In Brief: Current Legislation and Targets

Provided by Ewan Willars: Head of Policy, RIBA


The UK now has a number of legally binding national targets for reducing greenhouse gas emissions. It was the first country in the world to create a national legal framework for tackling climate change, identified emission reduction targets for 2020 (a reduction of 34 percent) and for 2050 (a reduction of at least 80 percent), and introduced five-yearly carbon budgets to help ensure those targets are met.

The means of ensuring that buildings play their part in achieving these national targets is primarily through the building regulations, which set clear performance minima, and which co-exist alongside other standards and targets, such as the Code for Sustainable Homes, which have some official standing but relate mainly to best practice which goes beyond the legal requirements.

The Government’s overall strategy involves both encouraging organisations to reduce their emissions and embrace opportunities through setting regulations, establishing market-based mechanisms, providing incentives and ensuring the provision of information, advice and support. It is hoped that this will help to stimulate the development of low carbon solutions and services and promote their uptake throughout the UK.

Climate Change Act 2008

The Climate Change Act introduced the world’s first long-term legally binding framework to tackle the dangers of climate change. Two key aims of the Act were to improve carbon management, helping the transition towards a low-carbon economy in the UK; and to demonstrate UK leadership internationally, signalling that we are committed to taking our share of responsibility for reducing global emissions.

Some of the key provisions of the Act were:

  • A legally binding target of at least an 80 percent cut in greenhouse gas emissions by 2050, to be achieved through action in the UK and abroad. Also a reduction in emissions of at least 34 percent by 2020. Both these targets are against a 1990 baseline.
  • A carbon budgeting system which caps emissions over five-year periods, with three budgets set at a time, to help us stay on track for our 2050 target. The Government must report to Parliament its policies and proposals to meet the budgets.
  • The creation of the Committee on Climate Change (CCC) - a new independent, expert body to advise the Government on the level of carbon budgets and on where cost-effective savings can be made.
  • A requirement for the Government to report at least every five years on the risks to the UK of climate change, and to publish a programme setting out how these will be addressed. The Act also introduces powers for Government to require public bodies and statutory undertakers to carry out their own risk assessment and make plans to address those risks.
  • An Adaptation Sub-Committee of the Committee on Climate Change, providing advice to, and scrutiny of, the Government's adaptation work.
  • A new requirement for annual publication of a report on the efficiency and sustainability of the Government estate.

Building regulations

Building regulations are statutory instruments that seek to ensure that the policies set out in the relevant legislation are carried out. Building regulations approval is required for most building work in the UK. Building regulations that apply across England and Wales are set out in the Building Act 1984 while those that apply across Scotland are set out in the Building (Scotland) Act 2003. The UK Government is responsible for the relevant legislation and administration in England and Wales, the Scottish Government is responsible for the issue in Scotland, and the Northern Ireland Executive has responsibility within its jurisdiction. The regulations apply to most new buildings and many alterations of existing buildings, whether domestic, commercial or industrial.

Changes are now planned as part of a steady escalation of the building regulations enabling all new homes to be zero carbon from 2016 and considering similar approach for new non-domestic buildings from 2019. The plans for future updates of the Building Regulations Part L include reducing the carbon dioxide emissions permitted from energy use in new homes by 25% in 2010 and 60% in 2013 (based on 2006 standards). By 2016, all new housing is expected to be ‘net zero carbon’. These improvements are equivalent to Levels 3, 4 and 6 of the Code for Sustainable Homes (see below). 

Part L of the Building Regulations controls:

  • insulation requirements
  • limitation of openings of the building fabric (door and window apertures)
  • solar heating and heat gains to structures
  • heating
  • mechanical ventilation and air conditioning systems
  • lighting efficiency
  • space heating controls
  • air permeability
  • solar emission
  • the certification, testing and commissioning of heating and ventilation systems
  • requirements for energy meters
  • air permeability is measured by air tightness testing for new dwellings (based on a sampling regime), all new buildings other than dwellings and large extensions to buildings other than dwellings.


Part L also sets out the requirements for SAP (Standard Assessment Procedure) calculations and Carbon Emission Targets for dwellings.

Approved Document L1 is supported by a set of 'robust' construction details, now known as 'Accredited Construction Details' which focus on way of limiting air leakage and thermal bridging in construction. By using these tried and tested details, expensive on-site testing can be avoided.

Part L2A presents five criteria for demonstrating compliance for new non-domestic buildings, and Part L2B provides guidance about the requirements that apply when work is carried out on existing non-domestic buildings.

The Code for Sustainable Homes

The Code for Sustainable Homes is a standard for new dwellings that sets levels of performance for a range of environmental impacts. While for privately developed homes the Code is not a formal legal requirement, it increasingly underpins the Building Regulations in England and Wales, and will provide the basis for future changes to the regulations.

The Code for Sustainable Homes deals with more than energy use and carbon dioxide emissions. There are nine performance categories:

  • Energy use and carbon dioxide emissions
  • Water
  • Materials
  • Surface water run-off
  • Waste
  • Pollution
  • Health and well-being
  • Management
  • Ecology

The Code incorporated six levels for compliance, each of which has mandatory carbon dioxide emissions standards.

Code level

Reduction in carbon dioxide emissions compared with

Building Regulations, Part L (2006)












‘Net Zero Carbon’

For Code Levels 1-5, the carbon dioxide emissions reductions are assessed by means of the Target Emissions Rate (TER) incorporated in Building Regulations Part L1A. The TER deals only with emissions related to energy use for heating, hot water and internal lighting. Level 6 of the Code – net zero carbon – covers all energy use including cooking and the use of electrical appliances.

Since April 2007, all new publicly-funded housing has been required to meet Level 3 of the Code, with new rules likely to enforce Code Level 4 for all housing funded through the Homes and Communities Agency later in 2010. Some local planning authorities and development agencies) are using the Code as the basis for environmental standards for new dwellings in their areas.

The Government made assessment of new dwellings against the Code mandatory from May 2008.   Any new dwelling that is not assessed for compliance with the Code must have a ‘null rating’ certificate.

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