Designing and specifying pipework to meet Future Homes and Buildings Standards
The Future Homes and Buildings Standards (FHBS) were published in March 2026 and are due to come into force in England in March 2027 and introduce new legislation designed to increase energy efficiency and lower greenhouse gas emissions from all types of new construction in England. For new residential buildings, this will be known as the Future Homes Standard (FHS); for new non-domestic buildings, the Future Buildings Standard (FBS). Scotland and Wales have their own devolved regulations aimed at achieving a similar outcome.
The FHBS represents a significant shift towards more energy-efficient, low-carbon buildings, placing greater emphasis on building fabric, energy performance and low-carbon heating during design and construction. It aims to make new homes and buildings zero-carbon-ready at the construction stage, in preparation for a fully decarbonised grid, so that they will not need to be retrofitted to meet future carbon targets. The FHBS applies to new buildings only so work on existing buildings is not affected by the new regulations. However, some specified building work and those higher risk buildings may be affected by the new regulations.
The new regulations place a strong focus on thermally efficient building fabric and are intended to:
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Deliver a 75-80% reduction in carbon emissions for new dwellings compared to the previous 2013 Part L standards
- Use low-carbon heat sources rather than traditional fossil fuels, which will not provide a compliant solution
For pipework designers and specifiers, these two features will inform the most appropriate route to compliance, as explored below.
Why do the Future Homes and Buildings Standards place more emphasis on pre-insulated pipework?
Pre-insulated pipework can play an important role in meeting the energy-efficiency objectives of the FHBS. By reducing heat loss from warm-water pipework and limiting heat gain in cold-water systems, effective insulation helps minimise energy losses across the distribution system.
This is particularly important because buildings under the FHS must use low-carbon heating systems, such as heat pumps which generally operate at lower temperatures. Consequently, heat lost from distribution pipework represents a greater proportion of the energy used and can have a more significant impact on overall system efficiency.
In multi-occupancy buildings, domestic hot water (DHW) can become one of the largest areas of energy demand. As a highly efficient building fabric reduces the energy required for space heating, DHW accounts for a greater share of overall energy consumption, making the design and specification of the DHW distribution system increasingly important.
A well-designed system that minimises complexity and pipework lengths wherever possible can reduce distribution losses and improve overall efficiency. Specifying high-performance pre-insulated pipework can further limit heat loss and energy consumption while supporting the efficient operation of low-carbon heating systems.
Considering pipework routing, system design and insulation performance early can help maintain energy efficiency throughout the distribution system.
Which part of the FHBS regulations covers pipework systems?
The 2026 edition of Approved Document L, 'Energy and greenhouse gas emissions', which supports the Future Homes and Buildings Standards, specifically addresses heat loss and heat gain from pipework. Requirement L1 states that reasonable provision must be made to conserve fuel and power and minimise greenhouse gas emissions by limiting heat gains and losses through thermal elements and other parts of the building fabric, and from pipes, ducts and vessels used for space heating, space cooling and hot water services.
This makes pipework an explicit consideration in the energy-efficiency requirements of Part L, rather than simply an installation detail.
Part L requires primary circulation pipework serving heating circuits and DHW systems to be insulated, including pipework that passes outside the building envelope.
Table 3.4 specifies the minimum insulation thicknesses:
This makes pipework an explicit consideration in the energy-efficiency requirements of Part L, rather than simply an installation detail.
Part L requires primary circulation pipework serving heating circuits and DHW systems to be insulated, including pipework that passes outside the building envelope.
Table 3.4 specifies the minimum insulation thicknesses:
| Nominal internal pipe diameter (mm) | Minimum insulation thickness(1) (mm) for low temperature hot water systems |
|---|---|
| Less than or equal to 25 | 20 |
| Less than or equal to 100 | 24 |
| NOTE: 1. Thicknesses apply for insulation with a thermal conductivity of 0.035W/(m·K) or better. For other circumstances, consult BS 5422. |
|
The guidance also encourages enhanced insulation where this can further reduce heat loss.
This requirement is particularly relevant to buildings connected to low-carbon heat networks. Heat losses must be controlled both in the pipework within the building that runs to the heat interface unit (HIU) in each home and in distribution pipework carrying heated or cooled water beyond the thermal envelope.
High-performance pre-insulated pipework can make an important contribution here and should form part of the overall energy strategy. Pre-insulated pipe-in-pipe can carry both warm and chilled water and limit heat transfer between them where networks provide both heating and comfort cooling. Reducing distribution losses minimises the energy that must be generated, improves system efficiency and supports wider low-carbon performance targets.
This requirement is particularly relevant to buildings connected to low-carbon heat networks. Heat losses must be controlled both in the pipework within the building that runs to the heat interface unit (HIU) in each home and in distribution pipework carrying heated or cooled water beyond the thermal envelope.
Why does the Future Homes and Building Standards increase the importance of controlling heat losses from pipework?
High-performance pre-insulated pipework can make an important contribution here and should form part of the overall energy strategy. Pre-insulated pipe-in-pipe can carry both warm and chilled water and limit heat transfer between them where networks provide both heating and comfort cooling. Reducing distribution losses minimises the energy that must be generated, improves system efficiency and supports wider low-carbon performance targets.
What are the benefits of using GF's pre-insulated pipework for FHBS projects connected to heat networks?
