This policy introduces new levels of energy use that will be allowed for new development and how renewable energy should be used to meet that energy need. It also introduces requirements for the assessment of whole life carbon by new development and address the potential issue of carbon offsetting.
The policy introduces the following parameters for energy use for new buildings in order to achieve Net Zero for Operational emissions:
• A space heating demand of 15-20kwh per meter square per year for residential and non-residential buildings.
• All heating provided through low carbon sources and not fossil fuels with no new development connected to the gas grid.
• All buildings should achieve a total Energy Use Intensity (EUI) target for both regulated and unregulated energy of no more than 35kWh per m2 per year with a range of different EUI targets for non-domestic buildings as set out in the policy.
• New development should generate at least the same amount of renewable energy (preferably on-plot) as they demand over the course of a year and this should include all regulated and un-regulated energy. In large developments the energy generation can be averaged across the development to compensate for the inability of specific dwellings to meet the target
• Offsetting can only be used as a last resort and the building should be future proofed to allow residents or tenants to enable the achievement of net zero dwellings.
• To target Net Zero for Construction residential developments of greater than 150 dwellings or 1,000m2 should calculate the whole life carbon of the development and present measures to reduce these.
Whilst Countryside recognise the importance of addressing climate change, we do have a number of concerns that draft Policy CC/ NZ is unsound on the basis that it is not viable or deliverable and may reduce the delivery of much needed affordable and private housing within the Greater Cambridge (GC) area. We have summarised our concerns below which we hope are helpful to the authorities in their search for sound and effective climate change policies within the GCLP.
• It is noted that the dwelling energy efficiency targets within draft Policy CC/ NZ go significantly beyond building regulations including the proposed Future Homes Standard 2025 although the Topic Paper (page 17) states that the standards proposed are not as onerous as the passivhaus standard but do go beyond the proposed FHS. The passivhaus standard is widely recognised as the highest construction standard that is currently available in the UK for residential development as it requires complex construction techniques and therefore carries a cost premium. Analysis of this standard and others compared to the targets within Policy CC/ NZ have identified the following:
‒ The passivhaus standard requires an EUI of less than 120 kWh m2 per annum compared to the policy target of 35KWh per m2-thereby suggesting that the draft policy target is in fact considerably more onerous than passivhaus.
‒ The EUI within the draft policy CC/NZ appears to have been taken from the recommendations from the London Energy Transformation Initiative (LETI) climate emergency guide which was created to introduce higher standards in Greater London where new development is dominated by low/ high rise apartments that are inherently more energy efficient than typical single and family housing types.
‒ The passivhaus standard requires a space heating demand of 15 kWh m2 per annum compared to a draft policy target of 15 – 20 kWh m2 thereby suggesting close alignment between the two on this specific issue.
‒ Draft Policy CC/NZ requires applicants to address both regulated and unregulated energy as opposed to the FHS which deals with regulated energy alone. The Government have made this important differentiation because the use of unregulated energy (e.g. power used by televisions and appliances) is the responsibility of the homeowner and not the housebuilder and is extremely difficult to quantify accurately at construction stage.
‒ To hit the EUI target of 35KWh per m2 the Evidence base document estimates that the following will be required although no exact details are available:
(a) Low U-values that exceed the requirements of the proposed FHS
(b) Mechanical Ventilation with Heat Recovery (MVHR) to recover waste heat from the dwellings
(c) A high level of air-tightness to prevent cold air ingress and heat loss from the dwelling
All of the measures identified above are characteristic of implementing the passivhaus standard.
‒ The cost of implementing Policy CC/ NZ has been estimated at between 10% and 13% above that required to build to current Building Regulations. No detailed analysis of the assumptions behind this calculation were available however. It is claimed that this cost is achievable on the basis that significant costs are required to implement the FHS and therefore the costs identified by the Evidence base are an over-estimate and are therefore acceptable. Countryside believe it is extremely important to obtain the detailed evidence behind these costs as in our experience the cost of building to passivhaus standards (or extremely close) is likely to be significantly higher than those quoted in the Evidence base paper.
