I replaced my conservatory roof 2 years ago but went for a glass roof, which is energy efficient, self cleaning and opaque. I also had a cornice added inside which is insulated. Mine now looks like an orangery rather than a conservatory. It wasn't cheap but my conservatory is large and with everything cost £24,000 for the replacement roof which was more than the original conservatory. It also depend on several things, I didn't want to reduce the amount of light and it hasn't whereas a solid roof would have. My original conservatory was well built and strong enough to take the extra weight. Some of the quotes I got were sky high, double what I eventually paid. My conservatory was already well heated by radiators and a gas heater, it never suffered with being too cold but it was definitely too hot in summer and it isn't any more. Also when it rains now even heavily I can't hear it. I would have had it done much sooner had I realised how great it would be.