Yorkon News Archives

23/01/2007 – How Off-site Construction is Meeting the Sustainability Challenge for New Buildings

David Johnson, Director and General Manager of award-winning off-site specialists, Yorkon, looks at how modular construction is meeting the sustainability challenge and helping to deliver new buildings that minimise impact on the environment.

Module manufacture The issue of sustainability is growing ever more important in the world we live in and construction has perhaps the greatest impact than any other sector or activity. New legislation is forcing construction clients, designers and contractors to adopt a more sustainable approach, and interest from the wider public and pressure groups will add to the pressure for change.

The reasons for this change have been widely publicised – the world’s diminishing natural resources, the acceleration and effect of global warming, and the need to develop sustainable communities where people can live, work and contribute to their built environments.

When designing for sustainability, the most easily understood objective is to reduce and conserve the energy consumed in a building, which has a direct technological response. However, what constitutes sustainable development should also include the quality of the place, the internal environment, the mix of social and economic factors, and the construction site as a consumer of resources.

The challenge for construction clients, architects and contractors lies in how buildings can be designed in the environment we have inherited. The space available for new buildings and their interfaces with existing facilities often requires ingenuity to create attractive, stimulating architecture that meets occupiers’ practical requirements. Consideration has to be given to orientation, material selection, recognition of the actual building process as a consumer of resources, and the inclusion of a long-term strategy for energy consumption.

The fact that off-site construction can reduce programme times for new buildings by up to 50 per cent has been well documented. The sustainability advantages of modular buildings, however, have been less well publicised, and until now, there has been little evidence to prove the case that off-site construction is a more sustainable method of delivering high quality accommodation solutions.

How Off-site Construction can Reduce Carbon Emissions

The Government has committed to making all its estate carbon neutral by 2012. Inefficient buildings are responsible for half of the UK’s carbon emissions, which the Government has pledged to reduce by 20 per cent by 2010 and 60 per cent by 2050.

Air leaking in and out of any building, greatly inhibits the energy efficiency of its structure and easily undermines the best thermal insulation. By minimising air leaking in a building, a warm, draught-free internal environment is delivered, with lower running costs, reduced capital equipment costs and the corresponding reductions in carbon dioxide emissions.

Full scale tests for air permeability carried out by Yorkon have shown that its modular buildings consistently perform up to 70 per cent better than traditional site-based construction. The air pressure tests were carried out on a wide range of completed Yorkon buildings in accordance with Building Regulations Part L and demonstrate how its steel-framed modular technology can achieve a higher degree of precision, leading to improved thermal efficiency, lower running costs and reduced carbon emissions.

Modular buildings are factory-built off site to quality-controlled standards, using highly trained operatives and a high degree of repeatability. There are no wet trades so shrinkage and structural movement after the building has been sited are also highly unlikely. These factors mean that modular buildings can perform well in excess of the minimum standards set out in the Building Regulations – a significant environmental benefit.

The Yorkon modular system uses a steel-framed design, which minimises thermal bridges and makes the buildings easier to heat. A composite panel construction also ensures continuity of insulation across the building envelope, ensuring there are none of the cavities associated with loose-fill insulation. This design feature reduces the risk of condensation, which can reduce the thermal effectiveness of a building and is unique to Yorkon in the modular industry.

A More Environmentally Efficient Building Process

Pressure is increasing on the construction industry to halve the amount of material waste going to landfill sites in the next six years. The Waste and Resources Action Programme (WRAP) states that UK construction consumes more than 400m tonnes of materials each year, generating 100m tonnes of waste.

The use of off-site construction can significantly reduce waste of materials compared to site-based building methods because much of the work takes place in a controlled factory environment. This makes waste segregation and recycling much easier. As a subsidiary of Portakabin, Yorkon has achieved a 50 per cent reduction in waste sent to landfill over the last three years and 65 per cent of waste is recycled. The company also has in place an Employee Awareness Scheme to further reduce waste and energy consumption, and encourage recycling through the segregation of plastic, cardboard, polythene, timber and paper.

Other initiatives include the recycling of all window and door cut-outs, and work with the Carbon Trust to reduce the amount of compressed air and energy used in the manufacturing process.

It has also been claimed that up to 67 per cent less energy is required to produce a modular building compared to an equivalent traditionally built project (source: Arup Research and Development). And off-site construction can generate up to 90 per cent fewer vehicle movements to site (source: Mtech), which offers clear environmental benefits, as well as reducing disruption to existing operations during construction.

Developing a Sustainability Strategy for the Design of New Buildings

Whole life costing is now a requirement for all public sector building contracts, and PFI and PPP schemes. It is also central to sustainable development.

The use of advanced building simulation software, such as the system recently introduced by Yorkon, will allow a detailed environmental analysis to be carried out for every project at the earliest design stage. This powerful tool will assess the impact of specification decisions on capital cost, energy consumption, carbon emissions and running costs over the life cycle of a building to produce the most sustainable design solution for each modular building project.

The system enables the design to be value engineered around functionality and environmental performance, improving energy efficiency and ensuring a cost-effective sustainability strategy for the life of the building. The software will prevent over-specification of M&E plant and facilitates compliance with the revised Building Regulations. It will also generate invaluable data on annual carbon emissions, heating and cooling costs per square metre, whole life costing, energy audits and air quality by individual room, ensuring a pleasant internal environment.

How to Assess the Environment Performance of a Modular Manufacturer

The demand for off-site construction continues to increase in every sector, and consequently, there are a greater number of specialist contractors than ever before. It is therefore critical in the selection of a modular partner, that construction clients compare manufacturers and systems that are like for like.

As well as considering factors such as track record, statistics for repeat business and the number of projects delivered on time and on budget, developers should now be looking closely at contractors’ policies on sustainability. Some of the areas to consider, which also apply to traditional site-based building contractors, include:

Does the modular specialist have an ongoing commitment and policy on sustainability?

Are they working in line with the Sustainability Charter issued by the Major Contractors Group?

Can the manufacturer or contractor demonstrate ongoing reductions in waste and carbon emissions generated in the production process?
What energy saving targets are in place?
What is the manufacturer’s approach to the design of sustainable buildings?
What inhouse capability do they have to value engineer the building design for maximum energy efficiency?
How does the building system perform in areas such as air permeability and ventilation to meet Building Regulations Part L and Part F? Look closely at the test results achieved for completed buildings.
Is the modular specialist actively looking at low or zero carbon technology to further enhance the environmental performance of its buildings?

Adopting a more sustainable approach to construction does not have to increase costs but it can add considerable value to a building project. And the use of modern methods of construction, such as modular building systems, can help clients, contractors and architects achieve their sustainability objectives with all the other speed, quality and efficiency benefits associated with off-site construction.