• Given the above it would appear that the Policy CC/ NZ is implementing on-site energy efficiency standards much more closely aligned to passivhaus which presents significant challenges to the housebuilding industry for the following reasons:
‒ Building to passivhaus requires a complete transformation of the on-site construction process and supply chain which would significantly delay housing delivery and increase costs of new dwellings particularly for the small and medium sized house builders.
‒ The cost of constructing houses to passivhaus is likely to be significantly higher than that identified in the evidence base although a direct comparison is difficult in the absence of the detail behind the assumptions in the Evidence Base. Achieving air-tightness levels close to passivhaus and installing MVHR are extremely costly forms of construction.
The GCLP states that it has considered alternatives to the draft policy and targets with one being the use of the Government’s FHS as the principal metric for sustainable housing. Countryside fully support the introduction of the FHS in 2025 as it will deliver many of the strategic requirements of draft Policy CC/ NZ which include:
• An all-electric energy strategy thereby allowing the carbon footprint of the dwelling to fall each year in line with grid decarbonisation
• Dwellings will have very high levels of insulation and likely require triple glazing to ensure maximum heat retention.
‒ Each home built to the FHS will require the extensive use of renewable energy technologies in which are likely to include Air Source Heat Pumps and Photovoltaic cells.
‒ There would a consistent, deliverable standard for all new dwellings in Greater Cambridge thereby providing a level playing field for all housing developers.
Whilst the detailed energy demand / performance metrics for the FHS is unknown at this time the Government have confirmed that dwellings built to this standard will reduce carbon emissions by 75% compared to those built under the current 2013 Building Regulation.
Countryside therefore believe that Policy CC/ NZ of the GCLP should utilise the FHS as the main metric for the construction of energy efficient housing. The use of this standard will also provide greater support to the small and medium (including selfbuild) housing sector which we believe is critical to ensure greater supply and diversity of affordable housing to the consumer.
In addition to the concerns with respect to the on-site standards presented in draft Policy CC/ NZ, Countryside also have reservations with respect to other aspects of the Policy which are:
• It is unreasonable to prohibit all new developments to connect to the gas grid as it is possible that for buildings such as care homes and health facilities gas may still be the most suitable fuel for heating given the bespoke heating requirement of these health facilities. Given that some of Countryside’s sites are large enough (such as Bourn Airfield) to permit the delivery of critical social infrastructure such as schools and health facilities, there may be a technical requirement for gas in some form to our large sites.
• The requirement for new dwellings to generate at least the same amount of renewable energy as they demand over the course of the year is extremely challenging given that it must include both regulated and unregulated energy for which it is difficult to estimate the exact quantum of energy needed given it is entirely dependent on the occupiers use of appliances.
• The offsetting policy (although lacking in detail) would appear to be based on the cost of providing additional PV cells to generate the quantum of energy that remains from the development site after all on-site measures have been deployed. At this time however there appears to be no data with respect to the cost of this offsetting policy and how any money will be spent with absolute certainty to ensure ‘additionality’. Without any costs or viability information this aspect of the policy fails the test of soundness. It is evident however that this policy will add a significant (albeit unknown at this time) cost to new housing which ultimately will feed into higher house prices and greater affordability challenges. We look forward to seeing the detail of this policy but would urge the authorities to fully explore the viability of this carbon offsetting and its impact upon the delivery of affordable housing before it is adopted.
• The requirement to calculate Whole Life Carbon (WLF) in construction would increase the importance of reducing embodied carbon within the supply chain, particularly for small and medium sized developers. Countryside have however already committed to reducing our embodied (scope 3 emissions) within the supply chain and have set ambitious targets to reduce these over time. The requirement to submit a WLC assessment for each application places an unnecessary burden upon our new development activities as this work is already part of our corporate commitments. To ensure this policy does not negatively affect housing delivery we would request that the acceptable evidence to demonstrate policy compliance could be details of our corporate commitment and progress to date.