Approved Document G: A Guide to Regulations for Sanitation

Learning Outcomes

By the end of this article, you should:

– Have a thorough understanding of the requirements in Approved Document G and related Building Regulations

• Apply the sanitation, hot water and water efficiency specifications correctly.
• Know the standards for providing sanitary conveniences, bathrooms and accessible facilities.
• Understand the safe design of hot and cold water systems and wastewater drainage.  
• Be familiar with water efficiency targets and compliance methods.  
• Recognise common issues and how to achieve compliance reliably.

Introduction

To protect public health, adequate, hygienic and efficient sanitation and water systems are essential in buildings. Approved Document G provides full guidance on meeting the relevant requirements of the Building Regulations for England and Wales.

This comprehensive guide covers the key specifications in Parts G, H and L related to sanitation, hot water safety, drainage and water efficiency. It supports compliance for residential and non-residential buildings. Topics covered include:

• Calculating sufficient sanitary provisions
• Technical design standards for water and drainage systems  
• Avoiding contamination and microbial risks
• Specifying water-efficient fittings, appliances and meters
• Methodology to demonstrate compliance
• Recommendations for avoiding common pitfalls

Understanding and applying Approved Document G enables the development of safe, comfortable and sustainable buildings.

Scope and Application of Approved Document G

Approved Document G provides practical guidance on meeting regulations G1, G2, G3, G5, G6, H1, H2, H3 and L1, L2 in Schedule 1 of the Building Regulations 2010.

It contains specifications related to:

• Part G – Sanitary conveniences, washing facilities, bathrooms
• Part H – Cold water supply, hot water supply and systems, wastewater drainage
• Part L – Conservation of water through efficiency measures

The requirements apply to domestic and non-domestic buildings. By meeting the standards set out, suitable sanitation provisions and safe water services will be provided, supporting public health and water conservation.

Part G Standards for Sanitary Conveniences and Washing Facilities

Part G lays down standards for the appropriate provision of sanitary conveniences, washing facilities and bathrooms in buildings. Key requirements include:

Sufficient Sanitary Conveniences

• An adequate number of sanitary conveniences must be provided for the occupants
• The number required depends on building type and occupancy
• Separate facilities must be provided for males and females in some buildings

Accessible Sanitary Conveniences

• Suitable accessible sanitary conveniences required in buildings like shops, restaurants, offices
• Must meet technical specifications for accessible WC facilities (door widths, grab rails, etc.)

Appropriate Bathrooms and Washing Facilities

• Bathrooms must have minimum floor area and layout for safe use.
• Adequate mechanical extract ventilation is required.
• Cold water supply must be provided to sanitary fittings.
• Suitable changing and showering facilities are needed in some buildings.  

Calculating Sanitary Provision Requirements

The number of sanitary conveniences needed is determined based on:

• Building type – e.g. dwelling, restaurant, office, surgery.
• Number and gender of occupants – based on building usage.
• Accessibility – the proportion of facilities suitable for disabled people.

Tables are provided in Approved Document G for quick reference but calculations may be required for some building types.

Key Requirements Under Part H  

Part H specifies requirements to ensure the safe and appropriate provision of water services and adequate wastewater drainage in buildings. Key requirements include:

Water Supply

• Buildings must be provided with a potable cold water supply
• Appropriate storage capacities and temperatures at outlets
• Adequate water pressure and flow rates for the intended use
• Suitable hot water provision for sanitary needs

Water Quality

• Water supplies must be wholesome for domestic purposes
• Treatment likely required for rainwater or greywater systems
• Avoid contamination from pipework, storage tanks, stagnation

Water Systems Design

• Pipes and components must be appropriately sized.
• Minimize dead legs to avoid water stagnation.
• Take measures to prevent scalding risks.
• Provide suitable cold water supply to sanitary fittings.  

Wastewater Drainage

• Safe foul water drainage via suitable pipes to a collection point.
• Adequate ventilation to prevent foul air from entering buildings.
• Rainwater drainage to suitable outfall (drain/soakaway).

Specifying Low Flush Sanitary Fittings

To help meet Part L water efficiency targets, the maximum flush volumes of WCs and urinals must be limited:

Toilets

• Single flush WC – 4.5 litres
• Dual flush toilets – up to 4/2.6 litres

Urinals

• Urinals – 1.5 litres per bowl/per hour
• Waterless urinals – 0 litres

Selecting sanitaryware with low flush volumes helps reduce water use while maintaining performance.

Key Considerations for Drainage Systems

The drainage system must safely convey wastewater and rainwater from the building. Key specifications include:

• Pipe diameters – Minimum diameters specified based on load
• Gradient – Minimum 1:80 slope for horizontal drainage runs
• Ventilation – Adequate ventilation terminals for drainage runs
• Capacity – Drainage capacity must suit the total building load  

Following the technical specifications in Part H ensures drainage is safe, and effective and prevents foul air ingress.

