Wednesday, 21 February 2007

Greenhouse emissions could be reduced through planning and urban design

Given recent attention on emissions, I was wondering how often we think, as planners, of how planning and urban design could reduce emissions.

In fact, have you ever though about how greenhouse emissions could be reduced through planning and urban design? Here’s a few things planning authorities could do.

Three types of changes to traditional urban form could reduce greenhouse gas emissions: increasing densities on the fringe, general urban consolidation within existing urban areas, and more intensive mixed use local activity centres close to public transport nodes. Studies indicate the potential for reductions in greenhouse emissions with higher densities, more mixed use and energy efficient dwelling design. There are many opportunities for reducing greenhouse emissions in the urban planning stage, through considering:

• integration with transport modes and systems
• location
• infrastructure
• site design
• building design
• choice of appliances and fittings

These can be targeted via:

• identifying sites suitable for higher density development (greenfields or urban consolidation) with particular attention to access to public transport;
• developing codes, guidelines and performance standards to improve the treatment of energy and transport issues, including explicit reference to the greenhouse-efficiency of urban form, building design and building operation;
• including greenhouse issues when negotiating site and building requirements.

Note: Urban consolidation is policy in Ireland now, and much medium density development is taking place close to public transport.

Other actions to reduce greenhouse emissions related to urban form and development.

Planning authorities can take a range of other actions to reduce greenhouse emissions related to urban form and development. For example, they can:

• support more mixed-use energy-efficient public transport-oriented development around nodes within established cities and in new development areas;
• use infill development on sites close to public transport;
• limit car parking allocations for medium density development;
• be more proactive in regulatory and educational measures; and
• develop new mixed-use higher-density zones and apply mandatory density and energy efficiency criteria.

There are many opportunities for local councils to use the planning process to reduce greenhouse gas emissions. This is important as few councils have included specific reference to energy efficiency or greenhouse considerations in their policies and planning schemes for development in their areas. Irish designs and building practices have so far achieved only poor energy efficiency.

A major reason has been that planning permission for land development is reactive: designs are routinely drawn up by the development company, and then councils formally ratify these, having exerted little influence on their form.

Councils will need to be much more proactive and seek to set agendas rather than just provide an approvals mechanism for decisions essentially made before the process begins.

Planning authorities have enough power under planning and building legislation to develop design parameters which could be marketed strongly and used as the basis for voluntary agreements with developers or included in various ways in statutory approvals processes. This is a particularly powerful tool at the rezoning stage, but could also be used with effect in the planning permission-issuing process.

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