In 2019, as part of the UK’s climate goals, the Chancellor of the Exchequer announced that from 2025, any new build properties will not include gas or oil boilers. This leads to the question of what is the most environmentally-friendly heating system that can be installed in your home? In this article we will run through how to most efficiently heat a property and some of the costs involved. The majority of this article focuses on the most ideal heating system for a new build. Some of these technologies are harder to retrofit and may not be appropriate for different housing types so at the end we will discuss alternative options should this be the case.
Providing the Heat
When it comes to actually creating the heat for your home, our recommendation would be a heat pump. Read our article for more explanation on what a heat pump is and click here for information on available grants.
We recommend ground source heat pumps over air source as they are more efficient and quieter. However, ground source heat pumps do require garden space and the land required will depend on the efficiency of your house’s insulation. The average surface area of land required for a horizontal ground source pump is approximately 2.5 times the square meterage of the house. For example, a 150 square meter house will require 375 square meters of land for the heat pump. The trenches for the ground source loops will be 1-2 meters deep.
Alternatively, if space is limited you could opt for a vertical ground source heat pump using a borehole. These can be more efficient as they are deeper in the ground and are not impacted by changing seasons. They do cause some disruption at the start due to the need for a drilling rig and are typically more expensive due to the need for specialist drilling equipment. You will need space for the drilling rig to enter the site, which can be tricky in built up areas, but the actual boreholes are only around 20cm wide. One borehole is usually sufficient for the average home, however if you need more they need to be placed 5-6 metres apart. It takes roughly 2 days to drill one borehole.
Both horizontal and vertical ground source heat pumps will require a plant room - a place for the unit part of the heat pump to go. These can vary in size from being small enough to fit in a cupboard under the stairs to the size of a fridge freezer.
If your home does not have any land for either a horizontal or vertical ground source pump, you can consider an air source heat pump. These are generally cheaper than the ground source but the returns will be lower as they are less efficient. They can also be quite noisy but are quick to install as they are about the size of a washing machine and can be put anywhere with a decent flow of fresh air.
Both ground-source and air-source heat pumps can be retrofitted and provide the most efficient source of heat with either traditional radiators or underfloor heating. If you are looking for the least disturbance in installation, we would suggest an air-source heat pump.
Electricity for the Heat Pump
In order to make your heat pump fully sustainable you need to use a renewable electricity source. You can either do this yourself using solar PV panels. These work best on an unshaded, south-facing roof with a 30 to 40 degrees pitch. It will require 10 to 20 square meters of roof space. However, due to the UK weather, often you will not produce enough energy to power your entire home day-and-night, which is why we strongly recommend combining it with a green energy tariff. If your home is not suitable for solar you can also switch to a renewables tariff. You can read about these here.
Heating the House
When building a new house, we recommend hooking the heat pump up to water-based underfloor heating, a much greener option than traditional radiators. Underfloor heating also works very well with heat pumps as it gives out heat at lower temperatures over longer periods of time. The heating system is not only greener but can boost the value of a property and will lead to lower running costs. However, underfloor heating can be difficult to retrofit.
For more explanation on underfloor heating read our article here.
Regulating the Temperature
We recommend installing smart heating which can automate your heating preferences and allow you greater control over your energy consumption and spend. Most offer the ability to control heating room-by-room, avoiding heating spaces unnecessarily and can often be controlled remotely from your phone, meaning you don’t need to panic if you accidently leave the heating on! Read our article on smart heating here.
Smart heating can be easily retrofitted.
Keeping the Heat in
In order to increase the efficiency of all these measures you need to ensure thorough insulation. Insulation will reap great rewards in exchange for the upfront cost and will often payback in a short amount of time, even if retrofitted.
Draft proofing and lagging are two types of insulation which can be easily done yourself. Wall, roof and floor insulation will require professional help, making it more expensive, but it will still deliver comparatively greater energy savings and carbon footprint reduction.
If for some reason you choose not to install a heat pump, maybe due to cost or you live in a flat where a heat pump would not be appropriate, we would suggest you opt for electric heating. You can read more about this here.
Electric heating is more efficient than gas boilers as typically 100% of the electrical energy used is converted into heat and there are no combustion losses and piping losses. However, it is not as efficient as a heat pump, which can achieve more than 300% efficiency whether it is connected to radiators or underfloor heating.
Please also bear in mind that whilst with electric heating you will see efficiency gains over gas, this will not help your carbon footprint if you do not get your supply from a renewable source, whether that be your own solar PV or a renewable energy tariff.
If there was enough renewable energy to power the whole country, opting for these over a heat pump would not create a greater carbon footprint. However, until there is enough renewable energy for all homes in the UK it is better to choose heat pumps which can have 350% efficiency over electric heaters which have 100%.