Improving Thermal Performance of Historic Building Windows

Introduction

Improving the thermal performance of building envelopes is crucial for enhancing energy efficiency. Windows, especially single-glazed ones, are often the weakest thermal components in buildings. This challenge is particularly pronounced in historic buildings, where outright replacement of windows is usually inappropriate for conservation reasons. However, various measures can be taken to improve the thermal performance of such windows, as demonstrated in Historic Scotland Technical Papers 1 and 9. These include draught-proofing, using curtains and shutters, fitting secondary glazing, and replacing single-glazing with slim-profile double-glazing. The latter offers a significant thermal improvement over single-glazing while being suitable for installation in existing window sashes, preserving the original joinery, which is essential for conservation.

Overview

Historical Context and Initial Findings