Water Efficiency Requirements Under Part L

Part L of the Building Regulations considers the critical role of conserving potable water supplies in buildings. It emphasizes the need to implement effective measures to promote water efficiency. Here are the core requirements:

Water Efficiency Targets

Part L stipulates the need for setting specific water consumption levels as targets for various types of buildings. These include residential dwellings and commercial and public facilities like offices, schools, and hotels. The aim is to ensure that water use in these buildings is regulated and kept within permissible limits to avoid wastage.

Specifying Efficient Fittings

Part L outlines the need to install water-efficient fittings to complement the water efficiency targets. It prescribes the maximum flow rates for sanitary fittings such as taps, showers, and water closets (WCs). By dictating the flow rates of these fittings, it ensures that water usage is optimized without compromising on the functionality and comfort of the users.

Monitoring Water Use

To effectively manage water usage, Part L underscores the importance of tracking and monitoring water consumption. This is achieved by mandating the installation of water meters and other water monitoring systems in buildings. These systems help keep a tab on water consumption, thereby providing valuable insights to identify areas of potential wastage and implement suitable corrective measures.

Leak Detection

The efficiency of water usage is not only about managing consumption but also about preventing wastage due to leaks and overflows. To this end, Part L requires integrating leak detection systems in the plumbing infrastructure of buildings. These systems play a vital role in quickly identifying any wastage due to leaks or overflows, thereby facilitating immediate repair and preventing unnecessary water loss.

Achieving Compliance with Part L: A Detailed Approach

To validate compliance with the water efficiency requirements outlined in Part L of the Building Regulations, you have two main routes:

• Utilize the Water Efficiency Calculator tools: These tools offer a complete set of fit-out specifications designed to aid you in meeting the target consumption levels. Adhering to these specifications ensures your project meets the prescribed water efficiency standards.
• Perform detailed water consumption calculations: This alternative involves meticulous water consumption calculations using the relevant and accepted methodology. This method demands a precise understanding of water usage patterns and efficient management systems.

Remember, implementing water-efficient fittings and appliances is instrumental in meeting the target consumption levels set out by Part L.

Common Compliance Issues: Avoiding the Pitfalls

There are several common pitfalls encountered when attempting to comply with Approved Document G. Recognizing these in advance can help mitigate potential problems:

• An insufficient number of sanitary conveniences: A common issue is not providing enough sanitary facilities about building occupancy and use. You must ensure that the number and type of sanitary conveniences align with the estimated usage.
• Undersized drainage runs: This leads to blockages, disrupting normal functioning. Always ensure that the size of the drainage system corresponds with the expected volume of waste.
• Non-compliant cold water storage tanks: Tanks not meeting temperature requirements can lead to health risks. Strictly adhere to guidelines to avoid waterborne diseases.
• Absence of planned maintenance and testing regime: A maintenance and testing schedule is crucial to ensure the efficient operation of water and sanitation systems.
• Failure to commission water systems before completion: Water systems need to be fully operational and tested prior to the completion of the project.

These common issues can be avoided by employing careful design strategies, adhering to the guidance provided in this document, and collaborating with experienced contractors.

Achieving Compliance: Best Practice Recommendations

Following are key recommendations, based on industry best practices, for reliably complying with Approved Document G:

• Check sanitary facility provisions: Regularly cross-check your provision of sanitary facilities against the requirements outlined in Part G.
• Design with optimization and safety in mind: Prioritize designing systems with a focus on safety and optimization to ensure efficiency and the well-being of occupants.
• Specify compliant low flush sanitaryware: Use sanitary ware that adheres to the low flush guidelines as this aids in water conservation.
• Ensure adequate sizing of drainage runs: Design and install drainage systems that can handle the expected volume of waste to avoid blockages.
• Install required water meters and leak detection systems: These are vital tools for monitoring water usage and identifying potential problems early.
• Complete commissioning tests before sign-off: Conducting tests before completion helps ensure that the installed systems work as intended and comply with the regulations.

Conclusion: Ensuring Compliance for Better Outcomes

Guaranteeing safe and efficient sanitation and water services is crucial for any building. This guide provides in-depth information on using Approved Document G to comply with sanitation, hot water safety, and water efficiency requirements as outlined in the Building Regulations.

Understanding and correctly applying the outlined standards is key to ensuring public health protection, occupant safety, and adequate water conservation. Use this guide as a reference throughout your project and don’t hesitate to reach out to us for further support and clarification.

FAQ Approved Document G