The Climate Change Act, passed in 2008, committed the UK to reducing greenhouse gas emissions by at least 80% by 2050 when compared to 1990 levels. It did this through a process of setting five year caps on greenhouse gas emissions termed ‘Carbon Budgets’. This approach has now been used as a model for action across the world, and is mirrored by the United Nations’ Paris Agreement.
With the new focus on the quality of homes in the NPPF and the national emphasis on more energy efficient homes, Local Authorities can play a key role in incentivising industry standards and increase building performance. Encouraging greater transparency on building performance not only leads to engagement from customers helping to generate demand for more sustainable homes but goes a long way to providing clarity for the council's decision making process.
This Guide seeks to promote and encourage energy efficiency and sustainable development in even the smallest of projects. This could include choosing locally sourced materials through to the integration of high-technology solutions to minimise energy consumption or generate heat. Including a sustainability statement alongside your planning application which clearly sets out details of your intentions regarding sustainability and energy use can aid and inform the decision-making process.
Materials
Using locally sourced materials reduces transportation requirements whilst also maintaining local character. Clay, flint, timber, reed and straw are all readily available within Norfolk (see materials section for more details). Maximising the use of reclaimed or recycled materials offers an inherently sustainable approach to development with often desirable and highly contextual end results. The table below shows common reusable and recyclable materials.
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Maximising use of materials with low embodied energy is another means of reducing carbon footprint in the development process. This idea of embodies energy considers the amount of energy required to make and transport a product. For example, products which have long manufacturing processes, such as plastics, have high-embodied energy because they use up fuel and other resources. Timber, which in some cases only need sawing before its ready for use, has low embodied energy. Often manufactures now label products, so you can ensure materials come from sustainable sources.
Renewable and Low Carbon Technologies
The opportunity for developments to incorporate renewable and low carbon energy sources will differ, as the viability of these technologies will be affected by the physical nature of the development such as aspect, building height and the amount of open space. Early discussions with the planning authority are recommended, and a feasibility study should be undertaken by an energy specialist in order to establish the most appropriate energy source(s) for the new development.
Solar Water Heating
These use a heat collector, usually mounted on a roof, which contains a fluid that is heated by the sun. The heated fluid is then passed through a coil in a hot water storage cylinder and this water can then be used immediately or raised to a higher temperature (if required) by a boiler. A well designed system can contribute between 40-50% of a household’s yearly hot water requirements, but they perform best in summer, which can avoid the need to run boilers at low loads when they are not as efficient. Careful consideration should be given to their siting to ensure maximum solar exposure and minimum overshadowing.
Developer considerations include:
- Larger than average hot water cylinders are required to maximise the efficiency of the system, which will need to be reflected in airing cupboard design.
- Between 2-5m3 of south facing roof space will be required, which should not be shaded by trees or other buildings.
- Future proofing to enable solar hot water collectors to be added at a later date should include dual coil, appropriate sized hot water tanks, and a compatible boiler.
Photovoltaic Cells (PVs)
These cells convert the sun’s heat directly in to electricity and can be incorporated on most buildings as tiling or cladding. Again, careful consideration should be given to their siting to ensure maximum solar exposure and minimum overshadowing, as this can reduce the efficiency of the cells markedly. They are well suited to use in large offices as the energy supply is at a maximum during the period of maximum building operation, whereas generally domestic dwellings have a maximum demand between 6pm and 10pm when the sun is low in the sky or set. PVs have a longer payback period than both solar hot water heating and wind turbines as they are less efficient, and as they are particularly affected by overshadowing, careful site survey and feasibility studies should be undertaken before considering them as part of the renewable energy solution for a building.
Developer considerations include:
- PVs should be mounted on facades facing SE-SW and at an elevation of between 30-40 degrees (this angle also helps keep them clear of debris).
- They should only be used where they will be completely un-shaded.
- Future proofing to enable PV cells to be added at a later date would need to ensure the roof structure could support the weight of the cells.
Small Scale Wind Turbines
These can either be building mounted (micro scale) or free-standing, grid-connected or stand alone. Reliable estimates of windspeed at the proposed site should be obtained as part of the
feasibility study. The Department of Business Enterprise and Regulatory Reform wind speed database contains estimates of the annual mean wind speed throughout the UK. However it is very unlikely to give an accurate idea of wind speed at a proposed site for a small wind system, particularly in urban or built up areas, and if wind speed at the site is not in the range
at which the small wind system capacity is rated then the system may deliver less electricity than expected. This data can only be used as a guide and should be followed by on-site
measurements for a proper assessment. Generally, sites need an average windspeed greater than 4.5m/s although roof mounted turbines can work at speeds as low as 3.5m/s. With the
exception of micro building-mounted turbines, wind turbines need to be sited away from buildings to ensure that the airflow is as undisturbed as possible.
