Sustainability and the Amvic ICF System
Amvic ICF 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 few weeks 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 Ireland, 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). The operating savings in energy and thus carbon emission’s easily outweigh the initially higher carbon input used in the construction Of Amvic ICF and the system will continue to perform for decades to come.
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 manner in which polystyrene and concrete are combined in Amvic ICF construction provides outstanding performance levels for each of these key points.
Energy Savings
Insulation
Amvic ICF provides a high level of thermal insulation with a U-Value of 0.22W/m²K being achievable. By definition the insulation envelope of the building is absolutely complete when building with Amvic ICF, in contrast to all other building system which require manual site intervention to install the thermal insulation after the structure is built. In addition there is no convection loss of heat within the wall as the insulation is in intimate contact with the structure.
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.
Air-tightness
Current Building Regulations set standards for the air tightness of structures, measured using an Air Permeability Rating. A number of 10 is the required minimum with 7 being described as best practice and 3 being required for passive homes.
Because this is a poured concrete method of construction the structure is effectively monolithic, thus air-leakage is reduced to an absolute minimum. Amvic ICF is extremely airtight, with a typical structure experiencing an air permeability rating of 3 or less.
These three factors combine to produce an extraordinary thermal performance in the finished house. There are numerous testimonials from residents of homes built using Amvic ICF reporting annual heating costs of the order of €100 per thousand ft² of floor area and less, using a variety of heating media.
Durability
An Amvic ICF structure is built to last. Concrete is inherently durable, and when cast within the Amvic 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. Amvic ICF walls have certified fire-performance ratings of up to 3 hours. In addition the EPS used in the manufacture of Amvic ICF is flame retardant and both the internal and external finishing systems are certified Class A, inflammable. This means that an Amvic ICF is extremely safe and resilient in the event of a fire
Sound Insulation
The mass of the concrete within the Amvic ICF system makes for amazing sound absorption with typical sound reduction of 52 dB across the finished wall. This is far in excess of the requirements of the building regulations and makes for comfortable homes and harmonious relations with the neighbours!
Flood Resistance
ICF construction is extremely resilient to flood damage as neither concrete nor expanded polystyrene, rot or suffer from water 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 stability 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 an Amvic ICF structure safe and secure. This can be further enhanced by reinforcing the concrete where necessary.
Recyclability
At the end of the buildings – very long! – life, all of the components of Amvic ICF can be recycled and beneficially reused in other construction and related applications.