Construction and use
Land Design Planning Contracting Refurb End of life
The construction and use stage entails the following elements.
- Physical construction works
- Waste management
- Project handover
- Operational performance
This is a resource-intensive stage which will set up the delivery of sustainability for the asset’s life. Moreover, there are significant costs incurred at this stage, providing a strong business case to be made for embedding sustainability into construction and operational performance.
What opportunities are there to make construction more sustainable?
Traditional construction costs represent 10-20% of a building’s total life costs, of which waste costs account for up to 5% of construction project value. In fact, nearly 20% of all construction wastes in UK are materials that are never used.
However, sustainability construction processes can provide cost-savings through improved waste minimisation and waste management. WRAP specifically provides support for efficiently dealing with waste. It provides advice to help achieve materials efficiency and reduce wastes, including publications on construction logistics. The Construction Resources & Waste Platform (CRWP) provides a useful ‘one-stop shop’ web-based resource for benefits of sustainability and construction waste.
Building operating costs stem from the costs of using the building throughout any period where the building is occupied. Operating a building gives rise to the use of natural resources and the production of waste products and emissions. The highest operational costs tend to stem from energy use, as compared to, for example, ground maintenance costs.
A breakdown of building energy costs is provided from a Royal Institute of Chartered Surveyors (RICS) presentation to Green Build (2005), developed in partnership with CBRE. This presentation estimates energy costs 30% of total operating costs, representing the largest percentage of operating costs.
Buildings rarely function initially as they were originally designed but require adjustment following a period of being in use. In addition, building controls may be adjusted throughout building use so that the building reacts to the external environmental conditions in the optimum way and not as originally commissioned.
This cycle may take a number of years to perfect but will ensure that the energy use of the building in service is minimised and that the landlord and tenant are getting the best out of the building they own and occupy respectively.
A California Energy Commission case study demonstrates the success of a building energy controls system installation in a multi-tenanted, major office building. This building energy control system, ‘enhanced automation’, allowed owners Macanan Investments to track energy use and demand for each tenant through alterations made to the building’s lighting controls and energy information system. The result was reduced energy use by an average of 34% during the 2001 peak demand period compared to the previous year, while maintaining tenant comfort.
Sustainable construction can also provide benefits of minimising requirements for repairs and maintenance, redevelopment (in a worst case scenario), and thereby minimising impact on an organisation of having to deal with these issues. For more information see the Managing land & buildings module of this website.
In addition, the World Business Council for Sustainable Development (WBCSD) report, "Energy Efficiency in Buildings: Business realities and opportunities" highlights barriers to energy efficiency in operational buildings. One of the challenges to overcome is that building professionals may tend to underestimate the contribution of buildings’ energy to climate change and to overestimate the cost of saving energy.
Key considerations
- How can sustainability be taken into account at this stage?
- What actions taken during the physical construction works stage can provide sustainable benefits?
- How can sustainability be taken into account during transfer from construction to operation?
- How can I reduce waste costs?
- What opportunities exist at Project Handover and Post-occupancy Assessments?
1. How can sustainability be taken into account at this stage?
Prior to commencing construction works, it is beneficial to check to ensure the project brief reflects requirements established in the former design and planning stages. This will minimise costly changes/abortive work, that increase materials, waste and energy costs of construction.
During the contracting stage, the winning bidder should prepare sustainable construction and site waste management plans that include the following.
- Identify roles and clearly issue responsibilities for materials and waste handling
- Establish and clarify targets for efficiency
- Provide clear guidance on what the plans entails
- Have buy-in from both client and sub-contractors
- Are accompanied by training of management and training of site workers on the relevant site management techniques and sustainable practices operating on site
Strong programme and project management should be in place to embed the principles of the plans in design and construction practice.
The Crest Nicholson case study, ‘Construction Waste Management Plans’ illustrates the company’s re-assessment of its contractor selection procedures, supplementing economic, technical and quality criteria with an environmental assessment form for contractors which included aspects of waste management and material / product selection.
2. What actions taken during the physical construction works stage can provide sustainable benefits?
CIRIA and the Building Research Establishment Environmental Assessment Method (BREEAM) provide useful guidance on savings possible through sustainable construction:
- Use of material recovered from the site and non-primary materials should be encouraged at every opportunity;
- A cost comparison between dealing with waste and recycling will lead to a greater understanding of the advantages of recycling and waste minimisation;
- Disposal costs due to Landfill Tax can be minimised by segregation of wastes; and
- Key Performance Indicators (KPIs) should include waste and recycling (of aggregates and waste materials) costs and be monitored throughout the construction process.
