New Build Energy Standards: Market Transition Update
Published by New-Builds Team
The UK new build housing sector is in the midst of its most significant energy standards transformation in a generation. The transition from Part L 2021 building regulations to the forthcoming Future Homes Standard (FHS) represents a fundamental shift in how homes are designed, constructed, and heated. For buyers, developers, and investors, understanding the pace and implications of this transition is critical. As of early 2026, the industry is navigating a complex landscape of regulatory deadlines, supply chain challenges, and rapidly evolving construction technologies that will determine how millions of future homes perform for decades to come. The stakes are enormous: the built environment accounts for approximately 25% of total UK carbon emissions, and achieving net zero by 2050 depends heavily on ensuring every new home built from now on meets drastically higher energy performance thresholds.
The journey to this point has been marked by a series of incremental regulatory tightenings, each requiring developers to invest in new materials, technologies, and skills. Part L 2013 set a baseline; the 2021 interim update raised the bar by requiring a 31% reduction in CO2 emissions compared to the previous standard. Now, the full Future Homes Standard promises to push new homes to produce 75-80% fewer carbon emissions than Part L 2013 levels, effectively mandating the end of gas boilers in new properties and requiring fabric-first design principles combined with low-carbon heating systems. This article provides a comprehensive market update on where the industry stands today, which developers are leading the way, what challenges remain, and what buyers should expect when purchasing a new build home in 2025-2026 and beyond.
The Future Homes Standard Timeline
The Future Homes Standard has been the defining policy framework for the new build sector since the government first consulted on it in 2019. After multiple rounds of consultation, interim updates, and the introduction of Part L 2021 as a stepping stone, the full FHS is now confirmed for implementation. Understanding the precise timeline is essential for buyers who may be purchasing homes that straddle regulatory boundaries, and for developers who must plan construction programmes years in advance.
Part L 2021: How the Industry Has Adapted
Part L 2021, which came into force in June 2022, has now been the operational standard for almost four years. It represented a substantial uplift from Part L 2013, demanding a 31% reduction in carbon emissions for new dwellings. The building regulations specify minimum standards for thermal fabric performance, heating system efficiency, airtightness, and the methodology used to calculate energy performance through the Standard Assessment Procedure (SAP 10).
The shift to SAP 10 was itself significant. Unlike its predecessor SAP 2012, the updated methodology uses more favourable carbon factors for electricity (reflecting the increasingly decarbonised grid) while penalising gas heating more heavily. This single change made heat pumps considerably more attractive in SAP calculations and signalled the direction of travel for the industry.
Key Changes Under Part L 2021
| Element | Part L 2013 | Part L 2021 | Change |
|---|---|---|---|
| External Wall U-value | 0.26 W/m²K | 0.18 W/m²K | 31% improvement |
| Floor U-value | 0.18 W/m²K | 0.13 W/m²K | 28% improvement |
| Roof U-value | 0.13 W/m²K | 0.11 W/m²K | 15% improvement |
| Window U-value | 1.40 W/m²K | 1.20 W/m²K | 14% improvement |
| Air tightness target | 10 m³/hr/m² | 8 m³/hr/m² | 20% improvement |
| PV requirement | Not required | Strongly incentivised in SAP 10 | New incentive |
The industry has largely adapted to Part L 2021, though the transition was not without pain. NHBC data from 2024 shows that approximately 93% of new registrations were fully compliant within the first 18 months, with the remaining 7% consisting primarily of developments that had filed building notices before the June 2022 cut-off and were completing under transitional arrangements. By early 2026, virtually all new homes being delivered are Part L 2021 compliant at minimum.
Heat Pump Adoption: Accelerating but Uneven
Perhaps the most visible element of the energy standards transition is the shift from gas boilers to heat pumps. Air source heat pumps (ASHPs) have become the default low-carbon heating technology for new build homes, and their adoption rate has accelerated dramatically over the past three years. However, the picture varies considerably by developer size, housing type, and region. The Microgeneration Certification Scheme (MCS) and BEIS (now DESNZ) data paint a detailed picture of where the industry stands.
