Identifying, assessing and minimising the risks

As construction has the potential to contribute a significant portion of the emissions during a development’s life cycle, it is important to consider mitigation measures for the construction stage. This is done to reduce the emissions associated with construction methods and embodied emissions in construction materials.

Developers should aim to reduce the embodied carbon content by ensuring the materials specification and products considered have the following characteristics:

• low embodied energy, e.g. by using the Green guide to specification, or increasing the efficiency of the design and reducing the amount of materials required;
• high recycled content, replacing virgin materials, e.g. cement replacement in concrete or recycled steel/aluminium;
• locally extracted and manufactured materials; and
• construction techniques that minimise energy use.

(See also the 2012 RICS guidance note Methodology to calculate embodied carbon, 1st edition.)

Operational stage – reducing emissions

Designing for the reduction of operational emissions caused by a project is intrinsically linked to the mitigation of climate change. All developments must consider the reduction of carbon emissions through building regulations (Part L compliance) or stricter local planning requirements. Greater detail on energy efficiency can be found in the ‘putting it into practice’ sub-section of isurv’s Key concepts in sustainability. Using the example of the London scheme, the development needed to be designed to deliver a 35% reduction from Building Regulations Part L 2013 after following the energy hierarchy of ‘lean, clean and green’.

Energy efficiency must first be maximised, adopting passive measures such as orientation, shading and thermal mass, to ensure that overall energy demand is minimised. Any energy-consuming plant and equipment in the development needs to be as efficient as possible, further reducing the overall demand. For example, the use of combined cooling, heat and power (CCHP) engine(s) with highly efficient boilers and use of heat exchanging technologies are significantly more efficient and less carbon intensive than traditional boilers, chillers and purchased grid electricity. Remaining energy demand should then be met, where possible, through the use of low and zero carbon technologies such as photovoltaic panels.

Water use

In terms of providing mitigation for climate change impacts on water shortages, developments can adopt principles to reduce the use of potable (drinking) water. This may include the use of a rainwater harvesting or a grey water recycling system to provide water for use in landscape irrigation or toilet flushing. It is widely accepted that a water consumption target of 105 litres per person per day for residential dwellings can be achieved, as well as the use of specified low flow rate fittings and equipment for non-domestic buildings.