Regent’s Crescent utilises a range of measures to achieve impressive carbon savings
One of the magnificent Grade I listed Regency crescent façades which were originally designed by John Nash has been rebuilt and reimagined as contemporary apartments and garden villas, reverting the site back to its original residential use. Our approach from the outset was to produce a thermally efficient and technically sound building with a potential to take us forward in our shared vision of a Net Zero London.
The building is Grade I listed and unusually combines a heritage façade in a contemporary building with existing structures, garden villas and a buried Scheduled Monument (an ice-house was discovered in the grounds). From the outset sustainability and a low carbon footprint were key considerations. Included in the scheme are on-site energy generation, green walls and roofs and a number of other measures but key to the approach was thermal efficiency, good airtightness, good thermal mass and limited solar gains in the building fabric as this leads to a reduction in operational energy use and carbon. As a result, the scheme achieves a 35% carbon reduction above what is required for operational use.
Photo voltaic panels are incorporated in the cladding system
Key measures used for this project are:
The heritage façade is reconstructed with pre-soaked, unused bricks for movement reduction, providing extra thermal mass, no material was suitable for recycling on site.
In the heritage façade traditional methods such as lime mortar, lime stucco render with Keim breathable paint applied ensure good hydrothermal conditions are met to avoid interstitial condensation and mould growth.
The thermally efficient fabric to the new build element has low ‘Space Heat Demand’ and features good thermal mass by the use of masonry, concrete and enhanced insulation standards.
Reduced thermal bridging in the building fabric to the new build element limits thermal bypass in the terraces, balconies, cladding and roof thus improving the surface temperature factors and boost to MVHR (Mechanical Ventilation with Heat Recovery).
The two existing 1960s apartment blocks were thermally overclad with mineral insulation and modern replacement windows and all verified with thermography.
For on-site energy generation there are 180 sqm of vertically mounted photo voltaic panels built into the south facing upper window walling as an integrated cladding system.
The development also has green walls and roof, water attenuation, solar control, good airtightness and limited solar gains by installing shading and solar control glass and CHP (Combined Heat and Power), site energy network.
During construction, the use of measures such as prefabricated bathroom pods provided low site logistical impact as well as an energy efficient factory process and efficient use of materials.
Whilst our achievement with this project is an impressive and major step forward for a building of this type, we know much more is possible in the future. As we continue to develop techniques and apply knowledge, we look forward to achieving greater reductions to contribute to a Net Zero London for 2030. A post occupancy evaluation of Regent’s Crescent will be made next year.
We believe that as architects, we need to be firmly aware and take responsibility for our impact on the environment. PDP London is signatory of the Architect Declare declaration and the AJ RetroFirst campaign and apply their principles through conscious planning, design and construction (fabric first) and through careful thinking of the maintenance and operation of our buildings. We also embrace restoring nature to promoting biodiversity, optimising the health and wellbeing of people and creating long-term value for society with an improving quality of life.