The Code for Sustainable Homes and redefining zero carbon are well intentioned but, says Pooran Desai, we’re going to need a far more radical rethink if targets are to be met

We will get through this downturn. Sooner or later. But what really matters is that we come out the other side ready to create a sustainable, low-carbon future. We have tied ourselves in knots with the Code for Sustainable Homes and zero carbon. Now is the time to cut through the green tape and create standards and processes that will enable us to deliver zero carbon both effectively and cost-effectively.

The code isn’t all bad. Up to level four, the standards are basically sound. However, levels five and six are of dubious environmental value and have inherent problems. The industry accepts that demanding “net zero-carbon” on-site generation is not helpful. On higher density sites where it’s impossible to collect enough rainwater to flush toilets, the higher code levels force developers to use on-site grey water treatment, which is often energy and chemical-intensive. The solutions needed to deliver levels five and six are expensive in capital terms and have high maintenance costs and many homes built to level five or six will actually be less eco-friendly than level four.

Then there is the unnecessarily vexed question of zero carbon. The thinking underpinning recommendations from the UK Green Building Council’s (UK-GBC) Zero Carbon Taskforce and the recent consultation from the communities department will not result in a workable solution, as they not grounded in practical application. New criteria include “allowable solutions”, where some carbon reductions are met by measures including providing district heating to nearby existing buildings. The complexities of demonstrating that developments meet these criteria will add to bureaucracy, cost and delay. And we already have a painfully tangled planning system.

Our experience as developers now shows we are often spending more money, up to four times as much, on sustainability reports for planning authorities, the Environment Agency and BRE as as we are on renewable energy technologies.

An all-round approach

So, what is the solution? Our starting point must be creating sustainable lifestyles, in which green buildings are one component. Taking this more holistic perspective, we see that increasing the space heating performance of homes from code level four to five will save about 750kWh of energy per person per year which, if replacing gas, would amount to just 1% of a person’s carbon footprint and would save only relatively small amounts on energy bills.

We are spending up to four times as much money on sustainability reports for planning authorities, BRE and the environment agency as we are on renewable energy technologies

However, reducing car dependence by building communities that are walkable and cyclable reduces costs and the embodied carbon of construction of parking and road infrastructure. Each car avoided saves a household over £2,000 a year and perhaps 10% of a person’s carbon footprint (as well as helping to tackle our epidemic of obesity and diabetes). This understanding of overall costs and benefits must inform the standards we set. When the industry can deliver code level four space heating performance, for instance, (which it can’t at the moment), we can then raise minimum standards to get that last little bit of energy saving from the building fabric. But let us face facts – the savings will be small.

The real solution to zero carbon lies in a recognition that electricity is best considered as a pooled resource and that creating a low-carbon electricity supply should be led by national energy policy rather than trying too hard to turn buildings, directly or indirectly, into power generators. We need a green grid which we must accelerate through increasing incentives through renewables obligation certificates (ROCs) – money paid for generating energy using renewables and feed-in tariffs (plus heat ROCs).

Let a natural, economic balance of on- and off-site solutions emerge. “Allowable solutions” are an unnecessary complication. We already have grant schemes like Warm Front which can be boosted through communal central government funds. Let’s use those, rather than introduce another initiative and a fresh burden on new homes, pushing many sites deeper into non-viability.

Using this approach, truly sustainable developments can be built. Since 2003, BioRegional has been using zero carbon to refer to buildings run on a combination of on- and off-site renewables using fossil fuels only as back-up. The One Brighton housing scheme is being built by BioRegional Quintain in joint venture with Crest Nicholson on that basis. The 172 apartments are being built within conventional cost parameters to this zero-carbon definition, with a biomass boiler, gas back-up heating, bulk purchase of guaranteed green electricity and support for off-site, large-scale wind turbines.

It is through real-life experience and learning that we must take our lead. Let us by all means move to code levels five, six and zero carbon, but with clear, workable, environmentally beneficial solutions.