Direct pump: A pump runs from the roof to the building’s underground tank or utility room.

• Indirect pump: A pressurized booster pump sends rainwater to a collection tank at any building level.

• Water butt: A water butt or barrel collects rainwater from gutter and drainage pipes. 

• Indirect gravity: Water flows into a header tank at the building’s highest level, which sends water through connected pipes to other areas of the building.

• Gravity only: Tanks sit below the gutters and drains, collect rainwater and feed it to the utilities below through gravity alone.

• Inground storage: Insulated underground tanks collect water and send it to the building’s utilities via an electric pump. This method is best for regions that get a lot of rainfall in one season.

With one or several of these systems in place, rainwater can address most of a building’s domestic needs without excessively running tap water and hemorrhaging resources. The limited supply forces occupants to be responsible with their usage, but it also rewards them with fresh, chemical-free water.

Grey water is the better natural solution for utilities. A grey water reclamation system recycles untreated water that hasn’t reached the sewage system and sends it back through a building to reuse. The system doesn’t completely filter the water but makes it sanitary enough for toilets and outdoor purposes.

Overindulgent flushing is a major problem in domestic and commercial buildings, so recycled grey water can significantly reduce daily usage. It also provides an alternative source for hoses, sprinkler systems and other landscaping tools.

Efficient Appliances

Natural solutions have their roles, but they don’t address modern infrastructure problems like leaks and faulty plumbing. You need to implement proactive design features that prevent these issues before they occur. Luckily, modern smart home technology has given rise to several smart plumbing fixtures and appliances that can do the trick:

• Low-flow plumbing fixtures: New toilets, showerheads, faucets and flush valves are designed to limit their water usage, saving up to 700 gallons a year.

• Hot water recirculator: This appliance provides instantaneous hot water. You no longer need to wait for water to heat up in sinks and showers, potentially saving hundreds of gallons per month.

• Smart water assistant: Attach this unique smart home device to your sink’s pipe system. It detects leaks and provides valuable data about water usage across the building’s utilities, allowing you to see which areas need improvement.

• Rain sensor: This outdoor device detects precipitation and shuts off water to the irrigation system, letting rainwater do the work instead.

When toilets, sinks, washing machines and other appliances operate with minimal water usage, the conserved amount quickly multiplies. You can save thousands of gallons — and dollars — a year by installing these innovative fixtures.

Outdoor Optimization

A building’s outdoor surroundings play a more prominent role in water conservation than we realize. The right landscaping setup means your building’s irrigation system won’t have to use nearly as much water, and the environment can rely on natural processes to thrive. Here are some simple landscaping design ideas to reduce water usage:

• Limit the turf area. Less grass means less daily watering and fewer resources spent on lawn maintenance.

• Add water-retaining mulch and other organic matter to the soil. Better soil means less frequent maintenance.

• Plant rain gardens in low-lying runoff areas around the property. These gardens make the surrounding landscape healthier and more beautiful.

• Only use native and drought-resistant plants. If a drought occurs, you don’t need to use more water to keep your vegetation alive.

• Group plants according to their water and sunlight requirements. This design will consolidate your landscaping practices and help save water.

These small efforts combined with natural solutions will bring water usage for landscaping down to an absolute minimum, affording you more flexibility with indoor utilities.

Design Your Water-Efficient Building

A conservative building reduces water consumption in three essential areas: domestic needs, indoor utilities and outdoor landscaping. Each has natural and artificial solutions, from rainwater collection to smart appliances to simple gardening techniques. Implement these features into your next design to create a proper water-efficient building.

Propel Studio is committed to designing low energy Residential and Commercial buildings. For more information about our Residential design work, please visit this page. For more information about our Commercial design work, please visit this page.