Sustainability and the Reward Wall ICF System
Reward Wall Systems take environmental issues very seriously.
We believe the Reward ICF system to be a cost effective method of construction that is more sustainable and environmentally friendly than standard masonry or timber frame.
“Sustainable development is... development that meets the needs of the present without compromising the ability of further generations to meet their own needs.”
- World Commission on Environment and Development, Our Common Future, 1987
There are 3 elements to sustainable development: the economic, the environmental and the social. Sustainable development is about finding a balance between these three and considering all three at every stage of the project.
Sustainability decisions must consider the lifetime of a building however, not just the initial impacts.
So how is ICF sustainable?
Embodied Energy
Concrete, a major element of ICF construction, hasn’t traditionally faired that well in ‘Eco’ terms because of the high amount of energy needed to produce cement. However, recent developments in concrete technology has changed this, for example, a typical structural concrete mix using 50% ground granulated blast-furnace slag as a cement replacement now has embodied CO2 in the order of just 12% of what would have been the original 100% cement figure.
Similarly, expanded polystyrene (EPS), a natural by-product of the petroleum refining process and the other major element of ICF construction, when used for insulation purposes will recoup the CO2 generated during its production within the first week of the building's operation, simply by reducing occupant heating/cooling demands. EPS is also HCFC and CFC free.
But as mentioned earlier, sustainability decisions must consider the lifetime of a building and not just the initial impacts.
In the UK, 10% of our CO2 emissions come from the construction of our built environment. But a massive 50% comes from actually using our buildings, 27% of which is residential use.
And this is where ICF construction really comes into its own, both in terms of its durability and its energy-efficiency, proving that it is a truly sustainable modern method of construction (MMC).
Lifetime Savings
The following points are considered as key aspects to consider when developing sustainable construction:-
- Thermal Mass
- Durability
- Fire resistance
- Acoustic performance
- Flood resistance
- Maintenance
- Security
- Air tightness
The way in which polystyrene and concrete is combined in ICF construction means this system provides outstanding performance levels for each of these key points.
Thermal Mass
Concrete construction naturally has a high thermal mass, which is the ability of a material to store excess heat energy during the day. This heat energy is then released back into the building at night as it begins to cool. The strength of an ICF construction allows for concrete elements to be used internally throughout, including all floors and internal walls, maximising the thermal mass available.
Durability
A Reward ICF structure is built to last. Concrete is inherently durable, and when cast within the Reward ICF system, it cures without suffering exposure to extreme temperature variances. This results in a far higher strength of set initially, but the insulation provided by the polystyrene also permanently reduces the stress on the concrete caused by thermal expansion and contraction, enhancing its lifetime well beyond standard masonry construction.
Fire Resistance
Concrete construction is extremely resilient to fire damage. Reward ICF walls have fire-performance ratings of up to 4 hours.
Sound Insulation
The mass of the concrete within the Reward ICF system makes for amazing sound absorption with typical sound reduction of 52 dB across the finished wall.
Flood Resistance
Neither concrete nor expanded polystyrene rot or suffer from water damage, making ICF construction extremely resilient to flood damage. The monolithic structure is much better at resisting water ingress and can even be made waterproof for applications such as basements and swimming pools.
Maintenance
The physical and chemical constancy of both concrete and EPS in an ICF building means there is practically no maintenance required to the structure at all.
Security
The inherent strength of the solid concrete core makes a Reward ICF structure safe and secure. This can be further enhanced by reinforcing the concrete where necessary.
Air-tightness
Reward ICF is extremely airtight, with a typical structure experiencing less than 1 air change per hour (ACH). Because this is a poured concrete method of construction the structure is effectively monolithic, thus air-leakage is reduced to an absolute minimum.
ICF - a Modern Method of Construction
“I can confirm that ICF fall into the 5th Category of MMC, which is called ‘Non-OSM MMC’. This category includes building systems with advanced on-site processes, where traditional components are combined in innovative ways.”
“The information you have provided previously about ICFs indicates that this ‘innovative combination of components’ leads to fast build times and excellent insulation standards. Thus ICFs can be classified as MMC.”
- The Housing Corporation, writing to The Concrete Centre to confirm the status of ICF as an MMC. Reproduced with permission.