Green Deal

Jargon Buster
What does it all mean?

Affordable Warmth Obligation 

Free heating and hot water saving measures, insulation, glazing and microgeneration technologies (except Solar PV) to low income and vulnerable households under the Energy Company Obligation (ECO).


The prevention of leakage of air through gaps and cracks in through the internal spaces and external envelope of a building. 

Approved Document L

If you are working on an existing dwelling or converting a building into a dwelling you have to show that you have complied with the requirements contained in ADL1B. Energy efficiency measures are now required under ADL1B when an existing dwelling (or part of a dwelling) is subject to a variety of refurbishment and retrofit measures including improving the ‘thermal fabric' as well as improving, or even replacing windows, lighting and boilers.

Cavity Wall Insulation

The cavity must be at least 50 mm wide before being injected with insulation. All Cavity Wall Insulation (CWI) systems are approved by the British Board of Agreement (BBA) and British Standards Institution (BSI).

Carbon Emission Reduction Target (CERT)

This is a Government initiative requiring all domestic energy suppliers, with a customer base in excess of 250,000, to make savings in the amount of CO2 emitted by householders. Soon to be replaced by the Energy Company Obligation (ECO).

Carbon Saving Obligation

Funding to insulate solid-walled properties (internal and external wall insulation) and those with ‘hard-to-treat’ cavity walls.

Communities Obligation for Carbon Saving

Free insulation and glazing measures for people living in the lower 15 per cent of the UK’s most disadvantaged areas. It is expected that this section of Energy Company Obligation will be a particular advantage in the social housing sector.

Dwelling Emission Rate (DER)

A measure of carbon dioxide emissions arising from energy use in homes calculated by SAP (Standard Assessment Procedure).

Department for Energy and Climate Change (DECC)

The Government department with the responsibility of progressing the Green Deal and creating policy for the energy efficient refurbishment of the UK's buildings.

Energy Efficiency Rating (EER)

A measurement of the overall energy efficiency of a dwelling on an A to G scale, ranging from 1 to 100 (the higher the number, the higher the energy efficiency).

Energy Company Obligation (ECO)

ECO will take over from the existing obligations of Carbon Emissions Reduction Target (CERT). These existing obligations are due to end in December 2012 and the ECO will take over in addressing energy efficiency in the domestic sector. This will see the energy companies spend about £1.3 billion a year for the next 10 years on subsidising home energy improvements. ECO will focus on providing energy efficiency measures to low income consumers and those living in 'hard to treat' properties, such as period homes. Social housing tenants are not eligible for ECO.

Energy Performance Certificate (EPC)

EPCs are documents which provide information on the energy efficiency of a building and recommendations for improvement. The EPC is a requirement of the European Directive on the Energy Performance of Buildings (EPBD). Under Article 7 of the Directive, any building which is sold, rented out or constructed must have an EPC. This must be issued by a qualified and accredited assessor in an independent manner and in the UK is issued by an accredited Domestic Energy Assessor. The rating measures the energy efficiency of your home using a grade from ‘A’ to ‘G’. An ‘A’ rating is the most efficient, while ‘G’ is the least efficient.

External Wall Insulation (EWI)

External wall insulation involves fixing a layer of insulation material to the wall, then covering it with a special type of render or cladding. The finish can be smooth, textured, painted, tiled, paneled, pebble-dashed, or finished with brick slips

Golden Rule

To be eligible for the Green Deal  the proposed energy efficiency improvement measure will need to meet the 'Golden Rule'  the expected saving from the improvement measure(s) must be equal to or greater than the cost of the measure.  

In most cases, repayment levels will be based on heating bills for the property or the typical energy bills of a similar property. The Green Deal has been designed to try to save the customer at least as much money as they will have to repay.

Green Deal Advice Report

This is produced by a Green Deal advisor and consists of an EPC and occupancy assessment.

Green Deal Advisor

Green Deal Advisors (GDAs) are required for both the domestic and commercial sectors, tasked with carrying out assessments on properties in order to identify and promote how owners can reduce energy usage through alterations to their buildings. This encompasses all areas; from insulation and renewable technology installation.

