"Hard to Treat" (Home Insulation Scheme)
In the UK there are over 10 million homes where
the most cost effective energy efficiency measures (e.g. cavity and
loft insulation) are unsuitable. These include: older homes with
solid walls; homes with no loft space; homes without a connection
to a low cost fuel such as oil or gas; and homes where, for
technical or practical reasons, simpler energy efficiency measures
cannot be fitted.
Your home may be one of these.