10 ways to make construction projects greener
Around 10% of the UK’s carbon dioxide emissions are directly associated with construction. Daniel Brooks-Dowsett explains how project managers can make their work more sustainable.
The construction, operation and maintenance of the built environment accounts for 45% of total UK carbon emissions, with 10% down to the build, according to the UK Green Building Council.
In addition, 32% of landfill waste comes from the construction and demolition of buildings and 13% of products delivered to construction sites are sent directly to landfill without having even being used.
So how can those working in the industry identify construction methods with reduce the environmental impact?
- Energy. Preserving energy is an important consideration during construction. Insulating the external envelope of a building as soon as the shell is complete and avoiding draughts and heat leakages can help to reduce energy use. 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.
- Water. After such a long, hot summer, we should be 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 can 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.
- Equipment. Use of high quality fuel sources (particularly renewables), and ensuring correct equipment lubrication, benefit the sustainable management of equipment. Doing a few calculations and selecting an appropriately sized generator can significantly reduce both energy usage and cost.
- Materials. The astute construction manager will have knowledge of the respective benefits and dangers of construction components. Lime mortars are 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 required setting times. CO2 can be reduced by substituting cement with Pulverised Fuel Ash (PFA) or Ground Granulated Blast Furnace Slag (GGBS). Use materials with high recycled content and use local suppliers.
- Manage pollutants. Be aware of the potential effects of harmful materials and 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. Methods for preventing or reducing pollution include the use of pre-cut building materials and silica-free abrasives (which reduce risk when blasting).
- Waste management. There is a 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 in 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.
- Invest in digital. BIM can make design and construction more efficient, reducing the unnecessary cutting of components on site and optimising the programme.
- Offsite construction. This can have the benefit of reducing on-site waste, disruption to local residents, air or light or sound pollution and lorry journeys. By cutting wood or metal products in a factory, waste is more likely to be recycled or disposed of appropriately.
- Supply chain. Encourage suppliers to sourcing sustainable materials and where possible use local labour and products.
- Site management. 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 using EPC criteria in relation to the site office to ensure that it is operating efficiently.
Daniel Brooks-Dowsett is a director Trident Building Consultancy.