Cut your utility bills with home retrofits

The SEAI advises: “A building contractor or architect will be able to tell you what type of wall your home has. Your Contractor will also be able to advise you on the type of ventilation required.” 

Ensuring adequate ventilation is a key element in these serious insulation projects where we are tightening the house up against air-exchanges.

First is the common practise of cavity fill, a highly cost-effective way to deal with that gap between the internal and external leaf of block, allowing damp and cold to cross over into the house.

Injected from outside the house and with minimum disruption, grey pumped polystyrene beads can be used to add a thermally powerful layer. If you are not sure if you have cavity fill, try a little outdoor sleuthing for signature drill holes. The area around the cable or meter boxes attached to the outside of the house may also show signs of a former foam install.

Cavity fill will not stop damp, but it can regulate it. It is not a cure for rising damp, and if you find these kinds of problems in your travels get advice from your builder or engineer. Grant aid, €700 to €1,700 depending on house type. Apply using the online SEAI Wizard.

Dry lining is a familiar improvement in Irish homes with both cavity, timber-frame and solid walls. It does have its detractors for heritage builds with “breathing” stone and lime-plaster walls.

Affordable with generous grant aid of €1,500 to €4,500 (around 30% of the costs), the SEAI advises: “Internal wall insulation involves attaching an insulation board to the walls and covering it with a vapour barrier layer and plasterboard. You will lose room space and will have to take out and refit kitchens, cabinets and appliances.” 

The SEAI continues with this technical advice: “Installation of wall insulation requires a level of competency, experience and the use of specialist equipment, meaning installation is not a DIY job for most people nor will the scheme provide support to people completing DIY installations.” 

External wall insulation (EWI) is a complex job but popular with deep-retrofit projects where it can bring the “U” values of vintage external walls to the level of A3 rated new builds. Disruptive to outdoor elements, and generally embedded in a whole house renovation, EWI will make a world of difference to a freezing, sieve of a house.

Once finished with the additional building works and crucially, a change up to high performance windows and doors, the project can lift the home’s whole visual appeal. Whole house EWI must achieve a B2 to comply with Part L of the building regulations.

SEAI grant aid is graded from €3,000 for an apartment to €8,000 for a detached house for EWI. With the One-Stop-Shop retrofit through the SEAI, €1,500 to €4,000 is available towards new windows, and €800 per external door (2 max).

Photovoltaic Installation (PV): Significant capital outlay, steady but slow return.  SEAI grant aided but this no longer covers a battery 

Solar photovoltaic (PV) has received a bounce with the stratospheric increase in electricity prices. If you have the roof-space it’s well worth consideration as a remarkable, renewable source of energy.

PV has a high capital outlay that has increased in recent years (battery prices remain high). However, researchers at MaREI, the SFI Research Centre for Energy, Climate and Marine in University College Cork (UCC), found a quarter of all the electricity needed by Irish households could be produced by putting solar panels on domestic rooftops. Funded by the Irish Solar Energy Association (ISEA), the study found about 1 million homes in the country were suitable.

An appropriate PV system can be designed for many homes with a choice of financing from grant-aid and savings, to green-loan mechanisms with a low interest rate, and moderate payments over three to five years from your credit union or bank. With bigger retrofit projects, the cost can potentially be rolled into the mortgage and One-Stop-Shop device. With the rise in kWh unit prices from suppliers, the payback period for PV has contracted, often to 7 to 10 years for a moderately sized array of 3kWp to 4kWp of panels.

Emerging feed-it-tariff payments through the Microgeneration Support Scheme (MSS) offer 14c to as much as 21c per kWh from suppliers, exported in surplus power back to the Grid (a bite out of that dreaded Standing Charge).

The ISEA adds: “Payments are backdated to 15 February 2022 or when the customer becomes eligible, whichever is the later. The key requirement for eligibility is that the installer registers the system with ESB Networks.” Storage batteries and water-diverters will increase your spend, but will add to the overall 24-hour versatility of your PV system. Gathering free electricity even on overcast days, PV Solar can make a modest contribution to running your electrical heating (HP and IR) and the range of any home charged EV car.

PV grant aid is graded by kWp and capped at €2,400 for 4kWp of panels on the roof.

The ISEA advises: “You can participate in the MSS if your home was built prior to 2021, regardless of the property’s BER. This makes eligibility highly likely for most Irish homeowners.” 

In terms of the capital investment, the ISEA continues: “We recommend shopping around and securing quotations from a number of installers. Other options worth considering may include reducing the size of the system, securing green finance, or there are providers offering solar equipment rental.” 

The full on-the-ground survey for your PV project, is a vital moment as you are relying on the skill of your supplier to design and detail your system. You should have an idea of your annual electricity usage in hand – refer to your last six, bi-monthly bills.

