Within the context of the BEEM-UP Project, ICF Habitat Novedis housing company performed the renovation of 87 apartments in the Cotentin Falguière residence in Paris, France.
The rehabilitation program includes:
- External thermal insulation of the façade (partially with BASF innovative thin insulation), the roof and the terraces.
- Woodwork replacement and mechanical ventilation implementation.
- Boilers replacement associated with regulation and performance monitoring.
- Consumption measuring and automatic reporting to the tenants.
- Implementation of an Energy Recycling biofluid system (ERS) for heat recovery from grey water to the hot water system.
The building is located in the centre of Paris. It is composed of 87 dwellings and it was built around 1950. The orientation is North and South on rue du Cotentin, East and West on rue Falguiere. All dwellings have small balconies; 7th floor dwellings have a large terrace with a view on Paris. The surrounding buildings have similar heights.
In 1993, the building was renovated (outer insulation, double glazed windows, boilers) (Figure 1), but it still needed a major upgrade: the renovation of HVAC system and the existing windows of the building was one of the major starting points for the project development. Besides, other technical and functional improvements, as well as energy demand reduction, were needed for the building to become a pilot for bringing ICF Habitat Novedis housing park to the low energy standard for the Île-de-France region for renovated buildings (less than 104 kWh/m² for HVAC, hot water and lighting).
The operation was initiated in January 2009. The main direction for the retrofitting has been selected and refined in collaboration with the design team, that was contracted in October 2009. The complete technical diagnosis is available since June 2010; works started in June 2013. Figure 2 illustrates a graphical simulation of the building after the refurbishment.
During the planning phase, six technical scenarios for retrofit have been identified (Figure 3). For all the scenarios, the building envelope is optimized with respect to the influence of the heat demand and required performance of the HVAC system. Within all scenarios the space heating demand is reduced significantly, ranging from 50% for the variant 1 up to 92% for the variant 6. In this case, the biggest share of investment is related to installation of the HVAC system. All the technology packages have been evaluated using the Life Cycle Cost approach, including the investment and operational costs (including energy and future maintenance) over its life time. According to the analysis, the technology package nr. 3 has been found to be the most economically optimal (it has the lowest life cycle cost).
Building description before BEEM-UP
Walls street side: concrete + 2 cm sandwich thermal insulation.
Walls back side: concrete + 2 cm sandwich thermal insulation + 8 cm ETICS polystyrene thermal insulation.
Roof: concrete + 5 cm thermal insulation.
PVC double glazing, 20 years old.
2 centralized gas boilers.
Sanitary hot water
Individual electric boilers for every apartment have been installed in 1993. Originally hot water was provided by a centralized boiler located on the roof.
Natural ventilation grids in the kitchen, bathroom and toilets (apparently no ventilation problems).
Common incandescent light bulbs.
Renewable Energy Source
Walls street side: +20 cm ETICS EPS polystyrene thermal insulation - λ=0,032 W/(m K).
Walls back side: New 20 cm ETICS EPS polystyrene thermal insulation - λ=0,032 W/(m K).
Basement: +10 cm EPS polystyrene thermal insulation - λ=0,032 W/(m K) below ceiling.
Roof: New 10 cm polyurethane thermal insulation - λ=0,024 W/(m K) on ceiling.
New PVC double glazing, Uw=1,5 W/(m²K).
New condensing boilers for heating and warm water.
Sanitary hot water
Focus on tenant behavior and awareness-raising during and after retrofit is expected to lead to further reductions in energy consumption.
New controlled mechanical ventilation.
ICT – energy management (including smart meters)
Cost optimal control solutions (from individual solutions like chrono-thermostat, radiator zone control, meter data for individual billing, to full home automation). Exact optimum will be defined during integration with total system and specific simulation.
All public spaces will be fitted with low-energy light systems. All tenants will be encouraged to switch to low-energy lighting.
Renewable Energy Source
Heat recuperation from waste water (ERS system) (Figure 4). Energy Recycling System ERS captures and uses again the large amount of heat that is usually released directly to sewers. This pool of heat, hitherto untapped, is used to produce hot water for sanitary applications, heating or industrial processes. System operating day and night and not dependent on the climate, it makes the need for hot water match with the available pool of heat and thus allows energy savings of 30-70% compared to regulatory consumption.
ERS has been installed in the basement of the building. In order to place the system of hot water tanks, the storage room had to be created from six existing cellars (Figure 5).
