Case Study: nZEC - Energy refurbishment of 122 dwellings in the residence Le Provence, Port de Bouc, France
Name of organisation: Logirem
Stage of development: completed
Year of finalization: 2014
Type of project: refurbishment
Area: urban
Scale: group of buildings
Type of building: Apartment in a block of more than ten stories
Number of units/dwellings: 122
Tenure: social rental
Street: 6, Rue de la République
Postcode: 13110
City: Port de Bouc
Region/ County: Provence-Alpes-Côte d'Azur
Country: France
Last Update: 17.04.2015
Short Description
This project entailed the refurbishment of the following three buildings:
Building A: 11 floors, living area: 3161 m²
Building B: 14 floors, living area: 4155 m²
Building C: 4 floors, living area: 1304 m²
Total living area (3 buildings): 8620 m²
Total net floor area (3 buildings): 9482 m²
Key Elements
Funding
The following fundings for the global cost of the constrution are pending:
- Regional fundings: 10% of the global building cost;
- Ademe (French energy agency) (Funding for the production of heat produced from renewable sources): 2,7% of the global building cost;
- Request for proposals from ERDF + Ademe + Region : 25% of the global building cost.
The Ademe (French energy agency) financed a part of the energy audit (7 074,34€).
Construction overall | TOTAL: 2 767 598,72€ all taxes included (Construction + Fees + Updating and hazards) |
Building services | Masonry lot (including floor insulation): 152 475€ all taxes included Water tightness lot: 113 366,5€ all taxes included Frontage, external insulation, coating: 749 588,5€ all taxes included Electricity lot: 187 224,32€ all taxes included Plumbing, heating and ventilation lot: 556 688,9€ all taxes included External millwork lot: 35 898,5€ all taxes included Metal work lot: 287 808,60€ all taxes included Internal painting and floor lot: 65 344,9€ all taxes included Lift lot: 320 465€ all taxes included Internal millwork lot: 48 738,5€ all taxes included Fees: 150 000€ all taxes included Updating and hazards: 100 000€ all taxes included
TOTAL: 2 767 598,72€ all taxes included
RENEWABLE ENERGIES – If it is validated Prices without taxes Thermal solar panels (79m²): 100 641,20€ |
Low/zero carbon technologies | Solar installation: 100 641,20€ without taxes Installation composed by 79m² of thermal solar panels |
VAT | 7% |
Running costs | Annual consumptions Before refurbishment: Electricity for common parts including lighting, lifts, pumps of the heating system and ventilation (final energy): 31 024 kWh / 2 171,68€ all taxes included Gaz (higher heating value): 1 116 642 kWh / 55 832,10€ all taxes included Expected after refurbishment: Electricity for common parts including lighting, lifts, pumps of the heating system and ventilation (final energy): 31 024 kWh / 2 171,68€ all taxes included Gaz (higher heating value): 214 838 kWh / 10 741,90€ all taxes included
SAVINGS: Concerning the possible savings, the following projections were calculated: Without solar panels: Saving of 5,25€/m²/year With solar panels: Saving of 6,15€/m²/year |
Certification
The objective of the operation was to reach a level of consumption of 40 kWh/m²/year, which corresponds to the level of low energy buildings for new construction.
An energy audit was carried out at the very beginning of the project in order clearly define the objectives and the priorities. Logirem is also engaged in a sustainable development policy as signatory of a charter developed in the South-East of France for building and retrofitting operations and member of the sustainable Mediterranean building label. The two documents were included in the contractual documents of the project management.
On a scale from A to G, the level of the building before refurbishment was D, with an annual consumption of 164 kWh primary energy/m². The objective of the refurbishment was to divide the consumption by 4 and to reach 40 kWh primary energy/m² (level A).
A: <50 kWh/m².year, B: 51< <90, C: 91< <151, D: 151< < 230, E: 231< <330, F: 331< <451, G: >451
Thermal Insulation
In terms of thermal insulation of the buildings, it was decided to set up an external insulation on the façades (thickness of 15cm). A special focus was set on the draughtproofing of windows with seal and the finishing work around the windows. The terrace roofs were also insulated (thickness of 12cm) as well as the floors of the ground floor flats (thickness of 10cm).
Heating and Hot Water
The replacement of the radiators in all the dwellings with the setting up of thermostatic valves was included in the operation as well as the desludging of the hot water supply system. Before the refurbishment, two boilers provided the required heat; the oldest one was replaced by a condensing boiler.
Solar Thermal
The installation of solar panels for the production of the domestic hot water was studied and will be validated if the project is laureate of the ERDF request for proposals.
Work with Residents
Logirem had already worked on the engagement of residents for another operation. This work had been led by the association Ecopolénergie. The objective for the operation on the residence Provence is to reuse the tools developed previously and accompany the tenants for an appropriate use of water and energy.
Water Saving
Water saving flushes toilet replace the old ones. Flow restrictors are installed on the new mixing valves, as well as water saving showers.
Main Results
Concerning the possible savings, the following projections were calculated:
- Without solar panels: Saving of 5,25€/m²/year
- With solar panels: Saving of 6,15€/m²/year
- 79m² of thermal solar panels could be installed installed on the roof of the building where the boiler room is located, to ensure a preheating of the domestic hot water.
The level of energy consumption of the building before refurbishment was 164 kWh/m²/year (level D). The expected level of energy consumption of the building after refurbishment is 40 kWh/m²/year (level A). A division by 4 of the consumptions was aimed at for this operation.
Lessons learned
In terms of performances, this project aimed at decreasing the energy consumptions, and thus decreasing the invoice for the tenant and decreasing the impact of the increase of the energy tariffs to come. In exchange of this decrease of the energy expenses, a financial contribution is asked to the tenants through an increase of 5% of the rents.
Additional Information
Ms Carine Puyol
USH - The French Federation of Social Housing Providers
E-mail: carine.puyol@union-habitat.org
Web: www.union-habitat.org