Courtesy : constructions21.org

Green Factory building

This building was awarded the Sustainable renovation Grand Prize of the Green Solutions Awards 2020-21 at the international level; and a mention for the same category at the national level.

Located in the former industrial suburb of Lyon, which has been undergoing major changes since the 1990s, Green Factory is a mid-twentieth century building combining a steel frame and concrete structure (posts & beams & ribbed slab). The building was poorly insulated, very energy consuming and not cooled. It was connected to a collective gas boiler room for part of the premises, with additional electric convectors in the offices. It had been disused for several years because it no longer met the comfort and energy criteria that are the norm today. Its roof was made of asbestos cement and rested on a metal frame hidden by a false ceiling. The premises were poorly lit and unattractive and not accessible. The height under the roof varies from 5 to 6.50 m on the first floor and 3.50 m on the ground floor. The building has a floor area of approximately 3,000 m2 on two levels.

This rehabilitation is part of a global sustainable building approach that meets the challenges of the coming decades. Social and health issues, the impact on the local economy and the environment, and CO2 emissions are considered with equal value, considering that the construction world should be anchored in a more systemic approach.

The cultural dimension is present in the project. It is reflected in an architecture that preserves and enhances the industrial past of the Vaise district. This district of Lyon has undergone massive restructuring over the last few decades. Its industrial heritage has been erased in favour of new buildings that meet contemporary standards. Preserving the history of the area was one of the challenges of this project. The history of the district will be retraced in the common areas of the building.

Some figures after rehabilitation:

– Ceiling heights of 5 to 6.5 m on the first floor and more than 3.2 m on the ground floor, a heated and cooled volume of more than 12,000 m3, in line with the desire to leave the old framework visible.

– An energy saving of more than 60% compared to the initial situation (heating only) including heating and cooling. For the regulatory uses, the estimated consumption is 62 kWhEP/m².an, i.e. -29% compared to the requirements of the BBC renovation label, i.e. less than 9€ +- / m2 .an with a Kwh at 15 c excluding subscription, with an average ceiling height of more than 4 m Heating alone represents 13.50 kWhEP/m².an.

– The heating and cooling of this large volume is provided by a thermodynamic double flow ventilation (CTA). This AHU is coupled to a heat pump, and the air is diffused by perforated ducts. The perforated ducts with MIX-IND® technology, also called PULSEURS®, do not “throw” the supply air into the zone to be treated, like all diffusers, but create on their axis a “pressure field” capable of putting in controlled movement the whole mass of ambient air. Online monitoring of consumption is available to users.

– CO² emissions are reduced by a factor of 20: 2 kgCO2/m².year in the operating phase.

– Air permeability (Q4pa-surf in m3/(h.m²) is 1.14 (reference value is 1.7 for this type of building).

– An air quality approach with the installation of sensors with an e-mail alert system (fine particles, noise, hygrometry, temperature, CO2). Educational support is offered to users for the interpretation of measurements and to propose corrective actions. The double flow ventilation unit is equipped with a filtration of the incoming air and a plate exchanger to avoid recycling the indoor air (reduction of virus diffusion).

– x 2 of the initial glazed surface, i.e. 14% of glazed surface in relation to the thermal floor area (shon RT), including the creation of a central glazed patio for access to natural light and user enjoyment.

– 160 m3 of hemp and flax insulation and 90% French-made products and equipment

– Recycled materials (acoustic panels, terrace floor and social areas)

– More than 1500 m2 of restored and preserved steelwork

– More than 20 local companies and design offices

– 1 NF tertiary building label associated with the HQE peqa approach (7 associated qualities) + BBC renovation in the process of being awarded, as of 20 March objectives achieved and exceeded.

– Nearly 3,000 m2 of flexible surface area that can be adapted without major transformation

– 1 quality of use and educational approach: comfortable and bright social spaces (two comfortable terraces), electric vehicle charging points. Online access to energy consumption and air quality. A building accessible to all thanks to two facilities (PRM platform and lift).