Planning permission is no longer required for domestic PV Solar systems but there are design and positioning considerations around the installation that are obligatory conditions to secure SEAI grant aid. Good old Solar Thermal panels, also sited on the roof or framed up on the ground, offer a less costly alternative if you are simply after free hot water: €1,200 grant aid.

Warming to heat pumps

The SEAI retrofit grant system is ultimately focused on getting as many older homes as possible in Ireland what is termed “heat-pump-ready” (HP) and diminishing the use of unsustainable, polluting fossil fuels for domestic heating.

For a house in the G – C cache of Baltic BERs, this is likely to be a costly business, but it will bring your home to the thermal comfort levels of a relatively new house. If you home is insulated to the right level and has low heat loss (HLI) with managed ventilation, it may be ready for a whole, new sustainable heating system.

HPs are electrically powered devices that use a compressor and coolant similar to that used in a refrigerator. They gather renewable solar gain stored in the earth, air or water (termed the collector) and using a vapour compression cycle transform it into energy we can use to heat our indoor air and water.

Heat is emitted around the house using forced air, conventional under-floor-heating (UFH) or suitable water fed radiators. Your gas and oil bills in a hybrid system incorporating a HP, will be reduced (or eliminated) but your electricity bill will go up. Currently that kWh number matters and must be tamed with the right energy package. 

Air source heat pumps are the most familiar HP in a retrofit situation (ASHP) and at point-of-use all HPs have zero carbon emissions, utilising only a trace of electricity to function.

An ASHP sits in a box on an outside wall, easily set beside or behind the house. With an internal fan, they do produce noise while running of 45-60dB. Sited at least a metre from a bedroom window, this should not be a nuisance for you or a close neighbour (check the rating on the unit’s certification before you buy).

Compared to even high efficiencies of 90% plus in conventional oil and gas boilers — appropriately installed, HP systems regularly produce 200-300% in terms of energy efficiency. In the best scenario for every unit (kWh) of electricity used, 3-4 units of thermal energy (kWh) should be returned. Termed the Seasonal Coefficient of Performance or SCOP, this can fall to 2-2.5 in winter with an ASHP.

The most impressive SCOPs are taken from new builds or superb deep retrofits with vertical geothermal bores, extensive UFH and superb insulations. Put into inappropriate settings, where the fabric of the house is not ready for the HP, they can be very costly to run.

For this reason, qualifying for a Heat Pump Grant of €4,500 (apartment) or €6,500 (for a house), is not as simple as having a B2 BER. A Technical Assessment (charged for) is carried out to ensure the insulation and heat loss levels (HLI) of the home will make the unit truly efficient. Other improvements may need to be carried out to prepare the house —some with, and others unsupported by grant aid.

The Technical Advisor will provide a crucial road map towards making your home HP-ready, based on a highly specific heat loss indicator (HLI). This is 2.0 Watts/Kelvin/m2 or in rare cases 2.3 Watts/Kelvin/m2.

There is grant aid for the Technical Assessment — this is given only after recommended fabric upgrades take place. The assessor will be able to determine if elements of your existing system will suit HP, including the radiators, which must be over-sized to suit lower flow rates and temperatures. HPs are less reactive than fossil fuel systems, and typically run in the area of 35 - 45°C over much longer periods.

In some cases, the cost of the work required as determined by the Technical Advisor will make a HP impossible in one financial jump. Independent grant aided insulation and improvement projects over a longer period might suit a homeowner better than a deep-retrofit in a single flash of high spending.

Moving from a traditional oil boiler, there’s the chance to upgrade to a condenser-boiler with high efficiencies that is bio-fuel ready (to use hydrogenated vegetable oil/HVO or bio-gas). Whatever heating system you settle on, the insulation/air-tightness and ventilation of the house remains crucial to its overall efficiency.

You won’t get a grant if you are using a HP for water alone or using a hybrid system to heat the house. “Grant funded systems must be designed to meet 100% of the dwelling space heating demand and at least 80% of the hot water demand,” says the SEAI.

ASHP are a logical retrofit for many homes and the least expensive HP prospect, as they don’t demand an array of buried pipes as geothermal does. The end-goal for most serious deep-retrofit projects within the One-Stop-Shop process or using individual grants is a sustainable heat source. 

Juggling the capital to reach a B2 or better can be challenging, and even the BER won’t tell the whole story. Don’t go it alone. Unless you have specialist experience, investigate through the One-Stop-Shop route or with an SEAI Technical Assessment, following up with quotes from suppliers and installers when, and only when, the house is deemed heat-pump-ready.

To find out more about SEAI grant aid, explore the Grants section and their new Energy Hub pages of explanatory video content at www.seai.ie.