Energy consumption (data in kWh primary energy / m² net floor area / year):
Primary energy demand (for all uses): 41 kWh/m²/year
Primary energy demand for standard building: 130 kWh/m²/year
Primary energy demand of the considered building BEFORE renovation: 205 kWh/m²/year
Breakdown for energy consumption
Heating: 13 kWh/m²/year (gas)
Hot water: 28 kWh/m²/year (gas), minus the heat recovery (ERS system biofluids): 10 kWh/m²/year
Ventilation fans (electricity): 2,6 kWh/m²/year
Auxiliaries (electricity): 0,5 kWh/m²/year
Lighting (electricity): 6 kWh/m²/year
More information: Within the BEEM-UP project, the verification of energy efficiency targets is planned by measuring consumptions over one year through the center of technological resources NOBATEK. ICF Habitat Novédis also provides monitoring of consumption of the residence over the long term to optimize its usages, maintenance and check up. For this purpose, the building and equipments are equipped with Siemens sensors monitored by their intelligent control system Synco Living. The first results are expected by the end of 2014.
Average thermal transmittance of all envelope = 0,53 W/(m²K) (average value weighted respect to all envelope components surfaces)
Average thermal transmittance of all envelope BEFORE renovation = 2,12 W/(m²K)
Neopor was used for thermal insulation of the external walls (18 cm thickness) (Figure 6). This new material has been obtained by BASF improving the expandable polystyrene (EPS): graphite is added to the raw material, which gives Neopor a silvery gray color. The graphite absorbs and reflects a part of the thermal radiation, up to 20%, and improves the insulation capacity compared to that of the conventional white EPS, a density equal. Lambda thermal conductivity of 0,032 W/(mK) guarantees a thin insulating layer in favor of floor space (ideal for renovation).
On the balconies, it was decided to use an innovative insulation material developed by BASF - Aerogel boards. The material has a very good insulation performance and it is much thinner than EPS. Thanks to its properties, it was possible to save extra room on the balconies, which have very limited space, with just 5 cm thickness of thermal insulation. The solution substantially raised the quality of dwellings, keeping balconies accessible for tenants.
ICF Novedis decided to involve tenants within the whole process of refurbishment in order to make them accept the work more easily. Observations of the Paris pilot indicate that people who are engaged in the refurbishment are more aware of environmental issues and consequently contribute to the successful accomplishment of the project. Various methods have been adopted during the pre-retrofit phase, such as: employment of new person in charge of tenant interaction; individual interviews about occupation of the dwellings, assessment of housing, use of common spaces of the building and interest in the environment (72 dwellings interviewed among 87); letters to all tenants informing about forthcoming renovation plans; two meetings where general information about the retrofit project were shared; questionnaire about the technical state of the building; two workshops on specific topics (energy consumption commitment and renovation of outdoor spaces). Then, during the work period: a showcase apartment was presented to tenants at the beginning of the refurbishment; the house keeper was used as a communication channel; information website informed about the work schedule; one person from the construction company (BREZILLON) was dedicated to tenants interaction. Most tenants did not have to move out during the retrofitting work.
BEEM-UP (Building Energy Efficiency for Massive Market Uptake) is an European project, covering 3 sites (in France, Netherlands and Sweden), that aims to share innovative, economic and repeatable solutions between actors of the construction field in order to accelerate energetic renovation of collective housings in Europe. The common objectives are:
- Reduction of energy consumptions by 75%
- Establishing a quality approach enshrined in the time
- Accompanying tenants throughout the project
- Proposing innovative solutions
- Analysis of the gain of the project and its potential for replication.
The BEEM-UP project has developed and deployed a multidimensional methodology within the whole process of refurbishment in which building owners, technology providers, construction companies and researchers collaborate to demonstrate successful methods for deep retrofit with the potential for large-scale replication.
The most adequate solutions for achieving drastic energy savings involves deployment of a four-dimensional approach (Figure 7) of passive (building envelope improvement), active (ICT and HVAC systems), social (tenants involvement) and financial measures (innovative financing instruments), which go beyond 75% energy demand reduction.
BEEM-UP evaluates the performance of a large number of possible refurbishment scenarios by assessing their environmental and economic performance from a lifetime perspective.
For economic calculations a life-cycle-cost approach is chosen. It includes cost for energy, investment, current and future maintenance and other costs over the life-time of the building. Identifying Pareto-optimal solutions for the sites by the combination of possible single measures helps to exclude concepts that are less efficient than others. The focus on finding the best refurbishment variant can then be laid individually on ecologic, economic or socio-cultural aspects. Figure 8 shows as an example the performance of 729 concepts according to ecological and economic indicators. (Source: Luwoge consult)