The data tells a clear story: heat pump adoption is accelerating rapidly but remains heavily skewed by developer size. The top 10 volume builders, who account for roughly 45% of new housing output, have been the most aggressive in switching, partly driven by their ability to negotiate bulk purchasing deals with heat pump manufacturers and their scale to invest in retraining programmes. Companies like Barratt Developments (now Barratt Redrow following the 2024 merger) have committed to making heat pumps standard across all new developments, while Berkeley Group has led on communal ground-source heat pump networks for apartment schemes.
Mid-tier and SME builders face greater challenges. The additional cost of a heat pump installation compared to a gas combi boiler (typically £4,000-£7,000 per unit after accounting for the hot water cylinder requirement), combined with the need for specialist installers and different site infrastructure, has slowed adoption among smaller firms. The Federation of Master Builders (FMB) has reported that 42% of its members cite heat pump supply chain concerns as their primary barrier to adoption, followed by a shortage of trained MCS-certified installers at 37%.
Heat Pump Cost Impact on New Build Prices
| Cost Component | Gas Boiler Route | Heat Pump Route | Difference |
|---|---|---|---|
| Heating system equipment | £1,800 | £5,500 | +£3,700 |
| Hot water cylinder | N/A (combi) | £800 | +£800 |
| Installation labour | £1,200 | £2,200 | +£1,000 |
| Underfloor heating (recommended) | Optional | £2,500 | +£2,500 |
| Enhanced fabric (reduced by savings elsewhere) | Baseline | -£500 | -£500 |
| Total additional cost per unit | - | - | +£4,500-£7,500 |
Source: NHBC Foundation / Home Builders Federation estimates, 2025. Costs vary by development scale, region, and specification.
The question of whether these additional costs are passed on to buyers or absorbed by developers is nuanced. Research by Savills and the Home Builders Federation suggests that approximately 40-60% of the additional cost is absorbed by developers through reduced margins, with the remainder reflected in higher selling prices. However, this is offset for buyers by lower running costs and improved EPC ratings that unlock green mortgage products with preferential rates. Over a 25-year mortgage term, the energy savings from a heat pump can exceed the additional capital cost by a factor of two or more, making the whole-life cost case compelling.
EPC Performance: Industry-Wide Improvements
The combined effect of Part L 2021 and increasing heat pump adoption has been a measurable improvement in the EPC ratings of new build homes across the UK. Analysis of the DLUHC EPC register data reveals a clear upward trajectory in average ratings over the past five years.
The average SAP score for new build homes has risen from 81 to 88 over four years, representing a steady improvement that reflects both regulatory uplift and voluntary over-compliance by forward-thinking developers. Notably, the proportion of new builds achieving an A rating (SAP 92+) has grown from just 4% in 2021 to approximately 14% in 2025, driven primarily by developments that combine heat pumps with solar PV and enhanced fabric specifications.
EPC Distribution: New Builds vs Existing Stock
| EPC Band | New Builds 2025 (%) | All Existing Stock (%) | Difference |
|---|---|---|---|
| A (92+) | 14% | 1% | +13 pts |
| B (81-91) | 78% | 4% | +74 pts |
| C (69-80) | 7% | 29% | -22 pts |
| D or below (68-) | 1% | 66% | -65 pts |
The contrast is stark. Ninety-two percent of new builds in 2025 achieve a B rating or above, compared to just 5% of the existing housing stock. This performance gap has significant implications for property values, mortgage availability, and long-term running costs. As energy efficiency becomes increasingly embedded in property valuations, the premium commanded by high-EPC homes is expected to widen further.
Developer Readiness Assessment
With the full Future Homes Standard approaching implementation, the question of developer readiness has become a central concern for the industry. The transition requires changes across virtually every aspect of the housebuilding process, from design and procurement to site management and aftercare. Here is a comprehensive assessment of how the major housebuilders are positioned.
