Upgrading existing buildings is often more challenging than constructing new ones. It’s even more difficult when it comes to treating a post-war listed building located in a World Heritage site that is considered ‘hard-to-treat’.

The Canongate housing development, designed by Sir Basil Spence, is suffering several defects, from concrete decay to water ingress and ventilation issues. Improving the efficiency of this complex while preserving its architectural and historical significance is the ambitious objective of the Canongate housing energy efficiency & conservation project. A strategy based on the use of cutting-edge technology will help us understand the building’s behaviour and its defects. The findings will inform the measures currently being worked on by the design team, lead by John Gilbert Architects in order to solve the existing problems. Here are some of the technologies…

Thermal imaging

A thermal imaging survey being conducted using a thermographic camera. Courtesy of IRT surveys

Thermal imaging is generally the first type of survey to be carried out in energy efficiency projects, as it provides the designer with evidence about heat loss and ‘thermal bridges’. It can also help with other issues like water ingress, dampness on/condition of walls – renders in particular. To carry out this type of survey, a thermographic camera also called an infrared camera is required. The survey should take place when temperatures are low, heating is on and there is at least a difference of 10 degrees between internal and external temperatures.

Block 2 south elevation using a thermographic camera. Courtesy of IRT surveys

A drone was also used to survey the different roof types in order to assess the extent of heat losses (which are usually significant) and potential water ingress. Courtesy of IRT surveys

Energy consumption, temperature and relative humidity

A couple of monitoring devices have been installed in a sample of five flats and two business units to monitor energy consumption, temperature and relative humidity within the properties. These devices will gather data before the installation of the new measures, to understand current energy performance and habits. Data will also be collected during the post-installation period to assess the efficiency of the measures and the impact of advice delivered to the residents and property owners in the course of the project.

Devices recording temperature and humidity within the flats and commercial units

Graph representing temperature and humidity within a flat from a presentation by JGA

Devices recording energy consumptions on gas (left) and electricity (right) meters

Airtightness

Air permeability testing has been carried out in three flats to measure the airtightness of the building fabric. Airtightness could be defined as ‘the resistance of the building envelope to air infiltration with ventilators closed’, according to the English Building Regulations Part F (Ventilation) 2010. This test also helps to define areas of main infiltration and draughts.

Blower door unit installed in a property. Courtesy of Thermal Image UK

Fan controller for the blower door unit

A smoke test is used to assess possible draughts of an existing window

Indoor Environmental Quality

Indoor Environmental Quality monitoring has also been carried out by installing CO2 sensors in a couple of flats and in business units to assess CO2 concentration, which is an indicator of air quality.

CO2 sensor installed in a commercial unit

Graph representing CO2 emissions within a flat from a presentation by JGA

Wall U-value monitoring

U-value is the measure of heat transfer through specific building elements, for example a wall.  In other words, it indicates the level of performance of building elements as insulators.

Monitoring devices have been installed in order to calculate the in-situ U-value of the cavity wall and the precast windows surrounds. Courtesy of JGA

Keep an eye on our blog as we post more updates from the project.