Was wondering this, too - how is this offensive? Is the writer feeling that it's OK to heat the house so much that they can walk around in a T-shirt? I mean, great for you if your home is that well-insulated... even when I whack my radiators up to full volume, consuming tons of fossil fuel and spending a fortune, it's not warm enough for that in the winter.

However, the downside of the "just wear a jumper" piece of advice is that some homes are mouldy, and the mould spreads if you don't keep the place heated to a certain temperature. And pipes can freeze in winter. So it's not that easy.