Buildings must meet strict energy efficiency criteria from 1 April to qualify for the full level of feed-in tariff. When the government announced the change earlier this month it was not clear whether or not the solar PV installation would count towards the Energy Performance Certificate level D or not.

Now the Department for Energy and Climate Change (DECC) has confirmed that it will. First in a tweet to YouGen it said: "@YouGenUK @linniR policy is that building needs to be at level D, we don’t specify how this is reached – see EPC info bit.ly/xlISv9".

Yesterday DECC has enlarged on the 140 characters allowed by Twitter, saying to Business Green: "People would need to have the EPC certificate before they apply for support under the feed-in tariff, but they could decide installing solar panels forms part of the property reaching Band D".

The spokeswoman added that different properties may require varying amounts of energy-efficiency measures to reach Band D. While some will require insulation or a new boiler, others may only require solar PV to gain a Band D certificate.

Generators must submit an EPC as part of their application to their FIT supplier to receive the feed-in tariff. In buildings that currently do not have an EPC, it is possible to get a DEA (domestic energy advisor) to advise you on what, if any, additional measures you would need to reach the required level.

A number of energy efficiency measures, such as loft and cavity wall insulation and draught proofing measures will have quick returns on investment and instant improvements in comfort. There are lots of really good deals to be had on insulation in 2012, and it is unlikely to ever be as cheap again once the Green Deal is launched in October.

If you have a question about anything in the above blog, please ask it in the comments section below.