Resilient London: confronting climate change
One of the magnificent Grade I listed crescents, which were originally designed by John Nash, has been rebuilt as the front elevation to a range of new residences. Behind the heritage facade is a new contemporary design. Radiating out from, and adjoining the main curved building are two existing buildings with 92 apartments that were originally built in the 1960s. These have been retrofitted and upgraded with a fabric first approach while the residents remained in occupation.
The transformation of these two buildings is truly remarkable, demonstrating how a failing building with spalling and cracking masonry can be saved and given a new lease of life for many decades to come. Of typical design and construction of the time, they were fitted with a large proportion of single glazed Crittall windows. Apartments were cold in the winter and overheated during the summer months.
A total retrofit overclad solution was conceived with thermal upgrade to the envelope comprising the roof, windows and walls. At eight storeys and 22 metres high, the design team needed to make very careful product decisions in terms of combustibility. Although prior to the recent new regulations, it was decided that products in line with the more rigorous standards would be selected.
The new warm jacket consists of a mineral wool, rendered wall insulation, selected for its high energy saving performance with aluminum faced timber windows to provide acoustic attenuation from the site conditions and traffic. Thermal bridging was checked at all key floor and window junctions, and fire and cavity barriers were installed.
The increased thermal performance has led to significantly reduced energy bills for residents, with studies of the savings in progress. More importantly is perhaps the much higher comfort levels with overheating considerably reduced and acoustics improved.
The structure of these two 1960s buildings was failing, the performance in terms of comfort for occupants was poor and energy bills high. If left, the buildings would continue to deteriorate giving an uncertain future for the residents. Given the significance of the connecting building, and the decision to demolish and rebuild this, the blocks also could have been a candidate for demolition. Instead, through respectful design, the buildings are saved and renewed, reducing landfill and saving carbon.
POE is in progress, data is currently being analysed and the results are looking very promising, it will encompass energy use, occupants reaction to the buildings in use and performance as resilient buildings for each season. The key issue was community involvement and that continues.