Meeting London's Zero Carbon commitment
The government may have dropped its national zero carbon commitments but from 1 October all major new-build residential developments in London will need to be ‘zero carbon'.
Report from – Beverley Rosso, Stroma Tech
With the Brexit vote almost three months behind us, figures from the Office of National Statistics are beginning to show the first signs of its impact upon our economy and employment levels, albeit it is too soon to draw conclusions. Its effect upon our energy performance policy is certainly yet to be understood as we await confirmation of how targets associated with the European Performance of Building Directive (EPBD) will be affected.
However, outside the bounds of the EPBD is The Climate Change Act (2008) which defines the Secretary of State’s obligation to ensure that net UK carbon account for the year 2050 is at least 80% lower than the 1990 baseline. Although uncertainty still surrounds the future of energy policies, these targeted Zero Carbon incentives drive the UK towards an improved standard of energy efficiency.
Zero Carbon - balancing value and cost
In pursuit of reducing our built environment CO2 emissions, there have been a number of developments to Building Regulation Approved Document Part L and various auditing and incentivised savings schemes have been introduced over the past decade. These incremental changes to targeted CO2 savings of new-build projects have brought us ever closer towards achieving a Zero Carbon standard and contributed towards the 2050 goal.
To balance the urgent need for more housing while raising performance standards for new buildings, specialist research has been carried out to define the optimal balance between adding value and inevitable costs. Although costs have fallen due to an increased demand for renewable energy technology and a drive in product innovation, case studies show that a more cost-effective and practicable approach to reducing CO2 emissions may lay outside of the site boundary.
London’s commitment to the zero carbon standard
Across London, major building developments have had to comply with relatively difficult CO2 targets beyond those of the Building Regulations since 2010. From 1 October 2016, major new-build residential developments will need to achieve ‘zero carbon’, with non-residential to follow suit in 2019. Between the 1 October and the introduction of Zero Carbon, major non-residential developments will still be required to achieve a 35% reduction in CO2 emissions. This has been unaffected by the recent postponement of the national standard and the Written Ministerial Statement limiting performance requirements by local authorities. The London Mayor’s Supplementary Planning Guidance (SPG) defines the required zero carbon standard to achieving at least a 35% reduction in CO2 emissions below the 2013 Part L compliant baseline. Residual regulated CO2 emissions to 100% are to then be off-set via a cash-in-lieu payment to the relevant borough in order for them to secure delivery of CO2 savings elsewhere.
What does this mean to specifications?
The expectation remains that energy strategies will be developed in accordance with the established energy hierarchy; ‘be lean, be clean, be green’. Fabric standards, already pushed through the introduction of Fabric Energy Efficiency requirements, should be maximised while ensuring necessary overheating mitigation measures and adequate daylight levels are sustained.
This is followed by an increasing need to investigate opportunities for connecting to existing district heating networks, establishing new or making provisions for a future connection. The London Mayor has outlined the city’s objective to source 25% of the heat and power demand from decentralised systems by 2025. This brings the need to ensure that a development’s pipework infrastructure minimises distribution losses and overheating risks, particularly within enclosed and occupied areas.
Utilisation of Combined Heat and Power (CHP) requires technical appraisal to ensure that it is integrated to a scheme where it is shown to be a viable solution. Adequate care must be taken to ensure that CHP units are not incorporated to schemes for the sake of ticking a box when their operation does not fulfil the requirements to achieve savings. We would always advocate seeking advice from a CHP specialist at the earliest opportunity where an opportunity may exist.
The third rung on the ladder relates to renewable technology. These should be appropriate to the building and complement all other systems. Although Part L assessment methodology compliance is important, it is vital that the building functions efficiently in the real-world!
Carbon offset payments
The aforementioned balance between value and cost was defined at the point where CO2 savings were more cost-effective elsewhere. The carbon offset payment is made to the Borough during the development and calculated from the quantity of CO2 (regulated tonnes) for a period of 30 years. The Housing SPG refers to an indicative rate of £60 per tonne for 30 years, payable to each borough. Each London borough is tasked with appraising this figure and establishing their spending infrastructure. Based upon specific research by individual councils, the rate currently varies from £46/tonne to £104/tonne, with the borough of Islington requesting a one-off payment of £920 per tonne. Therefore, early investigations are critical to ensure an accurate cost estimate is known while developing the energy strategy.
Variation in carbon offset prices is largely due to a lapse in research for borough specific operational cost for carbon emissions. Where these consultations have been carried out, the cost per tonne has increased in line with the estimated cost of implementing carbon offset solutions.
Any carbon savings associated with the offset fund should be spent on energy and retrofitting projects within the respective borough, while being mindful of any conflict with the Community Infrastructure Levy (CIL) Regulations. The Mayor’s SPG is quite specific with respect to what these funds should be spent on by stating, ‘The borough should ensure that the off-setting measure provides added value – that is, the measure would be unlikely to be funded through other means’. These offsetting measures will be secured through S106 agreements and potentially pooled to provide quantifiable energy efficiency measures on a greater scale.
There is a risk that limitations that exist within certain developments will prevent on-site CO2 targets from being achieved. In these cases there is expectation that all feasible measures will be incorporated and consultation with the borough will be required when a shortfall is shown to exist.
Beverley Rosso is Senior Sustainability Consultant at Stroma Tech
Stroma Tech has experience in developing energy strategies and the production of energy and sustainability statements. In conjunction with our extensive energy modelling team, Engineers and CIBSE Low Carbon Consultants, we can help you to achieve your targeted CO2 savings.