After years of consultation and delay, the government has published the final Approved Documents for the Future Homes Standard. Every new home in England will need low-carbon heating, mandatory solar panels, and dramatically improved energy performance. The regulations come into force on 24 March 2027, with a 12-month transitional period for projects already in the pipeline. Here is what the published documents confirm, what has changed, and what it means for each part of the industry.
Approved Documents L and F Published in Final Form
Sources: GOV.UK Building Circular 01/2026, GOV.UK Consultation Response, Elmhurst Energy ·
MHCLG has published the final statutory instruments and approved documents that make up the Future Homes and Buildings Standards. The package includes new editions of Approved Document L (conservation of fuel and power) Volumes 1 and 2 and Approved Document F (ventilation) Volume 1, alongside the government's formal response to the 2023 consultation and full impact assessments.
The regulations come into force on 24 March 2027, exactly 12 months from publication. Higher-risk building work has a later start date of 24 September 2027 for certain provisions. The government has also published Building Circular 01/2026 setting out the detailed amendments.
This is the culmination of a process that began with the 2019 Future Homes Standard consultation and has been through multiple iterations, including the 2021 Part L uplift and the 2023 consultation on the full standard.
What this means
The speculation is over. Housebuilders, designers, and the supply chain now have confirmed requirements and a firm implementation date. The 12-month lead time is shorter than some in the industry had hoped for, but longer than the 6 months that was rumoured. The publication also confirms that the standard originally targeted for 2025 will finally land in 2027. For a complete breakdown of compliance routes, see our compliance pathways guide.
Key Requirements Confirmed
Solar PV Becomes a Legal Requirement for New Homes
Source: GOV.UK ·
A new functional requirement L3 creates a legal obligation for on-site renewable electricity generation on all new dwellings. In practice, this means rooftop solar PV panels equivalent to 40% of the dwelling's ground-floor area. Exemptions apply for buildings over 18 metres in height, higher-risk buildings, and sites where a minimum output of 720 kWh per year cannot be achieved (for example due to heavy shading or complex roof geometry).
What this means
This is a genuine first for English building regulations: a standalone legal requirement for renewable generation, not just an assumption in the notional building. The 40% rule will push most detached and semi-detached homes towards 3-4 kWp systems. For HEM's solar PV modelling, self-consumption and battery storage become even more important in demonstrating compliance.
Low-Carbon Heating Mandatory: Gas Boilers Cannot Comply
Source: Construction News ·
The standard requires new homes to achieve a 75% reduction in carbon emissions compared to homes built under 2013 regulations, alongside mandatory low-carbon heating. Gas boilers cannot meet these targets. The government estimates FHS-compliant homes will save households up to £830 per year on energy bills compared to a standard EPC C-rated property. Heat pumps (air source and ground source) and connection to heat networks are the expected solutions.
What this means
This is the effective end of gas boilers in new homes. Every compliance calculation will now run through heat pump performance modelling, making SAP 10.3 and HEM the gatekeepers for what gets built. The supply chain pressure is real: the industry needs to scale from around 100,000 heat pump installations a year to several times that.
Transitional Arrangements and Sunsetting Confirmed
Source: GOV.UK ·
Projects with a building notice, initial notice, or full plans application submitted before 24 March 2027 can build to current Part L 2021 standards, provided work commences before 24 March 2028. Critically, the government has also revoked earlier transitional provisions from 2013 and 2021 that still allowed construction to 2010 energy standards. Any plots relying on those older provisions must now meet the Future Homes Standard if not commenced.
What this means
The sunsetting is significant. Some large development sites were still building to 2010 standards under legacy transitional arrangements. That route is now closed. For developers with uncommenced plots, the clock has started. See our transitional arrangements guide for the full picture.
Ventilation Commissioning Rules Tightened
Source: Elmhurst Energy ·
Updated Approved Document F requires that all new ventilation systems are commissioned by a member of a competent person scheme. Powered flow hoods are now mandatory for ventilation commissioning, with rotating vane anemometers prohibited. The Building Safety Regulator is reviewing competent person schemes to ensure adequate quality. These changes apply alongside the tighter airtightness standards that make mechanical ventilation essential in most FHS homes.
What this means
Poorly commissioned ventilation has been a persistent problem in airtight new builds. Banning vane anemometers and requiring competent person schemes is a direct response. For builders, this means investing in powered flow hoods and ensuring installers are registered. For assessors, ventilation testing at completion becomes more rigorous.
SAP 10.3 Confirmed as Sole Methodology at Launch
Source: Elmhurst Energy ·
As previously signalled, SAP 10.3 will be the only approved compliance methodology when the FHS goes live in March 2027. The government describes this as ensuring a "fully approved and supported solution available from day one." The Home Energy Model will follow a minimum of three months after the FHS launch, once it receives approved methodology status. A dual running period will then allow both SAP 10.3 and HEM before HEM eventually replaces SAP entirely.
The Approved Document L 2026 retains the three performance metrics from Part L 2021: primary energy rate (DPER), carbon emissions (DER), and fabric energy efficiency (DFEE). Elmhurst Energy notes it is already developing "Design: HEM" software in anticipation of HEM becoming an approved route.
