2 expert articles on conservation areas for London period sash windows, from heritage specialists with 15 years' experience.

• Secondary Glazing vs. Double Glazing for Listed Buildings: Which Passes Conservation? — Improving the thermal performance of a listed building requires more than choosing the most efficient glass available. The proposed work must also…
• Grade II Listed Window Draught Proofing: What Conservation Officers Don't Want You to Know — Owning a Grade II listed property does not mean you must accept cold rooms, rattling sashes and high heating bills. It means that improvements need to…