As if to counter this line of thought, the Zero Carbon Hub has just released it’s consultation on the next step of the Zero Carbon Definition – Allowable Solutions. Before we explore this in more detail, let’s take a step back and look at where we currently stand on the definition of Zero Carbon.
Current Definition of Zero Carbon
If you were to build a Zero Carbon house today, it would have to offset the carbon emissions associated with its entire energy consumption, through the use of onsite renewable technology. This calculation must include both Regulated and Un-regulated energy consumption. Regulated energy includes all energy produced by systems under the control of the Building Regulations – mainly, space heating, hot water, ventilation and lighting. Unregulated energy refers to energy consumption by household appliances, such as ovens, kettles, washing machines etc. and isn’t controlled by the Building Regulations. This current definition of Zero Carbon is not only very expensive to achieve, but is simply not possible on every development, especially high rise apartment blocks. As a result the definition of Zero Carbon is changing…
The proposed definition of Zero Carbon
Firstly, the proposed definition of Zero Carbon won’t include unregulated energy, reducing the amount of CO2 that will need to be offset (which strictly speaking means that a Zero Carbon Home won’t actually be Zero carbon…). Then to meet the Zero Carbon standard, developers will need to follow a hierarchy of requirements. This effectively means a developer needs high performance building fabric, measured by FEE, then needs to reduce the dwelling’s CO2 emissions to a certain figure, and finally use Allowable Solutions to offset the remaining CO2 emissions. It’s the proposal for Allowable Solutions that the Government is now consulting on.
Allowable Solutions – the Proposals
The consultation proposes 4 different ways in which a developer could offset a dwelling’s carbon emissions:
1. Offset carbon emissions using on site technology – e.g photovoltaic panels in a similar way to the current definition
2. Offset the Carbon emissions through “do it yourself” offsite work. This could include: - Upgrade the energy efficiency of offsite existing buildings, to offset on site CO2 emissions. - Directly invest or build offsite renewable energy or heating schemes. - Build in excess of current Building Regs standards, and “bank” the CO2 emission savings to offset further down the line.
3. Contract a third Party to deliver the required CO2 savings
4. Make a payment into a fund which then invests to deliver CO2 savings. The payment would depend on how much CO2 is produce by the development.
You’ll notice that only option 1 has a direct impact on the Energy Efficiency of the dwellings being built. The proposal also discusses the role of Local Authority asking the questions, should LA’s be responsible for delivering a Carbon Offset service and should this be left to the discretion of the LPA? Perhaps most importantly the proposals include a cap on the cost of achieving Zero Carbon, set at between £36 and £90 per tonne of CO2. This estimates the cost of Allowable Solutions for a detached house to be between £1274 and £3184. This cap allows developers to choose the most cost effective solution, and give clarity on build costs under the Zero Carbon Standard.
So what do you think? The consultation closes on the 15th October, but if you want to have your say check out the full consultation document: https://www.gov.uk/government/consultations/next-steps-to-zero-carbon-homes-allowable-solutions