The Downs National School – Transformed into an energy-efficient building

Project Description

The project, part of a pilot programme, comprised of two goals — retrofit and extend, according to nZEB standards.

It consists of the low-energy retrofit of the existing 3-classroom school (254msq), and the construction of an adjoining single storey 4-classroom extension to the existing school (441msq).

This project aims to achieve high energy efficiency and is employing complex construction methods to achieve this, such as building fabric upgrades, new ventilation, and heating system.

The Challenge in Work

This pilot project, the second of 2 schools and 4+ years in development for the department of education has ambitious targets and detailed external monitoring.

From the beginning, Partel technical team worked closely with Connelly Builders and ORS construction specialists to develop an efficient airtightness and ventilation design strategy for the deep energy-retrofitting of the building, to meet the final energy levels of the project.

The school has been equipped with Partel airtight building envelope systems and LUNOS decentralised ventilation units with heat recovery.

The breathable roof system – VARA PLUS smart vapour barrier, EXOPERM MONO fire resistant monolithic membrane, CONEXO and CONIZO airtight tapes – was chosen to provide maximum protection to the roof, and to be part of a system that would not contribute to condensation like many school projects suffer from.

Fairfaced blockwork was used for airtightness in combination with the Partel system but a movement joint presented an obstacle – one the CONPRESeal tape was able to assist with. CONPRESeal joint sealing tape was used in some blockwork movement joints to prevent air leakage.

Partel EXOPERM MONO – Monolithic Breathable Membrane


Partel VARA PLUS – Smart vapour control layer



Partel CONEXO Airtight Adhesive Tape


Lunos Nexxt units require very little operating energy and work at a particularly low noise level – very quiet – thanks to their intelligent design and the radial ec motors. The enthalpy heat exchanger achieves a heat recovery rate of up to 83%.

LUNOS Nexxt Ventilation Units with Heat Recovery


Classrooms are now supplied with constant fresh air via a heat exchanger by extract air, with CO2 monitoring and control. Fresh air can enter and odours and excess humidity are eliminated. This also actively prevents the formation of mould.  The LUNOS Nexxt units have integrated humidity controls, connected CO2 sensors but in this case, they also had to be connected to a BMS system. This made an efficient ventilation plan necessary and a solution was found through LUNOS technical support.


Project Completion & Details

This project completed in 2019 is airtight with super insulated fabric and provides improved indoor air quality. At the same time, reducing the amount of energy used in schools is reaping the benefits of reduced energy bills.

Project Type: Low-Energy Retrofit
Location: Co. Westmeath, Ireland
Building: School
Consultant: ORS
Builder: Brian Conneely & Co.
Completion: 2019




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