The planned increase in VAT from 17.5 to 20 per cent should have no impact on a range of energy saving products and services.

According to the Chartered Institute of Plumbing and Heating Engineering, there are a number of products and services that qualify for reduced or zero-rate VAT.

In January, these energy saving options should also escape the 2.5 percentage point increase in the headline rate of the tax.

Among the products that receive a chargeable rate of VAT at five per cent are energy saving materials for residential premises or charities.

Insulation can also be installed at a five per cent rate of VAT, HM Revenue & Customs advises.

Wood-fuelled boilers and renewable power facilities including wind and water turbines and solar panels can all be installed at the reduced rate.

The five per cent rate also applies to micro combined heat and power units, which can supply a property with its energy and heating needs together.