By Jeremy Climas

10 August 2018

A couple of weeks ago, we had an open discussion about how a change to all electric vehicles might change what buildings are like. Automobiles are, for better or worse, a major driving force behind the structure of cities. Buildings are shaped - and their characteristics defined - by the behaviour of the cars around them.

One of the first things that many people notice about electric cars is that they are a lot quieter than combustion powered cars. To cover this aspect, one of our Acoustic Engineers, Josh Rodell, did some work looking at the potential noise differences - this is covered in a separate post.

This blog post focusses on the other aspects of building services design that might be affected. The most obvious aspect of MEP design to be affected by an increasing market share of electric cars is the need for more car charging points. Designing a car charging point or two in a car park is straightforward, but when car charging starts to become a larger part of the electrical demand, we’ll need to start designing for smart demand management; cars will need to be charged at off-peak times and perhaps even feed electricity back to the building at peak times. Intelligent management of the electrical storage in cars is going to become a major feature of our work in the medium term.

Fire is an interesting area to think about in relation to electric cars – current best understanding seems to be that they are less likely to catch fire than cars filled with combustible fuel; but the way they burn is quite different and they can re-ignite hours after apparently being put out. Tesla currently recommend that you’ll need about 100m³ of water to put out one of their cars. Battery technology research is still a big area and flammability is bound to be part of this. We might find that enclosed car parks in the future will need sprinklers and vast storage tanks.

Aside from noise, combustion also generates air pollutants (as it turns out, more than we all expected!) This means that, at the moment, we have to isolate the building ventilation from these sources of pollution and there’s been an increasing focus in recent years on filtration for NOx and locating building air intakes away from roads. These types of concerns will diminish as this major source of urban air pollution disappears.

Because of the pollution, you’d currently not consider bringing air into a building through the car park, but if all the cars are electric then an indoor car park becomes a potentially useful area of remote thermal mass. If it’s well ventilated at night and there’s tonnes and tonnes of cool concrete down there, using it as an air intake route in summer could be a fantastic source of free cooling.

Electric car development is moving fast and some big players are spending big money so the effects of electric cars are going to shift. MEP engineers will need to react quickly as the technology shifts.

Jeremy Climas is a Senior Engineer in our Cambridge office and can be contacted on 01223 240 155 or by email at j.climas@maxfordham.com.