LE 06 – Rainwater harvesting

Step

Category

Mandatory standards

No. of credits available

3

Land use and ecology

No

3

Aim

To ensure that surface water run-off space is used effectively to minimise water demand.

Assessment Criteria

The following is required to demonstrate compliance:

One to three credits

  1. Credits are awarded based upon the percentage of the total hard surface for the site (roof plus hard-standing) that is designed to allow the harvesting of rainwater for re-use. Credits are awarded based upon the following:
Credits Requirements

One

Between 5% - 25%

Two Between 26% - 50%
Three Greater than 50%
  1. Rainwater collection systems are designed and specified in accordance with the national best practice standard (to ensure both the demand and yield for the building will be considered when sizing the tank)
  2. The collection area is measured in accordance with the national best practice standard.
 

Compliance Notes

Ref

Terms

Description

CN1 

Use of rainwater . See criterion 1

The percentage of collected rainwater must be used to meet (in part) toilet flushing demand and/or washing machines within buildings. Only once demand from these fittings has been satisfied should rainwater be used for irrigation of planting and landscaping demand.

CN2 

National best practice standard. See criteria 2 & 3

Please refer to the country-specific reference sheet in the BREEAM Communities Approved Standards list to locate the appropriate national best practice standard in the country of assessment. Alternatively, please demonstrate applicability as follows:

The minimum requirements as set out in the approved standards list are covered by the proposed documents and are submitted to BRE Global for approval; OR

Where appropriate alternative standards do not exist for a country, the design team should demonstrate compliance with the UK or European standards as listed in each relevant country reference sheet.

Evidence

Criteria No.Final Assessment

1

Design specifications and/or a copy of the masterplan or relevant site plans.

2

Calculations and written confirmation from the developer.

Additional Information

This issue does not conflict with other assessment issues encouraging the use of SuDS such as green roofs (for example LE 03 – Water pollution and SE 13 – Flood risk management). With careful design it is possible to implement a design solution which includes the use of rainwater harvesting and a green roof. Whilst this is likely to require more specialist equipment, and appropriate advice would need to be sought, this issue does not prevent the use of green roofs with rainwater harvesting systems.

Concept Link IconSee Also


BREEAM Communities technical manual
Reference: SD202 – Issue: 1.2
Date: 14/08/2017
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