A growing phenomenon

ICF: A Global Market

ICF is taking off around the world thanks to the speed of construction, energy efficiency and design flexibility. It is used for residential and non-residential construction.

In the US over 35% of new dwellings are built with ICF – and use is growing rapidly at 5% per annum – especially in regions where hurricanes are frequent and the disaster resistant properties of ICF are so attractive.

Worldwide

$800M

Globally, the ICF market is growing exponentially and is currently worth $800million.

United Kingdom

About 4,000

It is understood that about 2% of the dwellings built in the UK are using ICF.

US Market

$200M

Leaders in ICF, the current US market is worth $200million and grows at about 5% per year.

Industrial Buildings

ICF is ideal for the construction of industrial or agricultural buildings but few if any are being built.

ICF: Revolutionising House Construction

ICF construction is certain to become a much more popular method of house building in the UK as a result of UK Government Plans for the UK Building Stock to be carbon neutral. These are now being reflected in Building Regulation changes:

The June 2022 revision of the Building Regulations is an interim measure

Required building standards will increase again in 2025

More onerous Air Leakage rules where ICF is so superior to all other systems

Measures to prevent Overheating that is significantly increased by the lack of Thermal Mass in Timber Frames and SIP will drive more users to ICF

stone-finish-house-built-in-insulated-concrete-formwork

ICF, Timber Frame or Cavity Walls?

In the UK the use of Insulated Concrete Forms (ICF) construction is limited to self-builders and a few developers but this is likely to change rapidly in the near future are the building industry gets to understand the unique properties of ICF construction.

How much does it cost?

Dwelling Walls cost about 23% of the Total House Cost.

ICF costs about 15% of the total Wall Cost

Or, about 3.5% of the Total House Cost

Increasing Labour Costs

Builders who don’t move from traditional construction methods are likely to see labour costs increase exponentially. For instance, soon they will need to prove with photographs that the cavity walls comply with the Regulations – every Builder will be painfully aware of how much extra supervision this will require.

Reduced Workforce

To make matters even more difficult, the UK construction work force is reducing by 50,000 to 60,000 people per annum. And less than half of these are being replaced by apprentices.

A Cost Comparison

ICF

✓ £60 – £70 /m2 + cost of concrete + labour

✓ 10 days with semi-skilled labour to build up to eaves level

Timber Frame

✓ £80 – £100 /m2 + labour

✓ 2 weeks for a quote and over 10 weeks for delivery

Cavity Walls

✓ 50% of total cost is labour (£75+ /m2)

✓ 2 months to reach eaves level using skilled labour

Cavity Wall Disadvantages.

Cavity wall construction is a common method used in building exterior walls which involves two separate walls (known as leaves) with a gap or cavity between them. While cavity walls have several advantages, they also come with significant disadvantages:

Moisture penetration can result in internal damp patches and mold growth. In severe cases in exposed locations or in high buildings, wind driven rain penetration can cause wall tie corosion and eventual structural failure.

If mortar accumulates on brick ties through carelesss workmanship thermal bridging will increase heating costs.

Wet insulation does not work well and any gutter problems can result in very wet walls and severe heating loss.

This is one of the problems that always occur when poorly trained bricklayers are let loose on a site and can cause severe long term moisture penetration and thermal bridge heat losses.

If any problems do occur after completion it is extraordinairly difficult to inspect the cavities and plan repairs.

The tragedy at the Grenville tower has resulted in much greater scrutiny of the potential spread of fire in cavities. It is vital that the cavity wall areas are separated from the walls of the adacent apartments and this requires a lot more supervision and it dramatically slows down the work.

There is no doubt that building cavity wall houses is a very slow process that needs good weather. Wet or cold weather stops the bricklayers and this time can never be regained because getting the building weathertight is always on the construction critical path.

Before the June 2022 changes to the Building Regulations air leakage tests were not required. Now, every new dwelling has to be tested for air leakage and they can be very difficult to locate in te event of a failure.

Timber Frame Disadvantages.

Timber frame construction is a method that uses a frame of large wooden members to form the structural skeleton of a building. It has gained popularity due to its sustainability and efficiency. However, it also has some disadvantages that need to be considered:

Mortgage companies and the NHBC require a 60 year design life to accept timber frame construction. This can only be, because the timber frame industry in the UK is huge and has a major say in the development of the Building Regulations. It is commonly accepted that the life of treated softwood is no more than 20 years and so hundreds of thousands of homes are going to need to be demolished in the next 20 years. Just make sure that you do not own one!

Fires can only burn when they have fuel and timber is a fuel whereas concrete is not. In the recent forest fires in Los Angelese, ICF houses remained standing surrounded by the charred remains .of their neighbours homes.

.All kinds of insects adore living in and eating wood! Concrete does not suffer from this!

Timber is a lot less strong than prestressed concrete and makes large rooms difficult to accommodate.

Timber shrinks, leading to issues such as uneven floors and cracks. in the wall plaster.

The only thing that stops noise transmission is mass and a typical ICF concrete wall 200mm thick is deemed adeqaute to stop noise transmission between adjacent dwellings on the same floor. .Timber walls need to be much wider with a very thick layer of insulation to even approach the same noise reduction standard.

Regular painting and sealing. is essential for all timber framed dwellings.

In the medium to long term there will probably be a lot of timber framed houses being demolished because of rot. The market value of timber frame buildings will then probably drop a great deal because it is very difficult for a surveyor to see and identify any rot inside the plastic membranes that are designed to keep moisture out but actually trap it inside the wall!

Timber is a renewable resource but the lack of thermal mass in a timber framed house will susbstantially increase heating and cooling costs.

Whereas ICF can be finished very quickly and cheaply using acrylic render the finish options for timber frame buildings are often expensive to both buy and install.

ICF Construction

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