Zinc for a HQE and BBC-Effinergie
certified secondary school
Inserted into a low density urban fabric on the outskirts of the Saint-Dizier in the east of France, Luis Ortiz secondary school is part of a larger urbanization project. The client wanted this school building to be an ecological model on a daily basis and accepted a cost increase of 16% to reach this ambitious objective.
In September 2011, 374 pupils started school in a building designed to respect both its environment and the quality of life of its users.
Designing access routes to enable pupils to be dropped off in total safety, management of movement from one part of the building to another in a spirit of progressive transition punctuated by plays of light, colours and materials: the school was designed to create an atmosphere of serenity for its pupils.
This overall environmental and performance approach enabled the school to obtain HQE tertiary building certification. Of the 14 targets comprised in this certification, the building aimed at “Very High Performance” for 5, “High Performance” for 7 and “Basic Performance” for just one. H
« This project made me more humble, more user-oriented. It taught me not to trust only techniques and calculations. Techniques contribute to the project, but are not the core of architecture. The driving factor is the users. »
VMZINC solutions used contribute to the environmental performance of the building, more specifically targets 2, 3 and 4 of the HQE approach:
Target 2 - Pertinent choice of building products:
Because they feature Fiches de Déclaration Environnementale et Sanitaire (FDES) which comply with French standard NF P01-010, and which state the environmental benefits of the long lifespan of rolled zinc (100 years) and its high level of recycling at the end of its lifespan (98.3%). Also because zinc is a durable material that requires little maintenance.
Target 3 - Low-impact building site:
Dry steam: installations without water consumption, nor emissions into the air, water or soil.
Target 4 - Energy management:
Because VMZINC facade solutions make it possible to integrate a thick layer of insulation and feature reduced thermal bridge surfaces.
Luis Ortiz secondary school also obtained BBC Effinergie certification, which guarantees energy consumption lower than 50 kWh/m2/year and greenhouse gas emissions lower than 5 kg CO2 equivalent per year.
This very high level energy performance is obtained thanks to a combination of energy optimisation strategies:
- Exterior insulation of facades to minimize thermal bridges.
- Triple glazing of all windows.
- Photovoltaic energy production of 130000 kWh/year, which covers requirements in terms of ventilation, heating and lighting, using 2 types of solar panels: 2700 m² of bituminous membrane with amorphous silicon film (mediocre performance, good price) + 350 m² of monocrystalline photovoltaic panels (high performance, more costly).
- The 7 air handling units with variable flows per frequency difference are piloted via Centralised Technical Management so that the adjustment of renewed air corresponds as closely as possible to user requirements.
- Low temperature heating is ensured via vertical geothermal energy (heat pump on water table) with under-floor heating on the ground floor and radiators on the upper floors.
Thanks to photovoltaic panels that compensate energy requirements, the school can pride itself on being a Zero Energy Building.
Thermal performance of VMZINC solutions
Optimum insulation - VMZINC systems have very high thermal performance because they enable the use of:
- All types of insulation (stone wool, glass wool, synthetic insulation, etc.)
- All insulation thicknesses, including the largest (120, 180, 250, 300, etc.)
Minimized thermal bridges - VMZINC systems have minimal thermal bridges which, according to constructive choices can easily be:
- Lower than 0.030 W/m²/year on facade (< 25% of Up)
- Lower than 0.015 W/m²/year on roofing (< 10% of Up)
What is the HQE approach?
The HQE approach is a French Environmental Quality Building approach equivalent to the LEED system in the USA and the BREEAM system in England.
This is an approach that can be used by architects wishing to design, build and deconstruct a building but minimize while at the same time optimizing the comfort and well-being of its users.
It comprises 14 targets, themselves categorised into 4 sub-sections: eco-construction (targets 1 to 3), eco-management (targets 4 to 7), comfort (targets 8 to 11) and sanitary quality (targets 12 to 14)
A building constructed using the HQE approach can obtain certification when at least 3 targets aim for “Very High Performance” and 4 other targets aim for “High Performance” (targets aiming for VHP must obtain a required minimum number of points).
What is the BBC-Effinergie label?
The BBC-Effinergie label aims to identify new buildings or parts of new buildings whose very low energy requirements contribute to reaching the 2050 objectives: reducing greenhouse gas emissions by 4.
It is defined in the French ministerial decree of 3 May 2007. The latter details the values defined in the benchmark of the EFFINERGIE association, i.e. a maximum consumption objective for new residential buildings of 50 kWhep/m²/year.
The RT 2005 thermal regulation sets objectives for air permeability of the building envelope and makes it possible to highlight a quality approach to air tightness.
The BBC- Effinergie label goes further in its requirements and enforces a measure concerning air permeability on project hand-over.