Building standards - energy and environmental compliance handbook: consultation proposals

Energy and Environmental Requirements

Energy and environmental standards

Since the introduction of national building regulations to Scotland in 1964, there have been energy standards, in one form or another. Initially these only applied to the external fabric of certain residential buildings and were minimal in nature. Later, they evolved to take account of commercial and industrial non-domestic buildings and to address the energy efficiency of those building services essential to provide comfort to occupiers of buildings.

Prior to 2000, reviews of energy standards were less frequent, with the outcome of such reviews resulting in modest standards that kept pace with change, but which could be comfortably achieved by all aspects of industry. An impact assessment carried out on subsequent changes over this era would show a cost-benefit for modest improvements which would pay back quickly through reduction in the occupier’s energy bills.

Following the introduction of The 2003 Act and our current system of building standards in May 2005, energy standards within section 6 of the Building Standards Technical Handbooks were reviewed and improved in 2007, 2010, 2015 and most recently in 2023. For new buildings, 2007 saw the introduction of a single means of demonstrating compliance based on calculated carbon dioxide emission targets, using the Standard Assessment Procedure (SAP) for dwellings and the Simplified Building Energy Model (SBEM) (or equivalent) for non-domestic buildings.

Each review introduced further staged improvement to energy standards and related changes on topics such as ventilation. It is assessed that emissions arising from energy use in new buildings constructed to the 2023 standards are, on aggregate, around 32% lower for new homes and 20% lower for new non-domestic buildings, compared to the previous 2015 standards and more than 80% lower than standards in force in 1990, the baseline reporting year for CO₂ emissions.

In May 2022, Alex Rowley MSP put forward a draft proposal for a Proposed Building Environmental Standards (Scotland) Bill. This was confirmed in a final proposal of 18 November 2022 for “a Bill to introduce new minimum environmental design standards for all new-build housing to meet a Scottish equivalent to the Passivhaus standard, in order to improve energy efficiency and thermal performance”.

In December 2022, Ministers committed to give effect to the Members’ Bill to deliver ‘a Scottish equivalent to the Passivhaus standard’ with a focus on two outcomes:

• Improvements to the setting of energy and environmental (ventilation) performance standards for new buildings, leading to lower energy demand (and reduced running costs) and a healthy indoor environment; and
• Improvements to the design and construction process to give greater assurance that compliance, and therefore the performance sought, is delivered in practice.

The Building (Procedure) (Scotland) Amendment Regulations 2024, refers specifically to the following energy and environmental standards:

Section 3 – Environment:

• Heating (Standard 3.13)
• Ventilation (Standard 3.14)
• Overheating Risk (Standard 3.28)

Section 6 – Energy:

• Energy Demand (Standard 6.1)
• Building Insulation Envelope (Standard 6.2)
• Heating System (Standard 6.3)
• Insulation of Pipes, Ducts & Vessels (Standard 6.4)
• Artificial & Display Lighting (Standard 6.5)
• Mechanical Ventilation and Air Conditioning (Standard 6.6)
• Commissioning Building Services (Standard 6.7)
• Metering (Standard 6.10)

Section 7 – Sustainability:

• Statement of Sustainability (Standard 7.1)
• Electric Vehicle Charging (Standard 7.2)

Clauses from the Technical Handbooks are referenced in this handbook and schedules A and B. Always refer to the current applicable Standards and Technical Handbooks available from www.gov.scot/collections/building-standards/

Key energy and environmental considerations

Measures fundamental to energy and environmental compliance and assurance include ensuring air tightness, using high-performance windows, doors and insulation products, minimising thermal bridging, providing ventilation that preserves indoor air quality with minimal heat loss, optimising heating, hot-water and power efficiency, and preventing overheating during warm periods.

Design Statement requirements

The Design Statement should include design information to demonstrate that the energy & environmental design presented as part of the building warrant application is achieving the requirements of the relevant mandatory standards.

Schedules A (Domestic) & B (Non-Domestic) of the handbook provide practical guidance on the information to be collated for the relevant mandatory standards respectively.

Each relevant mandatory standard must be addressed in the Design Statement, but supporting information may be collated once and referenced accordingly.

Supporting information should be provided to show that each part of the standard has been considered in the building warrant design by referencing submitted drawings / specification / layout / schedules as appropriate.

Key roles and responsibilities and risk management should also be considered at the design stage, which should be included as part of the Design Statement.

Design information to be gathered and managed

Building and product information, for example:

• Design drawings (floor plans, elevations, and sections, etc)
• Material specifications and product datasheets (insulation products, window and door performance, etc)
• Performance calculations (U-Values, Psi Values, etc)
• Energy modelling results

System specifications, for example:

• Heating system design and efficiency
• Hot water system design and efficiency
• Ventilation system design

Construction Statement requirements

The Construction Statement should include evidence during construction as well as ‘as built’ records to demonstrate that the completed building design is achieving the requirements of the relevant energy & environmental mandatory standards.

Schedules A (Domestic) & B (Non-Domestic) of the handbook provide practical guidance on the evidence to be collated for each mandatory standard respectively.

Supporting evidence provided should be cross referenced to the Design Statement as part of the completion submission. Evidence will generally include product and delivery information, as well as photographic evidence of building elements, as appropriate.

Photographs should clearly show installation location and arrangement, related construction details, legible readings, product labels and model numbers, visible measurements (e.g. using a tape measure or ruler) and be taken before covering critical elements. At least 2–5 photos per building element or system depending on complexity, should be provided.

Roles and responsibilities and risk management should also be reconsidered during the planning and build phases of construction, which should be updated and included as part of the Construction Statement.

Construction evidence to be gathered and managed

• Delivery notes for materials, products, equipment, etc
• Photos of building elements and system installations at key stages
• Product labels showing type, specification, etc
• Testing results, namely air tightness, as required by mandatory standards, etc
• Commissioning certificates

Managing changes during construction

Any changes to the design of the building, or associated specification of elements, during construction, must be:

• Submitted for assessment through an amendment to building warrant application
• Documented in the Construction Statement
• Tested to confirm they still meet standards
• Agreed with the Verifier and the Approved Certifier of Design. The amendment to building warrant procedure must also be followed.

Changes typically not requiring an amendment to building warrant are substitutions that maintain or improve performance associated with the relevant Energy or Environmental Mandatory Standard(s).

Changes typically requiring an amendment to building warrant are substitutions that affect energy or environmental performance and associated aspects of the building.

The Verifier will confirm if an amendment to building warrant is required for any changes.

Resources

Specialist support:

• Certifiers of Design (Energy)
• Energy consultants
• Testing specialists
• Commissioning specialists
• Building Performance specialists
• Third Party Certifiers

Verifier / Building Standards Team:

Your local authority building standards department

Building Standards Division:

Scottish Government guidance and technical handbooks available here

Building Standards Hub:

Scottish Building Standards Hub | SBSH

Compliance Plan Approach:

Compliance Plan Approach Workstream

Certification of Design:

Building Standards Certification Handbook

Building Services Compliance Guide:

Domestic Building Services Compliance Guide

Further sources:

• CIBSE Guidance Documents (TM23, Guide B, etc.)
• Passivhaus Trust (Guidance & Learning Hub, etc.)
• Product Certification Schemes (BBA, BM TRADA, etc.)