Greater Cambridge Looks at Growth Options- Dense Development Produces 1/3rd CO2 Emissions

Important document yesterday from Greater Cambridge

If ambitious zero carbon policies are brought in, almost no CO2 would be produced by the building’s energy use itself and less than 1 tonne of CO2 per home would be generated by the carbon needed to build the home in the first place (this is calculated by spreading the upfront carbon emissions of the construction over the anticipated lifespan of the building). The rest of the carbon emissions are created by the travel patterns of the residents, which is why new homes in villages are likely to create over three times as much carbon as new homes in denser urban areas. 

Water supply analysis shows that the minimum required level of growth could be plausibly achieved through adjustments to current water resource management plans, such as greater water efficiency, reducing leakages and shifting to more sustainable water sources. Medium or high growth levels would need new regional scale infrastructure, such as reservoirs and transfer schemes, and this will inform plans currently being developed by the water industry.  Under normal means of provision, these will take time to implement, and this could be a ‘deal breaker’ that means high growth levels cannot be achieved within the period of the new Plan. 

From a water management perspective, the best place to build new homes would be in new settlements, or to build large developments on the edge of Cambridge. This is because they can be designed from the outset for efficient and integrated water management, rather than having to ‘bolt on’ to existing infrastructure in the city or existing villages where there may be existing flood risk, wastewater and water quality constraints 

The full document lists a number of strategic spatial options – well done 3/4 of plans don’t. Though it should have made clear that they arnt mutuallt exclusive. The option numbering and naming system is confusing -two different systems showing a lack of editing, but they broadly make sense.

Options include edge of Cambridge, an option focused on the A428 corridor and another new settlement/corridor based option based on employment growth south of Cambridge.

What I take issue with is the entirely arbitrary size thresholds for new Settlements – based on the airfield sized settlements of the past not research on what a sustainable size reducing carbon emissions through maximising cycling and bus use and optiising infrstructure use would be. That would be units of around 9-10,000 (secondary school units)

I must stress also that the A428 will never be a public transport corridor. Any PT route alongside the A428 will carry a tiny percentage of modal split and settlements alongside the A428 corridor will always be car based. The evidence points towards rail and busway growth that can access Cambridge and in particular its new Life Science cluster. Which is why so many were dismayed at the specular sub optimality of the southern route for the East West Rail. That wont last it was a bad decision that will fall apart ay inquiry given testing of route options (never done) combined with development options an their carbon output.

I have even drawn up such a plan based on a new settlement around Bassingbourn, and have subsequently found AECOM and David Lock have independently produced similar plans. This Hertfordshore/Beds Border option could meet shared needs.

Well done though Greater Cambridge – we just now need map based options for study – ideally Masterplan led.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s