What this means
The pattern from the earlier announcement holds: SAP 10.3 first, HEM second. For assessors and software vendors, the immediate task is SAP 10.3 readiness. But the direction of travel is clear: HEM is the long-term methodology. Firms that invest in understanding HEM now will be better positioned when dual running begins. The retention of three metrics (rather than simplification) also means compliance calculations remain detailed and multi-dimensional.
Key Dates at a Glance
| Date | Milestone |
|---|---|
| 24 March 2026 | Approved Documents and regulations published |
| 24 March 2027 | FHS comes into force (most building work) |
| 24 March 2027 | Deadline to submit applications under current Part L 2021 |
| Mid-2027 (earliest) | HEM becomes approved methodology (3+ months after FHS) |
| 24 September 2027 | FHS in force for higher-risk building work |
| 24 March 2028 | Deadline to commence transitional projects under Part L 2021 |
| H2 2027 | Reformed EPCs expected (separate workstream) |
Fabric Performance and Airtightness
The published documents confirm two compliance options for the notional dwelling. Both deliver the same overall carbon reduction target but with different balances of airtightness, ventilation strategy, and renewable generation:
| Specification | Option 1 (MVHR) | Option 2 (Natural Vent) |
|---|---|---|
| Airtightness | 4 m³/m²/hr @ 50 Pa | 5 m³/m²/hr @ 50 Pa |
| Ventilation | dMEV (decentralised mechanical extract) | Natural ventilation |
| Drain water heat recovery | Required (WWHRS) | Not required |
| Solar PV | Required (Part L3) | Required (Part L3) |
| Low-carbon heating | Required | Required |
The tighter airtightness targets represent a step change from typical current practice. Most new builds today achieve 4-6 m³/m²/hr, so the MVHR route is broadly achievable but demands consistent build quality. For detailed guidance on how HEM models these requirements, see our guides to fabric heat loss, ventilation modelling, and Part L changes.
Industry Reaction
The National Federation of Roofing Contractors welcomed mandatory solar but warned of "significant gaps" in installer competence and fire safety testing. Ben Rowlands, the NFRC's head of solar PV, cautioned that the more solar goes into the built environment, the more critical proper safety frameworks become.
Deepika Singhal of Hollis consultancy emphasised that the 12-month transitional period "should not be used as an excuse for delay," arguing that firms should begin preparing immediately.
The construction cost impact is estimated at 3-8% per dwelling, offset by significantly lower running costs for occupants. The government's impact assessment projects that the new standards are cost-effective over the lifetime of a building, with FHS homes being described as "zero carbon ready": they will not require retrofit to achieve net zero once the electricity grid is fully decarbonised.
What to Watch Next
- Coming months: updated SAP 10.3 software from BRE-approved vendors; expect a wave of product launches and training as the industry prepares
- Mid-2027: HEM approved methodology status; the start of dual running with SAP 10.3
- H2 2027: reformed EPCs for existing homes (separate from FHS)
- Part O review: the government has signalled a full technical review of the overheating standard using updated CIBSE TM59 criteria
- Material change of use: standards for conversions are not changing yet; further consultation is expected
We will be updating our Future Homes Standard guide, timeline, and all audience-specific pages with the confirmed details over the coming days.
Frequently Asked Questions
When does the Future Homes Standard come into force?
24 March 2027 for most building work. Higher-risk buildings have a later date of 24 September 2027 for certain provisions. Projects with applications submitted before March 2027 can build to current standards if commenced before March 2028.
How much solar PV is required under the Future Homes Standard?
New dwellings must install solar PV equivalent to 40% of the ground-floor area. Exemptions apply for buildings over 18 metres tall, sites where 720 kWh/year output cannot be achieved, and higher-risk buildings. This is a new functional requirement under Part L3.
Are gas boilers banned under the Future Homes Standard?
Not banned by name, but effectively yes. The standard requires low-carbon heating and a 75% carbon reduction compared to 2013 standards. Gas boilers cannot meet this, so heat pumps and heat networks become the default for new homes from March 2027.
Will compliance use SAP 10.3 or the Home Energy Model?
SAP 10.3 only at launch. HEM will follow a minimum of three months later, after which a dual running period begins. HEM eventually becomes the sole methodology.
Does the Future Homes Standard apply to existing homes?
No. The FHS applies to new dwellings only. Existing homes are covered separately. The government has retained current standards for conversions and will consult further. EPC reform for existing homes is a separate workstream expected in late 2027.
Related Pages
Future Homes Standard: Complete Guide
Everything you need to know about the FHS, from fabric standards to compliance routes.
Timeline & Status
Live tracker of HEM, FHS, EPC reform, and MEES milestones.
Part L Changes Under the FHS
Detailed breakdown of the new Part L requirements, fabric specs, and heating standards.
SAP 10.3 vs HEM: Which to Use?
Compare the two compliance methodologies and understand which applies when.
Transitional Arrangements
Deadlines, commencement rules, and strategies for managing the transition.