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Sustainability Policies in Bristol

Below is some feedback we received following pre-app advice with Bristol City Council.

BCS 13 Climate Change


All new development in Bristol should be designed with the future climate in mind through climate change mitigation &  adaptation techniques. Mitigation and adaptation measures must be integrated into the design.  Mitigation

Adaptation

Sufficient information has been provided on climate change adaptation measures.  The proposal conserve water through water efficiency measures and limit water use to 1051/p/d is noted and  supported. However further information should be provided to demonstrate how the development will meet  the following points;

The layout of the site should be designed to mitigate extreme temperatures brought about by climate  change. Orientation, form, massing and planting for shade should be carefully considered so that both  internal and external spaces are comfortable in hot weather.

The building design should mitigate extreme temperatures and risk of overheating brought about by  climate change. This should include good thermal mass, living walls and roofs, open able windows,  canopies, and external shading, and avoiding single aspect units. This is particularly important for rooms  on S and SW sides of the building. South facing elevations will receive more direct solar radiation around  midday when the sun is high in the sky. South-west facing elevations will receive solar gains when ambient  external temperature is at its highest, making the rooms on both South and South West elevations more  prone to overheating. The extent of glazing to the W facing rooms should be carefully considered as these  may receive unwanted solar gains from low level sun in the evenings. We'd recommend that overheating  risk analysis (e.g. following CIBSE TM59/TM52 guidance/other as appropriate) is carried out based on  dynamic thermal modelling in order to understand the implications of future projected temperatures (e.g.  in 2030 and 2050) on the development in order to mitigate the risks appropriately and ensure a  comfortable internal environment is provided without the need for energy consuming cooling equipment.

Further guidance produced by the NHBC foundation/zero carbon hub on understanding overheating and  design options for mitigation can be found here. Assessments using the steady state conditions SAP  compliance tool are not appropriate for the purpose of demonstrating compliance with the policy  requirement (i.e. for site layouts and approaches to design and construction which provide resilience to  climate change) because this tool does not factor in future climate impacts.  Development should minimise flooding through the use of sustainable drainage systems — please refer to  comments from flood risk manager.

Development should include blue & green infrastructure to both mitigate the urban heat island and  reduce surface water runoff. DM15 requires that new GI assets are designed to be multifunctional, and  expects the provision of additional and/or improved management of existing trees as part of new  development. Minimal green infrastructure is proposed. Further greening is required for example through  provision of a green/ green-blue roof with a deep substrate and minimal/no sedum blanket areas.  Development should avoid responses to future climate impacts leading to increases in energy use (e.g. air  conditioning systems).  20f5

BCS 14 Sustainable Energy

Calculation methodology

The calculation methodology (SAP12) is in line with Bristol policy, however the baseline energy calculation is not  policy compliant. This needs to include a policy compliant heating system, not electric heating as currently  included as this results in high baseline emissions compared to other policy compliant heating systems. The  calculations must be revised and a revised energy statement and table submitted.

Energy Efficiency

The energy efficiency measures proposed are acceptable. 

Heating Systems — Heat Hierarchy


The heating system proposed (electric heating) does not comply with the BCS14 heat hierarchy. The site is  within the heat priority area and nearby to an emerging heat network in the St Pauls area and is therefore  required to incorporate infrastructure to enable connection to forthcoming networks in the future. i.e a wet  communal heating system.  In accordance with the heat hierarchy, the preference is for this to be served by a renewable heating system  such as air source heat pumps. These could be located at roof level.  The applicant should provide a revised energy statement setting out how the BCS14 heat hierarchy will be  met through provision of a policy compliant heating source.

Renewable Energy


The proposal for PV is supported and this will meet the 20% reduction in C02 below residual emissions requirement.

BCS 15 Sustainable Construction

Waste & Recycling

The proposals set out in the sustainability statement do not set specific targets for construction waste  reduction/diversion from landfill. A Site Waste Management Plan should be conditioned to include these  targets.  The storage for bins and recycling should be provided in line with Bristol Waste's recycling planning guidance.  — see comments from Bristol Waste on the proposal.

Water

The water efficiency proposals are acceptable. Further consideration of the use of rainwater harvesting is  encouraged.
Materials 

The proposal for the use of A and A+ -rated BRE Guide materials in 80% of the major building elements as set  out in the sustainability statement is supported. 

Biodiversity

There do not appear to be proposals to enhance biodiversity or green infrastructure on site.  In addition to BS15 requirements about enhancing biodiversity, the Site Allocations and Development  Management Plan also links to biodiversity (DM15 and DM29).  Biodiversity enhancement options could include; sustainable drainage systems such as green roofs, brown  roofs, living walls, tree pits, swales, attenuation ponds to reduce surface run off and improve water quality,  wildlife areas, the inclusion of bird and bat boxes and the planting of fruit/ nut bearing trees. Green roofs  should be specified with deep substrate depths to support a greater variety of species, hold significantly more  rainfall, have a greater thermal mass and have greater evapotranspiration properties.  Revised proposals setting out proposals to enhance biodiversity should be submitted

Information & communications technology

The broadband statement submitted is for a different site. A revised assessment is required providing evidence  of the provision of high-speed broadband access and enabled provision of 'Next Generation' broadband.  Further guidance on demonstrating this policy requirement has been met can be found in the broadband  connectivity practice note March 2018

BCS 16 Flood Risk & Water Management

This policy requires Flood resilience and surface water management. Please see comments from the flood risk team.