Low Running Costs – This is achieved when insulated Concrete Forms are used to build the structure as they offer low ‘U’ Values from 0.3W/m2degk, down to 0.11W/m2degk and they actually perform to their ‘theoretical calculated design performance’ unlike most materials where a lower U value simply means an improvement on previous. Because dense concrete is the structural core and the layer of insulation is much thicker on the outer leaf (in the lowest U value requirements), “thermal mass” benefits are obtained which means that the building is warm inside when it is cold out-doors in winter and vice versa in summer. This means that you can turn your heating on later in the year and switch it off earlier. Because there is better retention of heat within the building, you are able to use a small boiler than you would have to had the structure been built out of lightweight materials and in some cases – Passiv Haus Design, a boiler will not be required at all.
As summers in the UK get increasingly warm, air-conditioning will increase but thermal mass will minimise the need for air-conditioning offering further savings against lightweight framed structures not yet taken into account by regulation but coming soon!
Good Acoustic Performance – Due to the density and thickness of the concrete cores within the ICF’s, excellent acoustic insulation is provided, well below the current Building Regulations Part E. Currently (November 2007) pre-completion tests are required since no Robust Details are in place for ICF’s but to date all tests with all ICF systems have passed the Building Regulation requirement.
Healthy Indoor Environment – An ICF structure will have minimal air leakage as it is a monolithic structure. North American experience demonstrates that occupants with allergies and chest complaints have minimal difficulties caused by dust, pollen etc, within the property than competitive house building systems.
Fire Resistance – All Insulated Concrete Formworks provide fire protection in excess of normal requirements. EPS (expanded polystyrene) is manufactured containing a fire retardant substance, which means the ICF does not support a flame.
Minimal Flood Damage – Concrete and construction grade EPS are unaffected by water. If ICF buildings are in an area which is subject to possible floods, they will with stand the pressure of water and flood damage will be minimised especially when compared with building methods. ICF properties exposed to water can be pumped and dried out leaving the structure integrity unaffected.
ROT and Vermin – ICF structures do not rot and are unaffected by vermin and termites.
Wind Storm & Earthquake – ICF’s developed in North America as basement constructions providing successful protection from heavy storms and high winds including hurricanes and tornadoes. As market share grew ‘above grade’ there have been numerous examples where ICF houses have stood unaffected whilst lightweight framed structures have been completely destroyed. Since ICF’s are concrete framed structures, they can be designed to the relevant codes for earthquake zones.
Mortgage, Insurance and Planning Acceptance – ICF structures – concrete framed buildings – are accepted by all reputable companies and organisations providing they have passed the recognised third party tests and standards that are needed to obtain building approval. In the UK ICF’s should have either BRE or BBA certification and ready-mixed concrete should be supplied from manufacturers offering BSI or QSRMC Quality Assurance schemes. They should not be described as ‘plastic houses’ to lenders as this will lead to rejection!
Easily Adapted for Future Needs – Because concrete frames offer a whole floor space without further loadbearing walls, it is easy to remodel and upgrade floor layouts in the future. The strength of ICF walls allow extra floors to be added subject to authority approval and it is easy to add and tie in future extensions. The structural walls also will accommodate extra openings in the future, though engineering approval would be needed. If even lower U values are required in the future, extra polystyrene could be fitted externally and reclad.
Minimal Maintenance Required – Under normal circumstances no maintenance would be required on the ICF walls in the life of the building. The internal and external facades could be subject to minor damage which be easily repaired or completely stripped and renewed.