A new era in concrete construction

UK Insulating Concrete Formwork Association: A new era in concrete construction

Guo-Heritage, Pauline

Insulating Concrete Formwork (ICF) is an innovative building system whereby expanded polystyrene (EPS) is used as formwork for in-situ concrete structures’1′. The formwork is then left permanently in position to provide thermal insulation. Figures 1-4 show ICF house construction in progress.

ICF was first used in the US more than 50 years ago. The systems have been further developed, receiving widespread use across the US and mainland Europe, particularly during the last 30 years. The system combines the thermal mass properties of concrete and excellent insulation. ICF is an energy-efficient building system which has been widely used in zero, ultra-low and low-energy buildings.

Low carbon emission technology

However, few are aware of the extent to which ICF systems may reduce energy use and CO2 emissions. A simple estimate was undertaken and it is apparent that, by saving spaceheating energy, ICF could reduce 45,000 tonnes of CO2 emissions over a five-year period in the UK. This calculation is based on the number of new dwellings to be built (UK government projection of households) and assumes that ICF housing market share increases at 1% per annum. This estimate is very conservative, taking into account that ICF saves 20% of space-heating energy. Recent research shows that 35-50% saving can be expected(2-4).

This estimate focuses on the operational energy saving (space-heating energy saving) of an ICF system. The embodied energy of different systems is insignificant when compared with the energy used for heating during the house lifespan of 60 years. The figure may seem insignificant as it is only based upon a small number of ICF houses built and used over a five-year period. In reality, ICF houses reduce space-heating energy over their lifespan and can therefore directly lead to long-term reductions in CO2 emissions. This projection does not include the carbon emission savings of ICF used in existing houses (renovations/retrofit), or buildings other than domestic houses.

Other benefits

ICF has many other environmental, social and economic benefits. It can be used to create high-quality, affordable homes within a tight timeframe. The system permits a considerable degree of architectural flexibility and ICF houses can look completely traditional or totally modern (see Figures 4-6). ICF is also an excellent system for basement construction(5).

Basements in housing can save a further 10% energy and, by increasing usable floor area, support government policy for increased housing density. ICF has lower labour and equipment requirements and its use serves to improve site health and safety, reducing wastage. It is a recyclable material with lower embodied transportation energy as ready-mixed concrete is a locally sourced material. Figure 7 is a non-comprehensive flowchart covering ICF lifecycle and associated benefits.

Increased use

It is not surprising that this sustainable system is achieving greater use. In the US, ICF dwellings accounted for a 3.8% share of the residential market in 2002, representing a 40% increase over 2001. There were 1920ICF dwellings built in Canada during 2002. In the UK, ICF dwellings are mainly used in energy-efficient demonstration projects with a small share of the self-build market. Use of the system has not yet entered mainstream residential construction. In the UK, 175,000 new houses were built in 2002, of which approximately 300 used ICF. The technique is underused in the UK and there is much potential for growth.

The most significant barrier is lack of awareness and market penetration. There has been no governing body to promote ICF systems and no specific design and construction guidelines. Furthermore, there has been an absence of generic technical support. Despite the fact that ICF systems substantially outperform the current Building Regulations, particularly in relation to the revisions to Part E Resistance to the passage of sound(6) and Part L Energy efficiency(7), speculative housebuilders often operate a policy of just satisfying these requirements, rather than exceeding them.

Current market conditions are changing rapidly, with both European and British governments currently working on methods by which housing sector performance can be improved and more sustainable housing may be constructed. The revised Part E and Part L have taken effect, and EU directives on the Energy Performance of Buildings (EPBD), require transposition into UK law by January 2006. The building industry must adopt better performance standards and more energy-efficient techniques. ICF systems are gaining attention, leading to the formation of the Insulating Concrete Formwork Association (ICFA) UK.

The Insulating Concrete Formwork Association

The Insulating Concrete Formwork Association (ICFA) was officially launched on 5 September 2003, following the first generic exhibition at the launch of The Concrete Centre the preceding day. It currently consists of seven founder members (ICF suppliers, British Federation of Plastics and The Concrete Centre). ICFA UK is already affiliated to The Insulating Concrete Form Association in the USA.

