Written evidence from NHBC
- NHBC itself has been at the forefront of policy development for zero carbon homes. Our contributions include through the Zero Carbon Hub – set up in partnership with Government to design a path to a zero-carbon future for new homes.
- To explore what the non-gas home of 2025 might look like, the NHBC Foundation published a report titled: The Future for Home Heating – life without fossil fuels. This research indicates that electric heat pumps will likely become the predominant method of heating homes to achieve net zero by 2050.
- The technologies required to reach net zero will need well-trained skilled professionals to install them into new homes. New skills and competencies must be developed as well as a continued drive to recruit more people into the sector. If not addressed, this could lead to delays in the supply chain and sub-standard installations.
- The Foundation also published: Biodiversity in new housing developments: creating wildlife-friendly communities. It explores the practicalities of building new homes in a sustainable way that enhances wildlife and develops climate resilience.
- NHBC believes that local planning authorities (LPAs) should not have a determining role in energy efficiency targets. Technical standards are best suited to be explained in building regulations. If they are duplicated in planning this can cause a conflict and inconsistency which should be avoided.
NHBC would be happy to give oral evidence to the Committee to expand on these points.
- How can materials be employed to reduce the carbon impact of new buildings, including efficient heating and cooling, and which materials are most effective at reducing embodied carbon?
Role of Heat Pumps in achieving net-zero emissions
- Heat pumps can operate with upwards of 200% efficiency, (often as high as 400%), providing up to four times as much heat to the home as the electricity that they consume from the grid by using a fluid compression/expansion process to move extra ‘free’ heat from the colder outside environment to the interior of the home.
- The high efficiency of heat pumps results in considerably lower emissions and greatly reduced running costs for the residents.
- Importantly, electric heating systems other than heat pumps are also unlikely to comply with the proposed primary energy performance targets in future Building Regulations.
- Research from a previous NHBC Foundation report ‘House building: a century of innovation’, published in October 2019, found that heating systems powered by heat pumps operate at a lower temperature than gas boiler systems and are suited to well-insulated new homes with substantially reduced demand.
- Reasons behind the low uptake of heat pumps include historical issues where heat pumps have not performed well, resulting in resistance to increased uptake.
- For example, there have been problems when a heat pump is providing domestic hot water, but, as the Foundation report found, many of these issues ultimately came down to bad design, installation and/or commissioning.
- It is therefore vital that specialist advice is sought from a suitably qualified and experienced heating designer.
- Choosing the right type of heat pump for a property is also important to increased uptake which the Foundation report goes explores at some length.
- In practice, for most UK housing there is a choice of two basic types of heat pump: air-source and ground-source. While both types of heat pump can in principle distribute the heat around the home, the choice of which type of heat pump and system depends on the built form, size, tenure and location of the home.
- NHBC believes that to ensure heat pumps are used in the most effective places, consideration should be given to ensure they have been effectively designed, specified, installed, and commissioned by professionals.
- New skills and competencies must be developed as well as a continued drive to recruit more young people into the sector. If not addressed, this could lead to delays in the supply chain and sub-standard installations.
- What role can nature-based materials can play in achieving the Government’s net zero ambition?
- We have a proven track record of supporting house builders and developers on sustainability and environmental matters. From the Zero Carbon Hub to the ongoing work of the NHBC Foundation, we have led the way with research and practical guidance, solving problems together with the industry and government.
- NHBC recently published a report: ‘Biodiversity in new housing developments: creating wildlife-friendly communities’. It explores the practicalities of building new homes in a sustainable way that enhances wildlife and develops climate resilience.
- The report offers several nature-based solutions to some of the following main environmental challenges:
- Pollinator decline – Nectar-rich landscape with more deciduous and herbaceous plants and less evergreens with little or no nectar value
- Carbon emissions – Vegetation cover
- Water pollution – SuDS (Sustainable drainage systems) source control, soft landscaped SuDS features
- Soil erosion – Vegetation cover, less mowing and soil disturbance
- Water run-off/localised flooding – Vegetation cover and SuDS
- Further to achieving the Government’s net-zero ambitions, nature-based materials such as trees improve the quality of life for communities and provide a wide range of benefits beyond achieving net zero.
- Research shows that where tree canopy cover is over 25% but open enough for people to feel safe (and not suppress the vegetation beneath), social deprivation and crime are lower, plot values are higher, and there are education and employment benefits.
