A deep retrofit of this 1970’s Wicklow bungalow has transformed it into a contemporary, low carbon home, bringing it from a BER E1 to A2.


  • A-rated home
  • Minimised heat loss
  • Renewable energy available

Key achievements

BER A2 achieved

The works achieved a BER uplift from E1 to A2


Installed renewable energy technology

Installed an air to water heat pump to replace an oil boiler


Comfortable and warmer home

They homeowners now enjoy a much warmer, cosier and healthier  environment

Reduced running costs

Financial and energy savings are expected to reduce significantly, with initial calculations due in September 2020


SEAI’s Deep Retrofit Pilot Scheme

The SEAI grant programme was launched in 2017 to investigate the challenges and opportunities of deep retrofit in Ireland. The Deep Retrofit of a home means carrying out multiple energy upgrades all at once to achieve a BER of A-rating. The findings to date are informing our approach towards a large-scale deep retrofit of our housing stock. We are committed to sharing learnings from the pilot programme and we hope our case studies will help you understand better the measures carried out and the resulting uplift in the BER.

About the Project

This detached bungalow in Rathnew, Co Wicklow  built in 1973  was a typical build of this decade - fossil fuel reliant, with little insulation and low performance windows and doors. Before the project started, this home had a building energy rating (BER) of E1.  

The initial phase of the deep retrofit involved thorough insulation of the external walls, ceilings and of the suspended timber floors.Sustainable energy installations in this phase included the fitting of high performance triple glazed windows and a composite door to keep the heat in. Insulation is the first and most important step of the retrofitting process. The next phase included installing and integrating renewable technology to decarbonise the home.

The provision of heating and hot water via an air to water heat pump replaced the old oil boiler.. The integration of mechanical ventilation with heat recovery resulted in improved air quality  for the homeowner as well as reducing carbon emissions and household costs. A highly efficient wood burning room heater replaced the multi-fuel stove and 100% LED lighting were installed throughout the home.


The bungalow received a post works BER of A2, making it highly energy efficient.

There was a significant level of disturbance and upheaval for the occupants of the home because they effectively had to gut, replumb and rewire the entire house, with the works ongoing for just over five months from start to finish. The project had to be completed within a certain timeframe  to meet the deadline for the retrofit grant.


“The benefit to us is taking the house from an E1 to an A2, and in terms of energy savings it has been really good. We have now gone from having a combination of bottled gas, oil and electricity, to just electric which has been superb. I have to say the house is  unrecognisable, , it’s like having a new house. It’s the sheer benefit of now living in a modern A2 house” - The Homeowner.