Readiness Scorecard: Key Metrics
| Metric | Industry Average | Top Quartile | FHS Target |
|---|---|---|---|
| Heat pump adoption rate | 52% | 78% | 100% |
| MCS-certified installers per 1,000 units | 3.2 | 6.8 | 8+ |
| FHS-compliant house types designed | 45% | 85% | 100% |
| Average air tightness achieved (m³/hr/m²) | 4.8 | 3.1 | ≤5.0 |
| Solar PV inclusion rate | 34% | 72% | Strongly recommended |
Supply Chain and Skills Challenges
The transition to higher energy standards is not solely a regulatory or design challenge; it is fundamentally a supply chain and workforce challenge. The heat pump market in the UK has grown rapidly, but from a relatively low base compared to European leaders like Sweden, Norway, and France. The Construction Industry Training Board (CITB) and MCS data highlight both progress and remaining gaps.
The installer gap is perhaps the most pressing concern. With approximately 8,200 MCS-certified heat pump installers in the UK as of early 2026, against an estimated need for 28,000 by 2028 to serve both the new build and retrofit markets, the shortfall is significant. The government's Heat Pump Investment Accelerator, which allocated £300 million to boost domestic manufacturing capacity, has helped with equipment supply, but the workforce bottleneck remains acute.
Material supply chains are also adapting. Triple-glazed window manufacturers have seen order books grow by 65% since 2023, while mechanical ventilation with heat recovery (MVHR) system suppliers report lead times of 8-12 weeks compared to 4-6 weeks for traditional extract ventilation. Insulation manufacturers are scaling production of higher-performance PIR and phenolic boards to meet the tighter fabric U-values demanded by both Part L 2021 and the forthcoming FHS.
What the Future Homes Standard Means for New Build Buyers
For prospective buyers, the FHS transition creates both opportunities and considerations. Homes built to the full standard will be significantly cheaper to run, more comfortable to live in, and better positioned to hold their value in an increasingly energy-conscious property market. However, the transition period itself requires careful navigation.
Expected FHS Home Performance
- Which building regulation standard is this home designed to — Part L 2021 or the full Future Homes Standard?
- What is the predicted SAP rating and EPC band?
- What type of heating system is installed (gas boiler, ASHP, GSHP, communal)?
- Is solar PV included as standard or available as an upgrade?
- What is the designed air tightness target?
- Is MVHR (mechanical ventilation with heat recovery) installed?
- What are the estimated annual running costs based on the SAP calculation?
- What warranties are provided for the heat pump and renewable systems?
Regional Variations in Energy Standard Adoption
The pace of transition is not uniform across the UK. Scotland, Wales, and England each operate under different building regulation frameworks, and even within England, regional variations in developer mix, housing type, and local planning policies create a complex patchwork of performance levels.
| Region/Nation | Avg EPC Score | HP Adoption | Key Policy Driver |
|---|---|---|---|
| Scotland | 90 | 68% | New Build Heat Standard 2024 |
| London | 89 | 62% | London Plan energy requirements |
| Wales | 87 | 55% | Part L Wales 2022 (similar to England) |
| South East England | 88 | 54% | Part L 2021 + local plan policies |
| East Midlands | 86 | 48% | Part L 2021 baseline |
| North West England | 85 | 44% | Part L 2021 baseline |
| Yorkshire & Humber | 85 | 42% | Part L 2021 baseline |
| North East England | 84 | 38% | Part L 2021 baseline |
Scotland leads the way, largely because the Scottish Government introduced its New Build Heat Standard in 2024, effectively banning direct-emission heating (i.e., gas boilers) in new homes a year ahead of the FHS in England. This has pushed Scottish housebuilders to adopt heat pumps faster, resulting in higher average EPC scores. London benefits from the London Plan's additional energy requirements, which require major developments to achieve net-zero carbon and connect to district heat networks where available.
The variation between English regions largely reflects the developer mix. Areas with a higher concentration of large-volume builders — who have adopted heat pumps more aggressively — tend to show higher adoption rates. Conversely, regions where SME builders play a larger role in housing delivery tend to lag, reflecting the capacity and cost challenges facing smaller firms.
