I was very interested in the measures required to upgrade a 100-year-old house in respect of thermal efficiency (7 July, page 44).

This has made me reflect on what measures may be required to “futureproof” the increasing number of lightweight off-site houses that are being constructed. There is compelling evidence that high thermal mass in conjunction with other passive methods are essential in making our homes last and avoiding the need to install mechanical cooling. The benefits of thermal mass are at last mentioned in the latest Part L approved documents as part of a strategy to combat higher internal temperatures. Clearly it will be considerably harder, if not impossible, to retrospectively upgrade homes to incorporate sufficient thermal mass.

I wonder what future generations may think of us, given we have the knowledge and the materials to provide long-lasting homes, but choose to ignore them.

Chris Jarvis, building surveyor, Sussex