It's getting harder now to find companies who are still doing it free for people NOT on benefits or over 70, but do a google search insulation grants in your area, because some do still have funding. Most have freephone numbers.

If you have narrow cavities (30-45mm) or solid walls, you may well get those done free now. Again, contact an insulation contractor and ask them to do a survey, which will be free of charge.

The government-backed 'Green Deal' scheme has now started, and that also covers other things like Photovoltaic solar panels, replacement boilers etc, but it's up to you to decide whether they're likely to be worth it or not...especially if you're not going to be in that house after a few years.

I'm just doing my 'Green Deal Assessor' course at the moment.