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The Merton Rule was a ground breaking planning policy, developed by Merton Council, which required new developments to generate at least 10% of their energy needs from on-site renewable energy equipment, in order to help reduce annual carbon dioxide (CO2) emissions in the built environment. The rule applied to all types of buildings, not just homes.
Merton Council developed the rule and adopted it in 2003. Since then the Mayor of London and many councils implemented it, and it became part of national planning guidance.
Our planning policies have since changed, and the Merton Rule has been superseded by new energy requirements in building regulations.
"The council will encourage the energy efficient design of buildings
and their layout and orientation on site. All new non residential developments above a
threshold of 1,000sqm will be expected to incorporate renewable energy production equipment to provide
at least 10% of predicted energy requirements.
"The use of sustainable building materials and the re-use of
materials will also be encouraged, as will the use of recycled aggregates in the construction of buildings.
This will be subject to the impact on the amenity of the local environment, taking into account the
existing character of the area."
The justification sets out that where the incorporation of renewable energy equipment would make the development unviable it will not be expected. So for example for technical reasons it may not be possible to mount solar or wind methods on a roof.
The justification also sets out the means of generating renewable energy to be photovoltaic energy, solar-powered and geo-thermal water heating, energy crops and biomass, but not energy from domestic or industrial waste.
Merton Council worked with other authorities, professions and industry to embed the Merton Rule into the mainstream, and was instrumental in persuading the UK Government to include an addition in its national planning policy guidance (PPS22), confirming the legality of such policies. With the policy nationally accepted, Merton officers have been working with others to spread good practice and knowledge.
The Merton Rule has led to manufactures of energy related construction products changing product lines. For example, after hosting a series of seminars, addressed by Merton officers, Mitsubishi Electrical developed a new range of heating and ventilation equipment that would meet the Merton Rule requirements. The Merton Rule is proving to be a boost to industry in the sector.
We have estimated that if applied nationally the application of the Merton Rule equates to an annual total renewable energy infrastructure industry of £1,125,000,000 - delivering a CO2 reduction of 160,000 tonnes.
Furthermore, if the Merton Rule policy is adopted for new housing by every council, it will trigger sufficient growth in the industry to create economies of scale that will reduce equipment costs to the point where they will become affordable to homeowners who want to 'retrofit' their homes.
Below is an outline of how the Merton Rule policy was applied:
Merton Council hosted a conference about the Merton Rule in 2008. The speakers' presentations are available below.
The inclusion of energy requirements in building regulations has superseded the need for a prescriptive renewable energy targets for new development for an outer urban borough like Merton. We have adopted a new approach; as set out in Core Planning Strategy policy CS15 of the Local Development Framework, using nationally recognised sustainable design and construction standards. However, our new approach does not exclude the effectiveness of implementing ‘Merton Rule’ style renewable energy policies in other areas where there is greater scope for, and likely more effectiveness, from renewable energy installations.
Strategic Policy and Research
London Borough of Merton
12th Floor Merton Civic Centre
Telephone: 020 8545 3837
Fax: 020 8545 4160
This page was last updated on Monday 10 October 2016