Developer considerations include:
- Determine the average windspeed onsite as part of the feasibility study.
Biomass
Biomass boilers burn the chipped or pelleted products of forestry operations or short rotation coppice. They can be used to provide both space and hot water heating and range in scale from simple manual fed domestic stoves to boilers to suit any development, whatever its size. Both the woodchip and pelleted forms can be automated, requiring no day-to-day attention and maintenance is of a low level, routine nature.
Developer consideration include:
- Dry storage space is required for the fuel.
- These systems are likely to require more frequent maintenance so provision needs to be made for an auxiliary heating when maintenance is required and for removing and disposing of ash.
- Future proofing for use of this technology should include ensuring buildings already have a flue fitted, especially now that most new developments do not have chimneys. Developers should also ensure there is sufficient space for biomass storage.
Low Carbon Technologies
Heat Pumps
These work on the same principle as refrigeration units, by generating heating or cooling through exploiting naturally occurring heat differences in different mediums: Heat pumps then increase the temperature to provide a more useful output temperature of around 40-50oc which are best used with low temperature heating systems such as under-floor heating. Whilst heat pumps can provide 100% of a dwellings heat requirements, they will usually only pre-heat domestic hot water so another form of hot water heating will be required. Heat pumps do require some power to operate so they can only be considered 100% renewable if the power to operate the pump comes from a renewable source.
Ground source heat pumps
These use the natural heat in soil to provide heating and cooling. The temperature in the soil is just about constant at 12oc all year round in the UK. Water, sometimes containing a refrigerant, is pumped through a series of underground pipes absorbing the ground's heat.
Air source heat pumps
They derive their heat from the ambient air or sometimes from exhaust air in a controlled ventilation system. Those deriving heat from exhaust air will generally produce higher efficiencies as the heat pump will need to do less work to upgrade the temperature.
Developer considerations include:
- They are best used where high levels of energy efficiency have been incorporated into the building design and where under floor heating is to be used.
- Future proofing for ground source heat pumps should ensure that the foundations are stable enough for the ground loop to be fed down.
Electric Vehicle Charging
The Automated and Electric Vehicles Act 2018 came into effect on 19th July 2018. It gave the Government new powers to improve public chargepoint availability, for example by ensuring that motorway services are upgraded with plenty of points, and improving consumer confidence in charging their vehicles by:
- making sure that public charge points are compatible with all vehicles
- standardising how they are paid for
- setting standards for reliability
Types of Charging
Currently there are three levels of charging capability, notably:
- Standard chargers - typically rated at 3kw and can fully charge a vehicle in 6 – 8 hours and are best suited for overnight charging. This is the standard used for residential properties as they can be installed as part of the electricity supply without any additional capacity on a distribution board.
- Fast chargers - typically rated between (7-22kW) and can fully recharge some models in 3-4 hours.
- Rapid DC chargers - typically rated at 50kW and can charge an EV to 80% charge in 30 minutes (depending on battery capacity).
As technology advances there may be changes to these figures, and regard should always be had to the latest best available. Development proposals should specify the type or types of chargepoints to be installed.
Proposals for development should include, where practical, appropriate provision for electric vehicle charging points. Electric vehicle parking spaces should be counted as part of the total parking provision and bays should be clearly marked. The delivery of chargepoints should not exclude parking space provision for people with disabilities. Proposals should specify the type or types of chargepoints to be installed.
Residential developments (excluding use class C1 hotels and C2 residential institutions) require, where private driveways and garages are provided, 1 *active charging point per unit (an external charging point on a driveway or a wall mounted internal charging point in a garage). Where off-plot or communal parking is provided a minimum of 50% of spaces should have **passive charging points.
Non-residential developments, Use Class C2 residential institutions and proposals for stand-alone car parks, should include *active provision for electric vehicle charging points of a minimum 1 charging point or 20% of all new parking spaces, whichever is the greater.
Use Class C1 Hotels should include *active provision for electric vehicle charging points of 30% of all new parking spaces.
For major developments, details of how the required electric vehicle charging points will be allocated, located and managed should, where applicable, be included within the relevant Transport Assessment or Transport Statement. The management of the charging points, including the mechanism/procedure for taking payments, will be the responsibility of the developer/occupier.
In cases where charging points, including infrastructure to enable retrofitting, cannot be provided within the development site, developer contributions may be sought to enable those facilities to be suitably provided in other locations including public car parks or on-street parking spaces.
Large developments with dedicated electricity sub-stations should specify the sub-station to a sufficient capacity to fully cater for all electric vehicle charging requirements.
*Active chargepoints are fully wired and connected, ready to use points at parking spaces. **Passive provision requires the necessary underlying infrastructure (e.g. capacity in the connection to the local electricity distribution network and electricity distribution board, as well as cabling to parking spaces) to enable simple installation and activation of a chargepoint at a future date.
Vehicle charging points at Holkham Estate