Building standards guidance - Section 3.3 Flooding and Groundwater: consultation on proposed updates

Introduction

Purpose

The purpose of this review is to consider updates to the guidance within Section 3.3 (Flooding and groundwater) of the Building Standards Technical Handbooks with a particular focus on property flood resilience (PFR) for new buildings and new building work that is being undertaken in areas identified as being at risk of flooding.

PFR is a combination of flood resistant and recoverable construction techniques and products that, when designed into a building, can reduce damage and speed up recovery should a flooding event occur.

The intent of the proposed updates is to provide more guidance and information to enable designers to achieve compliance with Mandatory Standard 3.3 and to support building standards verifiers in their assessment of projects against the requirements of the standard.

Reason for proposed updates to guidance

In 2018, the Scottish Environment Protection Agency estimated that 1 in 11 homes (around 229,000) across Scotland were at risk of flooding from rivers, surface water and the sea, with projections indicating this would increase to 1 in 9 homes considering a 2080’s future climate change scenario^[1].

Whilst there has been action to help alleviate the effects of flooding through measures such as alerts, flood schemes and sustainable drainage schemes (SuDS), in Scotland the responsibility for protecting property from flooding rests with the owner.

The 2018-19 Programme for Government included a commitment to develop a property flood resilience action plan and in December 2018, the Scottish Government published the ‘Flood resilient properties: framework for Scotland’^[2]. This established the Property Flood Resilience Delivery Group (PFRDG), which was tasked with preparing and delivering an action plan to help property owners take action to make their properties more resilient against the impacts of flooding.

As a member of the PFRDG, the Building Standards Division (BSD) has played an important role in considering how PFR measures may be incorporated into new and existing homes.

In November 2019, the PFRDG published ‘Living with flooding: an action plan for delivering property flood resilience in Scotland’^[3].

One of the key objectives of the action plan is influencing policy and providing clear guidance on PFR to industry, property owners and occupiers. In this regard, BSD officials committed to identify opportunities to strengthen the PFR guidance provided in Section 3.3 Flooding and groundwater of the Building Standards Technical Handbooks.

Engagement with stakeholders was undertaken through the convening of a Section 3.3 Flooding and groundwater working group, which had 8 quarterly meetings between June 2022 and September 2024. Members’ expertise and knowledge in flooding and property flood resilience has informed the drafting of revised guidance, considering all current industry guidance and the building standards advice previously provided in Planning Advice Note (PAN) 69 (now superseded).

The Scottish building standards system

The building standards system in Scotland is established by The Building (Scotland) Act 2003 (The 2003 Act). The purpose of the building standards system is to protect the public interest. The system regulates building work on new and existing buildings, to provide buildings that meet reasonable standards which:

• secure the health, safety, welfare and convenience of persons in or about buildings and of others who may be affected by buildings or matters connected with buildings,
• further the conservation of fuel and power, and
• further the achievement of sustainable development.

The building standards system is pre-emptive and is designed to check that proposals meet building regulations. The main principles of the system are that a building warrant must be obtained from a verifier before work commences on site and a completion certificate is accepted by a verifier if, after undertaking reasonable inquiry, they are satisfied the building work meets the building regulations, prior to the building being occupied. The thirty-two local authorities in Scotland are appointed by Scottish Ministers as verifiers to administer the building standards system in their geographical areas. Responsibility for compliance with the building regulations lies with the “relevant person” as the party instructing building work and, ultimately, with the building owner.

Requirements applicable to building work are set through Building Regulations as a set of mandatory functional standards. These are simple statements on what outcomes must be achieved when undertaking building work. These standards are supported by a body of guidance set out in Domestic and Non-domestic Technical Handbooks.

This published guidance assists by defining the scope of action expected under each standard by providing one or more examples of how compliance with the standard can be achieved. Noting that the standards can also be met through solutions not included in published guidance.

The BSD is part of the Scottish Government Directorate for Housing. Our purpose is to provide and maintain a robust legislative framework to ensure that the building standards system in Scotland protects the public interest.

The BSD prepares and updates building standards legislation and guidance documents, conducting any necessary research and consults on changes as The 2003 Act requires. We also work in partnership with Local Authority verifiers in the delivery of the system and contribute to wider policy objectives of government on issues such as energy efficiency, climate change and building safety.

Scottish Government flood resilience strategy

Scotland’s National Flood Resilience Strategy^[4], published in December 2024, sets out a vision for a flood resilient Scotland through to 2045 and beyond.

This Strategy, part of our Scottish National Adaptation Plan 2024-2029^[5] (SNAP3), is in direct response to the climate emergency and the imperative to address the challenges that we face.

Focusing on building community flood resilience and resilient placemaking, it puts people at the heart of the process and supports an increase in the range and rate of delivery of actions both to manage our flood exposure, and to reduce the impacts of flooding when it does occur.

The Strategy supports a flood resilient places approach, recognising that reducing the impacts of flooding is as much about the design of our places as it is about the design of specific flood actions.

Scope of this consultation

This consultation sets out proposed updates to guidance in Section 3.3 Flooding and groundwater of the Building Standards Technical Handbooks, including the introduction of a new Annex 3.B Building Standards Flood Guide.

These proposals are not intended to require building warrant applicants to do more than is currently required to meet Mandatory Standard 3.3. The intent is to provide designers and verifiers with more knowledge and information on how to meet the standard where a flood risk has been identified and planning permission has been approved with relevant conditions attached.

The consultation seeks your views on the proposed updates.

Consultation documents

This consultation comprises of the following elements:

• Consultation proposals and questions (this document, published in html and pdf)
• The online consultation form for your response.

A Respondent Information Form and list of consultation questions is also provided in Word format on the consultation webpage for consultees who are not able to provide a consultation response online.

Responding to this consultation

This consultation runs for 12 weeks from 11 July 2025. We are inviting responses to this consultation by 03 October 2025.

Please respond to this consultation using the Scottish Government’s consultation hub, Citizen Space. You can save and return to your responses while the consultation is still open. Please ensure that consultation responses are submitted by the closing date of 03 October 2025. If you use Citizen Space to respond, you will receive a copy of your response via email.

If you are unable to respond via Citizen Space, please complete the Respondent Information Form and the consultation questionnaire available on the consultation webpage and return to:

Via email: buildingstandards@gov.scot

Via post: