This brief guidance mainly focusses on the UK, drawing on other countries as pertinent.
The main government policies that impact on sustainability in structural engineering are:
- Landfill tax
- Aggregates levy
- Circular economy
- Zero carbon buildings
Landfill tax
The UK Landfill Tax was introduced in 1996, driven in part by the EU Landfill Directive. Its aim was to make advanced waste treatment technologies more financially attractive by increasing landfill fees.
The amount of tax levied is calculated according to the weight of the material disposed of and whether it is ‘standard’ or ‘lower rate’ waste. The landfill site operator is responsible for paying landfill tax, however they pass the cost on to users.
- ‘Lower rate’ waste is defined as non-hazardous with low potential for greenhouse gas emission or environmental pollution1. The definition covers most materials used in a building's fabric. It also covers earth excavated for foundations, most forms of concrete, brick, glass, soil, clay and gravel
- ‘Standard’ waste covers all other forms of waste such as wood, ductwork, piping and plastics2
As at 2020, landfill rates are £3.00 / tonne (lower rate for inactive waste) and £94.15/ tonne (standard rate for active waste)3. These rates are likely to rise with inflation (Retail Prices Index). The policy has been successful in reducing the amount of waste sent to landfill by 70% from 2000 levels4.
Aggregates levy
The Aggregates Levy was introduced in 2002. It is a tax on sand, gravel and rock that has either been dug from the ground, dredged from the sea in UK waters or imported5. The rate has risen since inception but has been at £2/tonne since 20096; it is factored into the cost of concrete by the supply chain. There are specific circumstances where the levy does not apply to a project. For example, if no structure is being improved or if gravel is sourced on-site but only used for pathways6 – seek specialist advice if your project could qualify.
Circular economy
The ‘Circular Economy’ concept is to reduce waste and resource inputs into the economy by reusing, recycling and otherwise slowing/closing material and energy loops7. It is not mandated by government anywhere, though it is actively promoted by the Ellen MacArthur Foundation and has been consulted on by the EU8. Structural engineers could implement a circular economy strategy by designing with reused elements (eg with beams identified from a structure being taken down), by designing for deconstruction (eg using reversible connections and including a deconstruction plan in client documents), and by using materials with low embodied energy very efficiently9.
Zero carbon buildings
Zero Carbon Buildings are defined as having a yearly net carbon footprint of zero. Such buildings are highly energy efficient by being well-insulated and airtight. This can result in more embodied carbon in the fabric and facade. The energy for use is generated renewably on-/near-/off-site. Excess energy from these sources is then sold to the grid too ‘offset’ the construction and any other impacts to give a net zero (or even negative) carbon building10.
Although many governments provide support for low carbon buildings, none mandates them yet. However, building regulations in Germany and Sweden require levels of energy efficiency that are compatible with zero carbon homes11.
The Code for Sustainable Homes was introduced in 2006 as a voluntary standard. It was an environmental assessment method for rating and certifying the performance of new homes in United Kingdom12. It set criteria for the sustainable design and construction of new homes at different levels. It aimed to reduce carbon emissions and promote higher standards of sustainable design. Although the stated aspiration was that all new homes would have to be net zero carbon by 2016 (defined as Code level 3), in 2015 the Government withdrew the Code, consolidating some provisions into Building Regulations13.
The UN Paris Agreement on Climate Change aims to limit the rise in global temperatures to “well below” 2°C above pre-industrial levels. Each country’s ‘nationally defined contributions’ to this aim are evaluated and reviewed every five years14. Achieving this aim will require all countries to construct much more low- and zero-carbon buildings15.
References:
[1] Excise Notice LFT1: a general guide to Landfill Tax
[2] Landfill tax
[3] Landfill tax rates
[4] Landfill tax increase in rates
[5] Aggregates levy
[6] Excise Notice AGL1: Aggregates Levy
[7] What is a circular economy? A framework for an economy that is restorative and regenerative by design
[8] Circular economy and waste markets: UK government response to European Commission consultations
[9] Practical how-to guide: Build Circular Economy Thinking Into Your Projects
[10] Zero carbon housing
[11] Zero Carbon Compendium; Who's Doing What in Housing Worldwide
[12] Code for Sustainable Homes
[13] Building Regulations - Conservation of fuel and power: Approved document l
[14] Paris Agreement
[15] Building the path to 1.5°C: What the Paris Agreement Means for Buildings & Construction