The Considerate Construction Scheme (CCS) is a national initiative concerned with any construction activity. Sites registered with the CCS undergo a performance assessment against the eight point Code of Considerate Practice which includes the categories Considerate, Environment, Cleanliness, Good Neighbour, Respectful, Safe, Responsible and Accountable.
The Gazeley case study page, ‘Eco-template and lifecycle analysis’ describes the environmental costs and the environmental initiatives that the company delivers for its customers at every step of the development process from land design, project assembly, procurement and delivery through to the in use and end of life phases of a project.
3. How can sustainability be taken into account during transfer from construction to operation?
Prior to handover, assessors such as Building Research Establishment Environmental Assessment Method (BREEAM) qualified professionals should assess whether the development’s sustainability requirements (for example, the Key Performance indicators and sustainability specification) have been met. If not, remedial action should be sought.
Handover procedures should include checklists for the following items.
- Natural environment
- Water
- Waste
- Energy
These checklists should address issues such as completion and operational functionality of Building Energy Management System (BEMS) connections, and against which performance should be re-assessed twelve months later. This is the time when building occupants settle into the facility, becoming familiar with its use. A more detailed explanation of post-occupancy assessments is provided in point 5 below.
The Sustainability Assessment Model case study demonstrates how this model can be used to assess project performance through monetising project impacts so that they can be compared on a like-for-like basis. This also allows the impacts to be combined into a single measure which reflects the overall sustainable development performance of a project.
The Arup case study on Kingspan Insulation, ‘Improving Company Performance through SPeAR’ illustrates a tool that compares the strengths and weaknesses of a project and helps to lead the decisions for making improvements.
4. How can I reduce waste costs?
There is a strong business case to be made for a sustainable approach to building construction activities, whether for new build or refurbishment works. Waste minimisation and waste management provide opportunities to achieve savings. Consider the costs associated with waste and how embedding principles to minimise these costs could reduce these costs for specific construction projects.
Waste materials require disposal, which entails transport (and thereby, carbon emissions) to disposal sites, most often incineration plants, landfills (with landfill taxes increasing landfill taxes) and recycling depots.
Waste Aware Construction estimates construction activity wastes are comprised predominantly of the following materials.
- Wood
- Plasterboard
- Cardboard packaging
- Metals
When taken together, the first three on average amount to 80% of construction waste (in terms of weight per meter square of the build).
Waste costs also include the following elements.
- Lost value of raw materials unnecessarily disposed of in skip
- Costs of labour
- Energy costs (e.g. fuel for transport)
Envirowise has produced case studies illustrating a variety of resource efficiency, cost reductions and savings, and waste minimisation topics.
5. What opportunities exist at Project Handover and Post-occupancy Assessments?
Project handover is an opportunity to catch the sustainability snags and ensure that the completed construction activity is on par with the sustainability specification.
Project handover should include detailed assessments of the completed construction project, including evaluation of the following aspects.
- Construction waste management requirements
- Energy management system functionality
- Water supplies and drainage (increasingly important in consideration of climate change adaptation)
- Achievement of Key Performance Indicators (KPIs)
Post-occupancy evaluations take place one year after sign-off of project handover. This is an opportunity to:
- redress any development project issues;
- feedback on sustainable procurement processes undertaken for the construction activities; and
- document any lessons learned.
Both objective and subjective techniques are used to make these assessments, for example, personal responses to questions, observations, documentation and technical audits.
The Sustainable Procurement Task Force provides case studies of the benefits of undertaking these assessments.
General post-occupancy evaluation advice can be found on the Re-Thinking website, a private service provider that aims to support embedding sustainability into project delivery processes, including guidance on post-occupancy evaluations.
Are there key considerations we haven’t included? If so, please let us know.
The following are a set of questions you should be asking yourself at this stage of the construction process.
- How can sustainability be maximised during the physical construction works/building process itself?
How can noise and disruption to the local community be minimised during physical construction activities?
How can transport of vehicles to and from site be minimised during physical construction activities?
How can waste from the construction process be minimised during physical construction activities?
Should accepted standards, e.g. the considerate constructors scheme, be followed? - What impact does sustainability have on building operations throughout building use?
How can users influence the design process to ensure it is appropriate to user needs?
Are users/operators involved early enough in the design process?
How can users achieve operational cost savings through more sustainable use of the building?
How do users understand how the building should be operated? Is there training or guidance provided to facilities managers and/or occupiers?
If the Facilities Manager leaves, will the replacement understand how to operate a sustainable building?
Should post-occupancy performance of the building be monitored and evaluated, and with whom should this information be shared?
Are there operational benchmarks to compare new operations against?