Power cut: How to reduce your energy costs

Doing some work on your home now will significantly lower those ever-spiralling utility bills

Attic insulation: 300mm recommended

Attic insulation: 300mm recommended

Tue, Jun 17, 2014, 01:15

Yes it’s summer, and saving money on energy costs may not be to the fore of your mind.

However, a little preparation now to increase your home’s energy rating may help keep those ever-spiralling costs down when winter comes around again.

And, with the first domestic water bills set to issue from next January, and an average charge of about €240 expected per household, it might be time to change your water habits to prepare for the switch.

Attic insulation

It’s likely that most houses now have some form of attic insulation, given it’s one of the easiest ways to let heat escape from your house. But is it enough?

Typically, it was recommended that you insulate your attic with 150mm of product such as sheep’s wool or polystyrene. Now, however, if the depth of your attic insulation is less than 200mm, experts recommend you bring it up to 300mm.

The Sustainable Energy Authority of Ireland (SEAI) estimates a 540sq ft attic will cost you about €400 to insulate, but could save about €130 a year in heating costs, so it will pay for itself in about three years.

The ESB suggests the typical cost of attic insulation for a three- or four- bed semi-detached house is about €460.

And if you have a flat roof, insulating a 540sq ft roof will cost you about €1,000.

If you’re happy doing a bit of DIY yourself, you’ll find plenty of videos on YouTube giving you advice on how to do it. Just remember to shop around for your insulating material, as prices do vary.

There is a potential SEAI grant of up to €200 for attic insulation.

Wall insulation

If you wish to insulate your walls, the method you choose will likely depend on how your house is constructed – and the size of your budget.

Cavity wall insulation is the most cost-effective – you can expect to pay about €800 for a three- or four-bed semi-detached house – but is only suitable if you have cavity walls, which usually consists of two leafs of bricks or blocks with a space between them. Insulation is then pumped into the cavity through holes drilled in the surface.

If you’re not sure as to whether or not you have them, you can ask an insulation provider to check. A grant of €250 is available for this type of insulation.

If cavity insulation isn’t an option for you, you could consider dry-lining, whereby warm boards of insulation are attached to your wall and then plastered over. Building regulations recommend panels of about 75mm thick.

However, the SEAI suggests that if you have walls which currently have no insulation, then even the thinnest insulated panel, which would be 37.5mm thick, would result in the order of a 70 per cent reduction in heat loss through the walls.

Dry-lining a standard house will cost in the region of €7,000, with a grant available for €1,350. However, you will only qualify for this if you get all the external walls in the house done – getting walls insulated on the north-facing side of your house won’t suffice.

Finally, external insulation involves attaching insulating material to the outside of your house, and finishing with a weather-tight render.

While it effectively gives your a house a makeover, it is the most expensive option, at about €12,000-€14,000 for a standard house, and more for a larger property, but there is a grant available of €2,700. You will, however, have to finance the work up-front before you can apply for the grant, so it is a sizeable chunk of money to be parting with.


It’s estimated that about 60 per cent of your total energy usage comes from your heating – so while it makes sense to reduce the need for heating by improving your insulation, you should also improve the efficiency of your heating system.

According to Jim Curran, energy adviser with Electric Ireland, natural gas is “by far cheaper” than oil when it comes to heating your home, and it is also cheaper than electricity for heating water.

However as Curran notes, most homes in Ireland have just one heating zone, which means the radiators come on with heating water, as it’s all on one circuit. To avoid this, and bring down your costs, he recommends you put in two zones, so you can heat water separately from the heating.

This basic level of zoning will also ensure you will have a programmable temperature control through your thermostat. But Curran is quick to point out that reducing the temperature on your thermostat may not bring down your heating costs – a common belief.

“You cannot figure out what a degree on your thermostat is, they are typically very rough objects. So I don’t give that tip to people.”

A thermostat will cost less than €200 to install, while zoning your house will typically cost about €2,000 says Curran, with a grant available from the SEAI of €560 for this work. The work can involve pulling up carpets and laying new pipes, but a new level of smart control is coming in soon to the Irish market, which will be installed wirelessly. This will allow you to treat each room separately, which means that you could turn on the heating in your bedroom from the comfort of your couch using your phone. Curran estimates this will also cost about €2,000.

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