The objectives of ICFA are to:

* promote ICF use in the UK

* provide a focal point for enquiries

* produce technical design guidance to encourage an integrated approach and best practice through literature, websites, exhibitions and continuing professional development seminars

* promote ICF as energy-efficient system that applies sustainable low carbon emission technology, encompassing sustainable environmental benefits

* provide a forum for networking and communicating ideas for the ICF industry

* identify and support future research and industry standard development requirements for ICF

* lobby for inclusion in the Building Regulations (Part E and L) consultation papers

* raise awareness of reduced insurance premiums whilst raising energy efficiency standards.

ICFA UK will promote an integrated approach, offering a wide selection of membership categories:

* cement and expanded polystyrene producers

* ready-mixed concrete suppliers

* pump hire companies

* contractors, builders and groundworkers

* associated materials and systems (waterproofing, renders, admixtures, internal finishes, adhesives, fibres etc.)

* equipment suppliers

* designers and engineers

* certification bodies (BRE, NHBC, etc.)

Activities already include attendance and presentations at numerous trade events such as Home Building, Renovating and Self-build Shows at the National Exhibition Centre. The Association will take a proactive stance by commissioning acoustic tests for evaluation and dissemination in relation to the Part E revisions.

The future

The use of ICF conforms with the Kyoto Protocol in the context of global change and sustainable development. To realise the full potential of ICF systems, fast market penetration is required. ICFA has developed a strategy to promote ICF and increase awareness by producing design and construction guidance and providing technical support. Lobbying for policies and standards in favour of ICF are underway. ICF use has been supported by the US Energy Bill, passed by Congress, whilst in Texas, an ICF Insurance Discount Bill has been placed on the statute book.

There is much potential for the same to occur in the UK. Research and development into more innovative ICF systems is important, such as ‘alternative’ ICF, whereby recycled EPS and cement composites are used instead of virgin EPS, thereby making ICF more sustainable. The UK Building Regulations revisions and EU directives are the current market drivers encouraging use of more energy-efficient building systems.

Concluding remarks

This is a very exciting period for ICF practitioners. Introduction of the ICFA UK should serve to increase awareness and use of this exciting system, which is fast and cost-effective, conforming to government objectives relating to sustainability, thermal and acoustic efficiency.

Meeting for new members

AN open meeting for new members took place at the Homebuilding & Renovating Show at the National Exhibition Centre, Birmingham, on 4 March 2004.

This included an announcement regarding a strategy prepared by ICFA founder members to promote ICF use in the UK. A grant application has been made to The Carbon Trust and has already passed the first round of approvals. Gaining members is vital to achieving the required funding.

Further planned member categories include ICF system providers, plant manufacturers and suppliers, installers, self-builders, supportive magazines, specifiers and companies specialising in ready-mixed concrete, pumping and admixtures.

To find out more, go to the ICFA UK website at www.icfinfo.org.uk

References:

1. WATSON, N. Expanded polystyrene – formwork for the future, CONCRETE, Vol. 36, No. 2, February 2002, pp.24-26.

2. OLIVIER, D. and WILLOUGHEiY, J. Review of ultra low energy frames -a series of uk and overseas profiles, BRECSU General Information Report 38, 1996.

3. OLIVIER, D. Energy efficiency and renewables: recent experience on mainland Europe, Energy Advisory Associates, Herefordshire, 1992.

4. INSULATING CONCRETE FORM ASSOCIATION. Concrete homes save energy (website: www.forms.org/productjnfo/brief_energy.html)

5. FUNKE, H. Underground and overground with ICFs, CONCRETE, Vol. 36, No. 2, February 2004, pp.8-9.

6. OFFICE OF THE DEPUTY PRIME MINISTER. The Building Regulations: Approved Document E – Resistance to the passage of sound, 2003.

7. OFFICE OF THE DEPUTY PRIME MINISTER. The Building Regulations: Proposals for amending Part L (energy efficiency provisions), 2003.

PAULINE GUO-HERITAGE, THE CONCRETE CENTRE AND NEIL WATSON, THE CONCRETE SOCIETY

Copyright The Concrete Society Mar 2004

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