The publication in September 2013 of the new Building Code in its section on Energy Saving ( CTE DB- HE), in force since March 14 , has lead ANDIMAT ( National Association of Manufacturers of insulating materials ) to publish a series of case studies that aim to help the technical people responsible for justifying compliance with the new CTE HE1 .
The cases show the difference between the calculation of the energy demand for heating and cooling of a particular building in accordance with the requirement of the Simplified Option of CTE 2006 and the pre-dimensioning based on the guidance values in Appendix E of the CTE 2013.
A block building in climate zone C
One of the cases proposed by ANDIMAT is a block building with seven plants, located between medians. The climate zone considered in this case is Area C, namely the C2 zones (Barcelona, Gerona, Orense) and C1 area (Bilbao , Cuenca , Coruña , Oviedo, Pontevedra, San Sebastian, Santander) are analyzed. These two climatic zones represent 24 % of the housing stock.
The main findings of this case are:- The facade insulation triples, the insulation doubles in covers, in soil it increases by 40 % while the insulation capacity of facade voids doubles. – These increases will be greater if thermal breaks are not adequately addressed. – The extra cost is around 35 % (about 12.3 € / m2) - Energy saving is increased by 35 % for C2 zones and above 45% for the C1 areas. – Investment is recovered in just over 6 years. – In 50 years of life of the building and assuming a 2% increase in the cost of energy per year, at least 12 times the investment will be recovered in the C2 area and more than 18 times in the C1 zone.
These cases confirm what is indicated in the first case study: the new CTE HE1 2013 significantly increases the demands for the envelope, the extra cost is perfectly acceptable and it becomes a quite profitable investment.
A block in climate zone D
In this case the idea is to show the differences between the calculation of the energy demand for heating and cooling of a building in accordance with the requirements of the Simplified Option CTE HE1 2006 and a pre-dimensioning based on the guidance values in Appendix E of CTE HE1 2013. The climatic area considered in this case is the D3 area.
The ROI is produced in two years since the annual savings are € 4,391 for the building and 182 € / year per housing, making that after 50 years the savings obtained are € 9,148 /housing assuming that the cost energy remains unchanged .
Building (CTE) DB- HE1 of 2006 compared to 2013 results in a reduction of energy demand for heating of 50%. The facade insulation necessary triples, the insulating capacity of the facade voids doubles, the necessary isolation in soils increases by 50% , the required insulation in cover doubles and the building envelope insulation improves.
The implementation of the CTE 2013 CTE compared to 2006, results in an increase of 30% in energy savings, investment resulting from the application of CTE 2013 instead of CTE 2006 is amortized over two years and in 50 years of life of the building, the investment will have been recovered at least 40 times.