Improving building environmental performance during construction

[edit] Introduction

The construction industry is responsible for 45% of total UK carbon emissions and 32% of the waste sent to landfill in the UK. Consequently, many of those working in the industry are opting for construction methods with the least environmental impact. Below are ten ways to help tackle the issue.

[edit] Energy

Preserving energy is an important consideration during construction. Insulating the external envelope of a building once the shell is complete and avoiding draughts and heat leakage can help to reduce fossil fuel consumptio. It is also good practice to use natural daylight in place of electric lighting, and solar lighting when working at night or during the winter.

[edit] Water

In recent years we have experienced some unusually long, hot summers, so we are more aware than ever of the finite quantity of available water and the energy required to make it suitable for human consumption (approximately 1.2 kWh for every cubic metre of water cleaned to potable levels). Construction managers have the opportunity to address this by implementing systems that limit water usage, maximising the use of run-off and rain water – but must also be aware of the dangers of chemical treatments used in greywater recycling systems.

[edit] Equipment

Using high-quality fuels (in particular renewables) and ensuring correct equipment lubrication benefits the sustainable management of equipment. Doing a few calculations and selecting an appropriately sized generator can significantly reduce both energy usage and cost.

[edit] Materials

The astute construction manager will have knowledge of the respective benefits and dangers of construction components. For example, lime mortars can be preferable to Portland cement mortars because bricks bonded with lime mortar can be reused in the future. Ash or brick dust can be added to lime mortar to enhance durability and shorten setting times. Similarly, carbon emissions can be reduced by substituting cement with Pulverised Fuel Ash (PFA) or Ground Granulated Blast Furnace Slag (GGBS).

It is also worth considering the increasing range of recycled materials readily available – from aggregate to metals.

All too often, construction requires a small amount of a material which is only available in large quantities. In this case it is often possible to use a materials exchange scheme, or to plan to use the material for future jobs. When specifying materials, opt for those that have a good recyclate content, aim to use local suppliers, reclaimed and recycled building products and those which have an environmental kite mark.

[edit] Managing pollutants

It important to be aware of the potential effects of harmful materials and to understand how best to handle and dispose of toxic materials such as asbestos and cement dust. Pollutants also include the inevitable by-products of construction: smoke, fumes, gases, dust, steam, odour, noise and light. The construction manager must ensure that all those working on site, and as appropriate, the local community, are adequately protected.

Methods for preventing or reducing pollution include the use of pre-cut building materials and silica-free abrasives (which reduce risk when blasting) and adopting the least polluting construction methods – for example reducing the unnecessarily use of powerful tools.

[edit] Waste management

There is a fine balance to be struck between disposing of materials on a frequent basis because of the immediate environmental impact and reducing lorry journeys. Standards and methodologies such as those developed by the BRE can assist in determining the best course of action.

Design the use of on-site waste management systems from the start. Significant savings can be made by pre-sorting site waste and using management systems such as SMARTwaste or WasteCostLite.

To prevent waste, material quantities should be considered carefully in advance but taking into account time constraints – for example, the short shelf-life of ready-mixed mortar. It is also worth considering the services of waste management companies who can advise on practical recycling schemes, provide segregated waste containers, waste collection and recycling services, and disposal of waste at recycling centres.

[edit] Investing in efficiencies

Technology such as Building Information Management (BIM) can be used to inform the cutting of items such as sheet metal efficiently. Furthermore, doing so in a controlled environment can avoid the shape-changing problems caused by cold or hot weather.

[edit] Offsite construction

Offsite construction can have the benefit of reducing on-site waste, disruption to local residents, air / light / sound pollution and lorry journeys. This can range from selecting individual prefabricated materials to constructing large parts of a building’s structure in more appropriate surroundings.

Frequently this results in greater efficiencies. For example, in cutting wood or metal products offsite where specialist technology reduces waste, and any off-cuts are more likely to be recycled or disposed of appropriately.

[edit] Supply chain

The prospect of assessing an entire supply chain can seem a mammoth task but at its most basic it simply refers to specifying and sourcing sustainable materials, and where possible selecting local labour and products.

[edit] Site management

Sustainable site management goes beyond simple procedures such as wheel washing and general maintenance.

Energy performance certificates (EPCs) are not only for the completed building itself but can also be applied to site offices. Whether or not you are required to have an EPC assessment, it is worth assessing EPC criteria in relation to the site office to ensure that it is operating efficiently.

Essentially, a construction manager’s approach to sustainability comes down to planning a ‘lean’ approach: on a basic level, identifying wasteful activities and eliminating them; and on a more advanced level, investing in methodologies and technologies to manage-in efficiencies.

The challenge for construction managers today is to balance the requirements of the job with energy and resource efficiency, and in doing so, keeping abreast of an increasing array of technology and maintenance practices. The methods currently available have begun to fundamentally transform construction and it is within the scope of each construction manager to advance the industry’s take-up of beneficial practices.