With the next generation of Uponor Ecoflex VIP 2.0, GF has introduced highly efficient, flexible pre-insulated pipes for FHBS projects using medium- to large-scale local heat distribution networks. In these applications, minimising the external pipe diameter can provide significant installation and logistical benefits.
The combination of high-performance insulation and compact construction helps reduce the energy lost during heat distribution, supporting the overall efficiency of low-carbon heating and cooling systems.
Available in diameters from 25 mm to 160 mm, the Ecoflex VIP 2.0 range provides a versatile solution for local and district heating and cooling applications, combining reduced heat loss with installation efficiency and a compact system design.
High thermal performance of GF's Ecoflex VIP
Ecoflex VIP 2.0 uses adapted vacuum insulation panel (VIP) technology to achieve a thermal conductivity (lambda value) of just 0.004 W/mK. This can reduce heat losses by up to 60% compared with conventional flexible pre-insulated pipes.The combination of high-performance insulation and compact construction helps reduce the energy lost during heat distribution, supporting the overall efficiency of low-carbon heating and cooling systems.
Faster and easier installation of GF's Ecoflex VIP
Ecoflex VIP 2.0 pipes can have a 70% smaller jacket size compared to similar heat loss and jacket size with pipes with PE insulation making them easier to handle and install, particularly where space is restricted. Installation time can be reduced by up to 20% compared with hard-foam-insulated flexible pipes and by more than half compared with steel pipe systems. The flexible construction can also reduce the need for joints and fittings, helping to simplify installation and potentially reduce excavation and reinstatement requirements.Available in diameters from 25 mm to 160 mm, the Ecoflex VIP 2.0 range provides a versatile solution for local and district heating and cooling applications, combining reduced heat loss with installation efficiency and a compact system design.
How can a pipework system's compliance with the FHBS be demonstrated?
A pipework system is not assessed for FHBS compliance in isolation. Its contribution forms part of the building's overall energy-performance assessment, supported by appropriate insulation, system design and evidence that the installation has been constructed in accordance with the approved design.
Demonstrating FHBS compliance through whole-building energy assessment
The energy performance of a new multi-occupancy dwelling is assessed using the methodology specified for the FHS. This will initially be SAP 10.3 and will move on to the Home Energy Model (HEM) when it becomes available. The assessment considers the building as a whole, including the performance of its heating and hot water systems and the energy losses associated with distribution.For non-domestic projects under the FBS regulations, the Simplified Building Energy Model (SBEM) or Dynamic Simulation Models (DSMs) can be вused to demonstrate that the proposed building meets energy-efficiency and carbon-emission targets. All mechanical services pipework should be insulated in accordance with BS 5422 and BS 5970.
Building-level evidence packs for FHBS compliance
A clear evidence pack should be produced to demonstrate the quality, compliance and correct installation of building services, including pipework systems. Photographic records should be taken before pipework and other components are concealed by flooring, plasterboard or other finishes.
The evidence pack should clearly show key installations, including primary circulation pipework, cylinder connections, underfloor heating manifolds and heat emitters. Photographs should also demonstrate that primary circulation pipework, including sections passing through walls, floors and service voids, has been properly and continuously insulated. Particular attention should be given to joints, fittings and connections, where inadequate insulation can increase heat loss.
For low-carbon heating systems, commissioning should also confirm that the system operates as designed, with appropriate flow rates, balancing and control settings.
GF's project team can provide design advice and installation-stage training to help ensure that the design performs as intended. The team can also support commissioning so that pipework systems meet FHBS requirements.
The evidence pack should clearly show key installations, including primary circulation pipework, cylinder connections, underfloor heating manifolds and heat emitters. Photographs should also demonstrate that primary circulation pipework, including sections passing through walls, floors and service voids, has been properly and continuously insulated. Particular attention should be given to joints, fittings and connections, where inadequate insulation can increase heat loss.
FHBS installation and commissioning requirements
The specified performance can be achieved only if the pipework system is correctly installed. Installation should follow the approved design, with continuous insulation around the system and particular attention paid to joints, valves, fittings and penetrations, where heat loss can otherwise occur.For low-carbon heating systems, commissioning should also confirm that the system operates as designed, with appropriate flow rates, balancing and control settings.
GF's project team can provide design advice and installation-stage training to help ensure that the design performs as intended. The team can also support commissioning so that pipework systems meet FHBS requirements.
How can GF support projects designed to meet the Future Homes and Buildings Standards?
As well as supplying pre-insulated Uponor Ecoflex VIP 2.0 pipes for buildings connected to heat networks, GF has a long-established track record of providing pipework solutions that enable water to flow efficiently within buildings.
A recent project illustrates the benefits of GF's approach, as Diana Puiu, Business Development Manager, South from GF explains, “We were pleased to supply GF products and technical support to help meet the ambitious sustainability targets for new student accommodation at a renowned college in Oxford. The project is designed to achieve a 40% reduction in carbon emissions compared with current Part L requirements, meet the Passivhaus Low Energy Building standard and contribute to the University’s ambition to achieve net zero carbon by 2035.
To support these objectives, the project uses Uponor Ecoflex Thermo VIP Single, Ecoflex Thermo VIP Twin and Ecoflex Aqua VIP Twin pre-insulated pipe systems. The low-heat-loss pipework distributes water from air-source heat pumps, helping to minimise distribution losses and maximise the efficiency of the low-carbon heating system. This is exactly the type of approach that makes GF well placed to advise customers considering solutions that meet the energy-efficiency and low-carbon requirements of the Future Homes and Buildings Standards.”