The Role of Modern Methods of Construction
Modern Methods of Construction (MMC) — including timber frame, structural insulated panels (SIPs), modular construction, and hybrid systems — are increasingly interlinked with the energy standards transition. Factory-controlled construction environments allow for much tighter tolerances on insulation continuity, air tightness, and thermal bridge detailing, all of which are critical for FHS compliance.
Data from NHBC and the MPBA (Modular and Portable Building Association) indicates that homes built using MMC techniques achieve air tightness results approximately 40% better than traditionally built homes on average. This makes MMC a natural partner for the fabric-first approach demanded by the Future Homes Standard. Several major developers, including Barratt Redrow and L&G Modular, are expanding their use of factory-built components specifically to meet FHS targets more reliably.
Financial Incentives and Market Impacts
The energy transition is being supported by a growing array of financial incentives that collectively make higher-performing homes more attractive to both developers and buyers. These range from government grants and preferential mortgage products to local planning incentives and energy price differentials.
Key Financial Incentives
Challenges and Controversies
The transition is not without its detractors and challenges. Several significant issues continue to generate debate within the industry and among consumer groups.
The Performance Gap
One of the most persistent criticisms of new build energy performance is the so-called "performance gap" — the difference between designed (SAP-modelled) energy performance and actual in-use performance. Research by Leeds Beckett University and the Good Homes Alliance has consistently shown that many new build homes use 50-100% more energy than their SAP calculations predict, due to factors including construction quality variations, thermal bridging defects, and occupant behaviour.
The government has acknowledged this issue, and the FHS includes provisions for enhanced building control inspections, photographic evidence of insulation installation, and mandatory commissioning of heating systems. Some industry voices are calling for mandatory post-occupancy evaluation (POE) testing, where a sample of completed homes are monitored for 12 months to verify actual performance. While not yet required, several forward-thinking developers including Etopia Homes and Passivhaus-certified builders already undertake voluntary POE programmes.
The Affordability Question
Higher energy standards inevitably add cost to new homes. The Home Builders Federation estimates that full FHS compliance adds £5,000-£10,000 per dwelling depending on housing type and existing specification. Critics argue that in an already stretched housing market, adding further costs risks pricing out the very buyers who would benefit most from lower energy bills — particularly first-time buyers at the lower end of the market.
The counter-argument, supported by analysis from the Committee on Climate Change and the UK Green Building Council, is that the whole-life cost of an FHS-compliant home is lower than a home built to current Part L standards, once energy savings, maintenance costs, and potential carbon pricing are factored in. For first-time buyers, the key is that lower running costs improve mortgage affordability assessments, potentially allowing them to borrow more while spending less overall.
Consumer Understanding and Acceptance
Buyer awareness of heat pump technology and building performance standards remains patchy. HBF consumer surveys from 2025 indicate that while 72% of prospective new build buyers have heard of heat pumps, only 38% could correctly describe how they work, and 29% expressed concerns about reliability or noise. Education and positive word-of-mouth from early adopters are gradually addressing these perceptions, but the industry recognises that more needs to be done to build consumer confidence in the new technologies.
Frequently Asked Questions
Looking Ahead: The Road to Net Zero
The Future Homes Standard is a critical milestone, but it is not the final destination. The government's net zero 2050 commitment will require further evolution of building standards over the coming decades, including potential requirements for embodied carbon measurement, whole-life carbon assessments, and integration with smart grid technologies that allow homes to interact dynamically with the electricity network.
For the UK new build sector, the immediate priority is clear: deliver the FHS transition smoothly, close the skills and supply chain gaps, and ensure that the higher-performing homes being built actually deliver on their energy performance promises in practice. The industry has made remarkable progress over the past four years, but the next two will be the most challenging and consequential.
For buyers, the message is overwhelmingly positive. Whether you are purchasing a Part L 2021-compliant home today or waiting for a full FHS-specification property, new build homes offer dramatically better energy performance than the existing housing stock. The combination of lower running costs, better comfort, reduced environmental impact, and favourable financing terms makes the energy efficiency case for new builds stronger than it has ever been. For more on how these changes fit into the broader market picture, see our UK New Build Market Year in Review 2025.