Deep renovation of St. Nicholas College Siggiewi Primary School is a good practice for achieving positive renewable energy zero carbon dioxide example.
The St. Nicholas College Siggiewi Primary School in Malta, with total floor area of approx. 4,500 m² has undergone deep renovation to attain zero-carbon emissions and positive renewable energy performance, part-financed by ERDF 2007-2013.

This is a pilot project to identify how best school buildings can be renovated. Comfort analysis using DesignBuilder-EnergyPlus software showed that for summer, the school can attain adaptive comfort if its glazing is externally shaded and night purging is introduced. In winter, mechanical passive solar pre-heating plus some active heating would attain thermal comfort level standards.

A number of measures were implemented to achieve the zero carbon status positive renewable energy building, as follows:

1. Wall insulation in selected classrooms.
2. External shading with active control.
3. Mechanical ventilation for control of carbon dioxide levels coupled with night purging in summer and passive solar heating in winter.
4. High efficiency ceiling infra-red heaters introduced.
5. Small instant electric water heaters instead of large storage systems, given the low demand for hot water.
6. LED dimmable luminaires.
7. Photovoltaic solar systems, also serving as shading overhang.
8. Solar heaters and heat pump for outdoor swimming pool plus motorised pool cover
9. BMS control and data collection system.

Resources needed

ERDF funding (including financial feasibility), dynamic building energy software simulation for identification of energy retrofit measures. Tendering and public procurement, project management including quality control.

Total cost: Approx. 2.38 million Euro

Evidence of success

Project completion and disbursements of funds on time, zero carbon emissions, positive renewable energy performance school, improvement in visual, thermal comfort and indoor air quality, reduced CO2 emissions by 115 tonnes/annum, higher awareness among the students and the general public of the benefits of combining energy efficiency with renewable energy sources.

Difficulties encountered

Challenge to reduce inconvenience to school staff during implementation. Challenge to explain new concepts and technologies to members of staff.

Challenge for installers to operate new technologies to Malta e.g. automated shading devices.

Potential for learning or transfer

The school was well studied using state of the art building energy software simulation and optimization tools so as to ensure the best measures are chosen in terms of energy reduction, thermal and visual comfort. Ongoing analysis of performance of the different energy efficiency measures will help to devise a best practice guide for retrofitting of schools in Malta. The guide should also provide ideas to renovate schools in the Mediterranean region having a similar climate.

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Main institution
Ministry for Energy and Water Management
Malta, Malta
Start Date
July 2014
End Date
December 2015


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Good Practices being followed by

Marjo Mäkipelto