Only a certificated Green Deal Advisor can produce a Green Deal Advice Report, recommendations and provide related advice on the Green Deal. A Green Deal Advisor must hold a qualification that meets the standard required by the relevant National Occupational Standards and syllabus and be a registered member of a certification body.

Green Deal Approved Mark

The Green Deal Approved Mark will be a prerequisite for any Green Deal adviser or installer. They will have to display this mark to demonstrate that they comply with the relevant requirements and will play a similar role to existing marks such as Gas Safe and Trustmark.

Green Deal Code of Practice

A document setting out the criteria that advisors, installers, providers and products and systems must adhere to in order to be allowed to operate under the Green Deal. To deliver any service under the Green Deal you need to meet its Code of Practice, which will then entitle you to carry the Green Deal quality mark. For installers you need to be assessed against the competences specified and for advisors you need to have a qualification. The Code of Practice is designed to ensure that all Green Deal participants operate fairly, transparently and effectively so that consumers can be confident that they are taking part in a properly regulated scheme that will provide them with real benefits.

Green Deal Conduit

The current working name for a new organisation that will build a large network of small and medium-sized organisations involved in the assessment and refurbishment of buildings across the UK. Backing this initiative is a wide range of professional institutions and trade associations including Federation of Master Builders, National Federation of Builders, Royal Institute of British Architects and Royal Institute of Chartered Surveyors.

Green Deal Finance Company

A not-for-profit company set up to investigate how to provide the lowest cost finance to the Green Deal, to enable a competitive market and maximise the Green Deal measures that can be implemented across the United Kingdom. Members include British Gas, Carillion, E.ON, EDF Energy, Insta Group, Kingfisher, Mark Group, nPower and SSE.

Green Deal Installer

Only a certificated Green Deal Installer can install energy efficiency measures under the Green Deal finance mechanism and use the Green Deal Mark. For more information on how to become a Green Deal Installer visit the Green Deal Oversight and Registration Body website set-up DECC.

Green Deal Oversight Body and Registration Body

An independent body to manage the day-to-day activities of the Green Deal on behalf of DECC. It will manage the approval process for installers, assessors and products. This independent body has been confirmed as Gemserv.

Green Deal Plan

This is the contract between the Green Deal Provider, the installer and the bill payer (if different at the property). It sets out the financial terms of the agreement (e.g. amount and duration of installments).

Green Deal Provider

A Green Deal Provider produces a Green Deal Plan and determines if the plan meets the 'Golden Rule'. They also arrange the finance and appoint an authorised Green Deal installer to undertake the installation of the improvement measures.

Occupancy Assessment

The second part of the Green Deal assessment. The occupancy assessment considers the energy use of the household and the impact this is likely to have on the standard energy savings predicted by the EPC. It also contains a Green Deal Advice Report.

MCS Installer

An installer certified under the Microgeneration Certification Scheme by an accredited certification body.


The production of heat and/or electricity on a small-scale from a low carbon source. Micro-renewables is the all encompassing phrase for renewable and energy efficient technology including ground and air source heat pumps, solar thermal, solar PV (photovoltaic), biomass and combined heat and power (Micro-CHP) A subset of SAP (Standard Assessment Procedure) created specifically for existing buildings and assesses a reduced amount of building elements. It is designed to comply with Building Regulation PartL1B.

Property Assessment

An assessment of the property to determine the correct measures that can be installed to improve the energy and thermal performance of the building and ensure eligibility for Green Deal finance. An assessment must be carried out by a certificated Green Deal Assessor.

SAP (Standard Assessment Procedure)

The Government's nationwide approved method for calculating energy efficiency and carbon emissions from homes to demonstrate compliance with Building Regulations

Smart Meters

Smart meters are high-tech electricity and gas meters that will replace existing meters under an £11 billion Government plan. The official smart meter roll-out is happening between 2014 and 2019. Smart meters will measure a property's exact gas and electricity use and send all the information back to the energy supplier either directly, or via a data-processing centre – without the need for someone to come and take meter readings