- What role can the planning system, permitted development and building regulations play in delivering a sustainable built environment? How can these policies incentivise developers to use low carbon materials and sustainable design?
- NHBC believes that reference to technical development matters in Local Plans should be restricted to those considered appropriate by the Government as a minimum provision within the Approved Documents or through allowable optional requirements.
- This will avoid complexity and aid parity/consistency of application across the country.
- If this was not the case, problems would arise over minimum standards. For example, if the planning authority can set higher levels this creates inconsistency for developers operating across different local authorities and with duplication of work.
- There is also the danger that if the requirements are inconsistent that there will be misinterpretation of what is required, and this would cause unnecessary duplication.
- NHBC believes that to ensure consistency and clarity, local planning authorities should not have a determining role which would be better placed with building regulations only.
- Technical standards belong in building regulations to be explained; if they are duplicated in planning this can cause a conflict, which is especially true of energy efficiency where the technical expertise is with a building control body rather than planning authority.
- Energy requirements are a complicated issue and setting standards through local plans or conditions can often lead to problems in demonstrating compliance due to lack of understanding which would later conflict with national standards.
- For example, we have evidence of requirements being set for renewable technologies that would not demonstrate performance against the new standards and create difficulty in compliance for both.
- How well is green infrastructure being incorporated into building design and developments to achieve climate resilience and other benefits?
- As previously mentioned, the NHBC Foundation report ‘Biodiversity in new housing developments: creating wildlife-friendly communities’ explores how green infrastructure can improve climate resilience and connect people with nature.
- The report explains that appropriately designed and implemented green infrastructure has an important but not yet properly understood role in responding to the climate crisis.
- This is both in terms of reducing the impacts of climate on us at a local scale and helping to absorb carbon from the atmosphere.
- Green roofs
- Green roofs are increasingly being used in urban apartment developments. As well as helping insulate buildings, they reduce rainfall run-off by up to half, and contribute to cooling the local atmosphere.
- Where solar panels are installed on a green roof, the efficiency of the solar panels is improved as vegetation around them helps maintain their optimal operating temperature.
- Sustainable drainage systems (SuDS)
- SuDS mimic natural processes in managing rainfall using landscape form and vegetation such as trees, shrubs, flowering plants and grassland.
- SuDS that use soft landscape features have lower installation and maintenance costs than hard engineered solutions.
- Flow control and limit volumes of surface water to reduce risks of downstream flooding.
- Improved water quality by trapping silts and reducing pollution of water courses and bodies.
- Groundwater recharge which helps maintain river flows and support wetlands.
- Increased evapotranspiration thereby helping climate regulation in urban areas.
- Increased opportunities for wetland wildlife in urban areas and links to the wider landscape.
- Help to well-being by increasing the amenity value of the public realm.
- Nest sites for birds
- Having been significantly affected by changes to buildings, birds can readily be helped by providing external or integral nest features.
- Provision of integral nest sites for birds is through hollow chambers fitted into the fabric of a building while in construction.
- There are several commercially available products that are discrete and fit in with the brickwork etc of the building.
- Fitting at a ratio of 1 nest brick per house across a development will ensure sufficient nest sites for colonial species. Up to five birds can be located in one house, so helping locate them in suitable locations for access to foraging habitat.
- How should we take into account the use of materials to minimise carbon footprint, such as use of water harvesting from the roof, grey water circulation, porous surfaces for hardstanding, energy generation systems such as solar panels?
- To explore what the future home might look like, the NHBC Foundation commissioned and published a research report in June 2018 titled: Futurology: The new home in 2050.
- The Foundation report notes that technology will transform the home into a collector and storer of energy as pressure continues to grow on natural resources.
- Heat storage, in the form of thermal stores, will play a greater part; enabling the home to heat hot water when the sun is shining or when energy is cheap.
- Hot water consuming devices may operate intelligently when the stores are sufficient or heat water themselves when tariffs are low.
- The increasing uptake of electrical heating and hot water will also encourage the coupling of photovoltaic arrays with the home’s heating system.
- In the very long term that a mix of approaches might ultimately lead to the development of homes that mimic natural systems. These could be built from materials that are self-repairing and provide internal environments that are entirely self-regulating, responding to environmental changes.
- The report concluded that substantial technological advancement would take place in response to societal, demographic and climate changes.
 Further information on the Zero Carbon Hub is available online here: https://www.zerocarbonhub.org/