Net Zero Carbon Development Plan Document - Regulation 19
6 Reducing Energy Demands: Energy Efficient Buildings
Policy NZC2(A): Making buildings energy efficient
New development of one or more new dwellings (C3 or C4 use) are expected to demonstrate a 10% improvement on the Part L 2021 Target for Fabric Energy Efficiency (set by SAP10.2).
New developments of 1,000sqm or more of new non-residential floorspace, hotels (C1 use class), or residential institutions (C2 use class) are expected to demonstrate that they achieve a 19% reduction in carbon emissions compared to Part L 2013 through energy efficiency measures (fabric efficiency, efficient services and efficient energy supply; steps 1 and 2 of the energy hierarchy).
Where full compliance is not feasible or viable having regard to the type of development involved and its design, proposals must demonstrate through the energy statement that carbon reductions to the greatest extent feasible through energy efficiency measures have been considered and incorporated.
All energy statements must also lay out the U-values and airtightness of the proposed building in comparison to the notional values in the Future Homes Standard or Future Building Standard (indicative specification, or final, as available at time of application).
6.1 The energy efficiency of buildings has a significant part to play in achieving the Council's net zero aims, but it also carries wider benefits for consumers and the country at large. We know that, in addition to reducing CO2 emissions, energy efficient homes minimise energy bills, provide healthier and more comfortable environments to live in, and ensure that we are making the best use of energy resources which in turn will help facilitate a faster transition to low carbon energy sources for all.
6.2 The Standard Assessment Procedure (SAP) is the methodology used by the Government to assess and compare the energy and environmental performance of dwellings.
6.3 To demonstrate compliance with policy NZC2(A), calculations should be performed using the latest version of the SAP 10.2 methodology (current version 20.08.2021). Government has confirmed that this calculation will become the statutory methodology by June 2022 along with the interim uplift to Part L.
6.4 All developments must demonstrate the extent to which compliance with Policy NZC2(A) is achievable through an energy statement. It is acknowledged that it may not be feasible for some types of commercial development (hotels and schools) to achieve the 19% carbon reduction from energy efficiency measures, due to high peak hot water demand and will be considered on a case-by-case basis.
6.5 The 10% improvement in dwellings is set to reflect the approximate uplift to building fabric (U-values and airtightness) between Part L 2021 and the indicative Future Homes Standard 2025. There is national government estimated cost data on the achievement of these fabric measures, which has been taken into account in the whole-plan viability assessment.
6.6 The 19% improvement for non-residential dwellings reflects that and which evidence has identified is demonstrably feasible and viable in Milton Keynes.
6.7 To demonstrate compliance with this policy, development proposals should provide data that is consistent with the building performance metrics set out in the Government's response to the Future Homes Standard consultation (January 2021) or any subsequent set of metrics required through the Building Regulations. At the time of drafting this policy, this requires four metrics to be provided:
- Primary energy target
- CO2 emission target
- Fabric energy efficiency target
- Minimum standards for fabric and fixed building services.
The use of these metrics will ensure consistency and clarity in the way data is collated and set out.
6.8 The approach focuses on a fabric first methodology to ensure the maximum benefits of passive and low energy design and technology can be achieved. This serves to reduce energy demand and minimise lifecycle cost.
6.9 In addition to the requirements of this policy, proposals for dwellings should consider how to make best use of site orientation, building form, layout, landscaping and materials to maximise natural light and heat, whilst avoiding internal overheating by providing passive cooling and/or mechanical ventilation, thus reducing potential overheating and reliance on air conditioning systems.
6.10 On all new dwellings and commercial development over 1,000sqm it will be expected that the development is tested through the most up to date SAP calculations to demonstrate the performance gap between design and construction. These calculations would take place in accordance with the methodology set out in paragraph 5.9 For sites of over 10 dwellings where standard house types are used, a sample of at least 20% of all dwellings (and including all house types) shall be tested.