We are looking at purchasing a property and have come across two we like but they each have a different heating system and we’re unsure of how each of them could be upgraded, and the cost of doing so.
House 1 has electric radiators for heating, a number of which are quite old. In a Ber advisory report it was recommended that an air-to-water heat pump with the appropriate heating controls be installed. I wouldn’t have thought an air-to-water heat pump would be suitable for the house given the electric radiators. Could you confirm if that would be possible or what the possible upgrade for the space heating would typically be and an estimate of the cost?
House 2 has a conventional central heating system run on gas which I presume can be readily converted to an air-to-water heat pump. Could you please advise which house would be the easiest and cheapest option to upgrade from a heating perspective, assuming all else is equal?
Upgrading to modern renewable heating technology requires a whole building assessment. The efficiency of any heating system is directly related to the thermal performance of the building fabric.
Heat pump systems operate constantly at a low temperature. They require the building to be airtight with high levels of insulation. The information provided suggests that the buildings are old and unless there have been upgrades, solely upgrading to a heat pump will not work. The running costs of the heat pump system will be prohibitively expensive due to significant air leakage and resultant heat loss.
However, assuming the required insulation is provided and the buildings are airtight, I have taken both houses into consideration in my response.
House 1 uses electric radiators, many of which are old. The Ber advisory report suggests installing an air-to-water heat pump with appropriate heating controls. An air-to-water heat pump extracts heat from the outside air and transfers it to the water in your heating system. This recommendation indicates a significant shift from the current set-up.
Air-to-water heat pumps work best with water-based central heating systems (radiators or underfloor heating). Therefore, you would need to replace the electric radiators with a water-based system, which involves significant plumbing work. Adequate space for the heat pump unit and associated infrastructure is necessary. Just to note the costs quoted below are approximate and based on limited information. I would advise anyone contemplating projects like these to get a number of quotes from fully qualified and registered professionals.
Approximate cost for house 1 (excluding VAT and professional fees)
Installation of heat pump: €10,000 to €15,000; replacement of electric radiators: €1,000 to €1,500 per radiator, depending on the number and type (total cost could vary widely); additional plumbing and electrical work: €3,000 to €5,000. Total estimated cost: €15,000 to €30,000.
House 2 has a conventional gas central heating system. In principle, the existing water-based central heating system is already compatible with an air-to-water heat pump. This compatibility simplifies the upgrade process. However, the existing radiators and pipework will need to be assessed for compatibility with lower-temperature heating, as heat pumps generally produce lower-temperature heat compared with gas boilers.
Approximate cost for house 2 (excluding VAT and professional fees)
Installation of heat pump: €10,000 to €15,000; upgrading radiators (if needed): €1,000 to €1,500 per radiator, though radiators might be compatible; additional plumbing and electrical work: €2,000 to €4,000. Total estimated cost: €12,000 to €20,000.
Given the information provided, house 2 is more likely to be the easier and more cost-effective option to upgrade to an air-to-water heat pump. The compatibility of the existing water-based central heating system with the new technology minimises both disruption and expense.
House 1 requires a more extensive and expensive retrofit, making it less attractive from a heating upgrade perspective. Therefore, if all other factors are equal, house 2 is more likely to be the best choice for a smoother transition to a more energy-efficient heating system.
As advised, though, the buildings may well require much more significant and costly work to upgrade the insulation and provide air-tightness for a heat-pump system to work.
You should seek specialist technical advice for the proposed works so that a whole building assessment can be carried out. This will consider compliance with relevant standards including building regulations and will establish the extent of works. The Sustainable Energy Authority of Ireland has several grant schemes that you may be able to avail of and a register of technical advisers.
Damian King is a chartered building surveyor and a member of the Society of Chartered Surveyors Ireland
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