National Home Retrofit Scheme

What is an extensive home energy upgrade?

Deep retrofit is just another term for an extensive home energy upgrade. There are multiple benefits to carrying out a home energy upgrade. It will result in a warmer, cosier home with an improved BER rating. Research has shown that a warmer home also benefits overall health and wellbeing. Since your home will be much more energy efficient, your heating bills should also be lower.

A deep retrofit takes a whole-house approach to energy in the home. The aim of a deep retrofit is to achieve a BER A-rating. This is involves carrying out multiple energy efficient measures together. Wall insulation, attic, replacing windows and doors. looking at air tightness and ventilation. Deep retrofit also looks at installing renewable energy technologies in the home.

To complete a deep retrofit project, a lot of work will be undertaken in your home. In some cases, the level of work might feel similar in scale to an extension being built to a property.

Wall insulation

Why install wall insulation?

Up to 35% of your home’s heat can be lost through your external walls. This heat loss can be reduced by insulating the walls so that more heat is kept inside your home. There are three different ways to insulate your walls; cavity, external and internal wall insulation. These can be used on their own or in combination depending on your existing wall construction. Additional internal ventilation is needed when your walls are insulated. Your contractor will assess the best method and discuss this with you before the work begins.

Cavity wall insulation

If your home has cavity walls which are not insulated, or only partially insulated, then cavity wall insulation is an easy, cost effective first step to reduce heat loss. If your home has a cavity wall, insulation is pumped into the cavity. A series of small holes are drilled in the wall, at regular intervals, on the outside. The insulation is then pumped into the cavity through these holes, and the holes are filled in so that they match the rest of the wall.

External wall insulation

For solid block or concrete walls with no cavity, external wall insulation is generally the preferred option. It can also be used in addition to cavity wall insulation to further improve the performance of your external walls. External wall insulation involves wrapping a layer of rigid insulation around your home, fixing it to the walls, embedding mesh in it to provide strength, and covering it in a render to provide weather resistance.

Internal wall insulation

Internal wall insulation might be recommended for your home because it has solid or cavity block walls, and external insulation is either not possible (i.e. for some protected structures) or is not considered the best solution.

Internal insulation (sometimes referred to as ‘drylining’) usually involves fixing insulation boards to the inside of the external walls and covering them with a vapour control layer, plasterboard, skim and new painting. As the boards are applied to the inner side of the walls, there will be some loss of space in the rooms.

Attic insulation

As heat rises, up to 30% of your home’s heat can be lost through your roof. Insulating your attic space keeps the heat below the ceiling and in the rooms below, thus reducing heat loss.

If you have an attic, a thick layer of insulating material will be rolled out over the ceiling below. The water tank and pipework will also need to be insulated, and a walkway and ventilation provided. It is also possible to insulate sloping ceilings or flat roofs where necessary. With the new insulation, proper attic ventilation is very important; it reduces the risk of condensation build-up in the attic space, which can reduce the effectiveness of your insulation and cause damage to your roof structure.

Floor insulation

Up to 10% of your home’s heat can be lost through your floors. As with attic and walls, this heat loss can be reduced by insulating the floors so that more heat is retained inside your home. However, upgrading the floor insulation may not be not possible in all homes as the level of disruption is dependent on the type of existing floor construction.

Different approaches will be needed depending on whether you have a solid ground floor, a suspended concrete floor or a suspended timber floor. In some cases it may be possible to lay insulation on top of the existing construction or in other cases it will be necessary to fit insulation to the underside of the concrete or timber structure.

Window and door upgrades

You can lose about 10% of your home’s heat through your windows and doors depending on the age of your existing windows. If you’ve got well insulated walls and attic, then the heat lost through poorly performing windows and doors will be even greater. Generally, replacement to current standards will be required as part of the deep retrofit to meet the minimum energy rating.

During the pre-works survey, your contractor will measure the windows and doors to be replaced. Once the specification and costs are agreed, the contractor will then send the dimensions to the supplier so they can be manufactured. The standard waiting time is around 4-5 weeks from order to installation of the new windows and doors.

Ventilation systems

Proper ventilation improves the air quality in the home. It is very important for both the building’s health and the occupant’s health. As the overall airtightness of your home will be dramatically improved as part of a deep retrofit, ensuring that there is good ventilation is even more important – to improve the indoor air quality and reduce the possibility of any condensation or mould.

If your home is going to be fully insulated and new windows and doors are going to be installed to eliminate draughts and air leakages, then a new ventilation system will be required as part of the deep retrofit. Typically, either a Demand Control Ventilation (DCV) system or a Mechanical Ventilation with Heat Recovery (MVHR) system will be required.

What difference will I notice with a new ventilation system?

• Proper ventilation removes stale air and odours and ensures that fresh air is circulated throughout your home at all times. This does not mean that your home will be colder or draughty, but the warm air will not be harmful for your health.
• You may be able to hear air coming in through the vents, which is normal. If you choose, and when the weather permits, fresh air can also be provided naturally by opening a window.

Wood-burning stoves

Modern room heating stoves are highly efficient when compared to a traditional open fire as they provide three times the heat and use only a quarter of the fuel. A wood burning stove with a minimum efficiency of 70% may be considered an appropriate element of the whole house solution that is proposed for your home.

The installation of the wood burning stove can be carried out within a single day, usually by two persons. As well as removing the existing fire grate and surround, it will be necessary to install a new metal flue liner in your existing chimney.

Renewable energy systems

If you are getting a deep retrofit with SEAI, your project must include a renewable energy technology. This will support the transition away from fossil fuels. Renewable energy systems provide heat or electricity to your home without the need to burn fossil fuels and are generally required in order to achieve an A-rated home. There are a wide range of renewable energy systems currently available on the market with the most prominent to date being heat pumps, solar water heating panels and solar photovoltaic panels.

Heatpumps - why get one?

Older gas and oil-fired boilers are wasteful of energy and costly to run because of the amount of fuel needed to maintain adequate comfort levels and hot water in the home. Replacing a conventional heating system with a heat pump system can transform the comfort levels in your home while reducing running costs, energy usage and harmful greenhouse gas emissions. As part of a deep retrofit, the heat pump system will eliminate oil and gas bills from your home.

There are a number of different types of heat pump systems; air source, ground source and water source. The most common heat pump systems extract heat from external air, typically using an outside unit. These heat pump systems do not require underground piping to source heat and so are easier to install as part of a retrofit project. Air to water heat pumps are the most popular choice of system. Heat is distributed through radiators or underfloor heating and they can also produce hot water. As heat pumps operate with lower temperature water the installation may require the replacement of your existing radiators to low temperature radiators. The new system will have a range of different controls i.e. time and temperature regulation and you will be able choose which areas of your home you wish to heat at any time.

Solar panels

Even in Ireland’s climate, solar energy can contribute to your home’s energy requirements. Solar energy can be used to generate electricity or for water heating. Solar photovoltaic (PV) generates renewable electricity from the sun, which can be used to power all electrical devices in your home, such as your kettle, fridge, shower and TV. Solar thermal collectors will also reduce the amount of energy needed to heat your water, by supplying hot water to your hot water cylinder.

What's involved?

Most of the works will take place outside the home as the solar panels will generally be installed on your rooftop depending on the orientation of your house. There are some planning restrictions on the size and positioning of domestic solar panels to be taken into account as part of the pre-works survey. The condition of the existing roof will also need to be considered. In the case of solar thermal panels it is likely that you will require a new hot water cylinder which will be bigger than your existing cylinder so there may be reduced space in the cupboard / room where this is located. This will be discussed with you as part of a pre-works survey.