As an architecture student two of my main interests were environmental sustainability and architectural history.
However, the needs to conserve both energy and historic buildings are often in conflict. This is frequently demonstrated by the single-glazed window, which has been at the centre of a regulatory struggle between English Herritage and Building Control for decades.
The Bath Preservation Trust and the Centre for Sustainable Energy have collaborated to produce a survey about this balance. The value judgements are very difficult, but please do spend five minutes completing it.