Agenda item

Proposal:

1. Pre-application proposals for Phase 5 - Reserved Matters seeking approval of appearance, landscaping, layout, scale and access in relation to Buildings F01, G01, G02, J01 and J02.

2. Use of Sustainabrick building façade facing material on Phases 4 and 5.

Valerie Okeiyi, Principal Planning Officer, introduced the report for pre-application proposals for Phase 5 - Reserved Matters seeking approval of appearance, landscaping, layout, scale and access in relation to Buildings F01, G01, G02, J01 and J02. Use of Sustainabrick building façade facing material on Phases 4 and 5. 

The following was noted in response to questions from the committee:  

• The Sustainabrick system had a design life of 60 years, equivalent to that of a conventional wall. It met all relevant building regulations. The foundations did not need to be as large or as deep, resulting in reduced concrete use and improved sustainability. It was also more cost effective. 

• Regarding affordable housing provision, this had been established within the wider masterplan several years earlier. The pre-applicant advised that they had delivered the level of affordable housing they were obligated to provide, and in some cases  more than required. Recent economic challenges had not adversely affected the scheme; the developers had continued to progress the project and had found ways to withstand current market pressures while still delivering the affordable housing commitments made years ago. This was considered a positive outcome. 

• In terms of height, the pre-applicant team stated  that at their Kidbrooke development they were delivering a 22?storey building.The tallest building in Phase Five would not use Sustainabrick but instead an aluminium system developed, following  review by QRP. They were also exploring the delivery of 26?storey high buildings in Greenwich. 

• On the issue of adhesion, it was acknowledged by the pre-applicant that there had been failures in the past. The team had reviewed various slip systems, including mechanically fixed systems and adhesive?based systems, the latter of which had historically experienced issues. They had spent three and a half years undertaking research and development with Monolith, the manufacturer. The proposed system addressed potential failure by embedding the slips in a mesh, which would then be adhered to a waterproof Sto render. Behind this would sit approximately 20mm of additional waterproof render, followed by a further waterproof sheet, insulation of varying thicknesses, and finally the SFS (structural façade system). 

• From a sustainability perspective Officers advised that brick production methods significantly influenced embodied carbon. Alternative drying methods could reduce this impact, and using only part of a conventional brick also lowered embodied carbon. Reducing façade weight further decreased the embodied carbon required for the superstructure. These principles were supported in general. 

• However, questions remained regarding the sourcing of raw materials, including transport distances, which formed part of the broader sustainability assessment. Mortar use was also raised as an issue: traditional lime mortars allowed bricks to be dismantled and reused, whereas conventional cement mortars did not. It was noted that the proposed system did not appear to allow for deconstruction in this way. 

• The pre-applicant reported having four projects across their portfolio at various stages of Gateway 2 approval. The scheme closest to receiving consent, which also proposed this product, was at Royal Arsenal Riverside. The regulator’s concerns had not related specifically to the product but to structural engineering matters. Determination times were inconsistent, and no applications had yet been processed within the statutory 12?week period. 

• QRP responses, and the applicant’s response to their comments, would be included within the committee report on the Phase 5 application, once ready for consideration by PSC Members. 

• The pre-applicant advised that exploring alternative construction systems helped maintain the overall viability of the scheme. This avoided the need to reduce build quality or affordable housing provision. Although the system was not substantially cheaper than conventional brickwork, it contributed to making the wider scheme financially deliverable. Pricing would still need to reflect market conditions, but the priority remained delivering the committed levels of affordable housing. 

• The pre-applicant stated that the 60?year design life referred to the specification of individual building components, rather than the lifespan of the building itself. While components were rated for 60 years in line with manufacturer and warranty requirements, the building was expected to last significantly longer—potentially hundreds of years.