Brian Mark on district infrastructure systems

We need to think much, much bigger if we are to make the sort of cuts in carbon emissions required of us at national and international scale.

One of the most obvious places to look for reductions is in our existing building stock, much of which is very old and thermally inefficient. There are already schemes that improve the fabric, but huge wins could be realised if we could decarbonise the heat supply too.

Conversely, the increasing thermal efficiency of newbuild projects means they will soon have to use costly technologies to generate low/zero-carbon electricity without heat or to purge heat into the atmosphere in order to generate enough electricity via CHP.

Why not balance these conflicting needs through linking properties to a community heating system? Add to this the possibilities of waste-fuelled CHP and we see even more potential for a holistic approach to sustainable infrastructure, including municipal solid waste and wastewater services.

It is these types of opportunity that make community infrastructure provision so important and potentially exciting. But community heating has a bad reputation in this country, mostly because of misguided attempts in the 1960s and 1970s. In Finland, however, 49% of the heat demand is served via communal systems and in Denmark it is more like 60%. Could it be that, just as we learned to forgive high-rise development for the mistakes of past decades, so we need to forgive district heating too?

Unfortunately, the financial case for district heating is often unattractive. While it may be the most cost-effective way of mitigating emissions in capital terms, the upfront investment required may mean it isn’t viable from a cashflow perspective. This and regional variations in land values, lack of competition among technology suppliers and a perceived innovation risk mean the future does not look good for community infrastructure in the UK.

Community heating has a bad reputation in Britain but just as we learned to forgive high-rise development for past mistakes, so we need to forgive district heating

Logically, however, this is the direction in which we should be going. I feel it is more a case of how rather than if. All the barriers discussed are surmountable, as other countries have shown. What we need now is a solution appropriate for the UK.

We should combine engineering with economics to encourage developers to contribute to infrastructure schemes that stretch beyond their site boundaries and engage with the existing building stock. This will improve efficiencies of scale and tap into more cost-effective carbon savings from the existing stock, and should also encourage greater integration of the individual developments that will form the towns and cities of the future.

To achieve this we will need a sensible policy framework that encourages design teams to respond to the problems and opportunities of a specific site. This will involve more than just engineers. Planners undoubtedly have a huge role in terms of strategic spatial planning and the new planning and climate change supplement to PPS1. Developers need to find new ways to engage with energy suppliers and new financing models will have to be explored.

Government, of course, has a crucial role through setting the over-arching policy framework and providing fiscal incentives. The recent consultation on the definition of zero carbon missed a huge opportunity to implement the fund mechanism proposed in the UK Green Building Council evidence base, which could have gone a long way to enabling community infrastructure. We will struggle to deliver on our targets without it.

This is not about favouring one solution over another, but more about giving developers as many options as possible. Community infrastructure works best in dense, urban environments, exactly the types of sites where many of the standalone renewables struggle.

The UK-GBC and Zero Carbon Hub task group on sustainable district infrastructure has been set up to tackle these problems and should provide some clear guidance for industry and government. Integrated developments designed with long-term operational efficiency in mind have to be the way to deliver sustainable development.