Draft Greater Cambridge Local Plan for consultation

We strongly support this policy.
Climate change poses an existential risk, so it’s vital that new buildings are Net Zero Carbon in operation.
To minimise carbon emissions in Construction, the policy should explicitly encourage and support the use of low carbon materials in construction, such as the use of timber (rather than steel and concrete), and rendered surfaces (rather than brick cladding)

We strongly support this policy.
Climate change poses an existential risk, so it’s vital that new buildings are Net Zero Carbon in operation.
To minimise carbon emissions in construction, the policy should explicitly encourage and support the use of low carbon materials, such as the use of timber (rather than steel and concrete), and rendered surfaces (rather than brick cladding)

Designing for a changing climate states that “development proposals should reflect the cooling hierarchy priority order”. In our view this is inadequate, because overheating is already a serious problem and climate change is going to significantly increase the risk. Solar Shading (for summer months) should be a top priority.
The report by the Committee on Climate change “Risks to health, wellbeing and productivity from overheating in buildings July 2022” points out that “around a fifth of homes in the UK are already overheating in summers today”, while the Environment Agency warns that we need to prepare for heatwaves temperatures to be 6.6C higher by 2100
The policy needs to be made significantly more detailed, with stronger requirements. It must learn from countries that already have the sort of climate we are likely to have here in future.
Careful consideration must be given to
• Glazing ratios on different orientations
• Solar shading (including building overhangs) on the more exposed elevations. Note that External shading is much more effective than internal shading for preventing overheating, and should be encouraged. If it is not initially provided, it should be made mandatory for external shading to be easily retrofitted at low cost, for example by providing secure mountings and easy access,
• White surfaces should be encouraged on exposed elevations to reduce heat gain, both within the building, and in the local area.
• Ventilation and thermal mass
Examples of good practise should be provided, learning from good practise in the UK and countries such as France, which already face the overheating risks that Climate change will bring here.
Guidance is particularly important for historic properties and conservation areas, building on best practise to balance heritage and habitability in a changing climate.
Evidence:
The French Connection. Report by Carbon Neutral Cambridge on French guidance to avoid overheating https://carbonneutralcambridge.org/wp-content/uploads/2026/01/22261final-French-connection-.pdf
Risks to health, wellbeing and productivity from overheating in buildings July 2022, Climate change committee https://www.theccc.org.uk/publication/risks-to-health-wellbeing-and-productivity-from-overheating-in-buildings/
BBSA guidance: How to handle overheating ...think solar shading first https://bbsa.org.uk/wp-content/uploads/2023/06/110645-BBSA-How-to-handle-Overheating-V3.pdf Research commissioned by the BBSA on a block of London flats, showed that the temperature (we feel) reached a scorching 47.5°C in rooms without shading. Rooms which had external blinds reached a maximum of just 28°C, a 41% reduction. Those with internal blinds closed peaked at 32°C
Addressing overheating risk in existing UK homes (Arup) https://www.theccc.org.uk/publication/addressing-overheating-risk-in-existing-uk-homes-arup/
Kensington and Chelsea Householder guidance for installing external shading on historic homes https://storymaps.arcgis.com/stories/a0f7a68066c5433781b3eb914597cadf

We support the policy, but it should be made stronger, in order to attempt to plan for a global temperature rise iof 4C by 2100 (as gvt policy advises). Encouraging White external surfaces (rather than brick) and slate will help reduce internal tempartures and heat island effects. See evidence submitted, first published on the Cambridge Carbon Footprint website

The longer the heatwave, the hotter houses become, even when taking exemplary passive measures to reduce overheating. As heatwaves will become hotter and longer in duration, it’s important that planning policy requires developers to design for this. See attached evidence for the results of research into the effectiveness of taking all reasonable passive measures to reduce overheating in an Edwardian terraced house in Cambridge, but also the steady rise in temperature day-by-day.

Please explicitly include encouraging "storage", because as grid decarbonisation approaches 100%, storage will be as important as generation. Similarly, please explicitly encourage proposals that will use the energy onsite

Suggested modifications
Paragraph 1: "The councils encourage proposals for renewable and low-carbon energy generation AND STORAGE, and associated infrastructure at all scales, including domestic schemes"

Paragraph 3: PROPOSALS THAT WILL USE THE ENERGY GENERATED ON SITE ARE ENCOURAGED, but where the energy generated is not used for on-site needs, provisions must be made for....."