As switching to renewable technology is becoming more popular, Tim Pollard explains the preparations that property owners will need to take before having renewables installed, and how installers can help.

Renewable technologies are a wonderful thing. The huge reduction in energy costs they can bring, not to mention the money that can be earnt back from the Renewable Heat Incentive (RHI), will have some homeowners salivating with the dream of forking out less of their monthly pay check.

However, it is up to installers to help customers manage their expectations. Renewables work very differently to their conventional counterparts, so work often needs to be done on the property prior to installation.

The preparation needed to accommodate different renewable technologies may seem costly to the customer, but the financial positives of going green can balance the scales.

Heat pumps

Air source heat pumps are easier to install than ground source, but there are still a few things to consider before installation. The outdoor units aren’t particularly pretty to look at and most property owners won’t want them clashing with their prized petunias. It’s best to find a space out of the way to install an air source heat pump, such as down the side of the house or obscured by a garden structure, such as a shed. Specially designed surrounds are also available.

Ground source heat pumps require a large outside area for the laying of pipework, so are not recommended unless the property owner has a lot of land. The process is a long and messy one, so customers need to be prepared for a little upheaval.

Both air and ground source heat pumps run at a lower temperature than conventional heating systems, especially in the winter when the air and ground is much cooler, so it is essential that the property is insulated to the highest standard to avoid heat loss. Double glazing is essential and it is important that houses have adequate draft proofing.

Due to these lower flow rates, it is also recommended heat pumps are combined with underfloor heating, which may mean a little more disruption to the inside of the property.

Biomass boilers

Space can also be a bit of an issue with biomass boilers. The size of the boiler very much depends on the size of the property, but biomass also comes with the added necessity of finding somewhere to put a fuel store. The most popular biomass fuel is wood pellets, which need to be kept in a large container to ensure they are not damaged by the wind and rain.

Biomass boilers also produce wood smoke so it is important they are installed in a part of the property where the smoke will have space to dissipate.

Solar PV

With solar PV, installers need to take into account the size and strength of the roof and even the direction the house faces.

While houses built after the 1970s usually have ‘W’ framed trussed roofs, which are easily strong enough to support panels weighing about 20kg each, older houses often don’t have the same standard of trussing and will need reinforcing before the installation can be considered. It’s also worth the owner having their tiles inspected, as old and crumbling tiles will not be adequate to hold the panels.

South facing homes will get the most out of their solar panels but it is possible for west and east facing homes to have a good level of performance too. Installers should be conscious of the surrounding area, because the gradient of the roof and obscuring landmarks like tall trees can impact on performance.

Older properties

A lot of older properties provide more of a challenge for potential renewables installations. More work needs to be put into them than newer houses when it comes to heat loss. Double glazing and high quality insulation is essential to get a good performance from renewable technologies.


In a lot of cases it may be worth talking to the owner about installing a hybrid system.

This combines a renewable technology, such as an air source heat pump, with a traditional system like an oil or gas boiler. The renewable technology will take care of the heat load for most of the year – allowing the customer to benefit from lower energy bills and RHI tariffs – but, when the temperature drops, the fossil fuel boiler kicks in ensuring that the property is warm enough and taking the strain off the renewable system.

Forewarned is forearmed

There are plenty of reasons for installers to encourage their customers to make the change to a renewables system.

No two properties are alike, however, and it is good practise to speak to potential converts about the difficulties they could face along the green road, so they can have the most efficient and comfortable sustainable home possible.

Tim Pollard is Plumb and Parts Center’s head of sustainability