Future Homes Standard: What Cornwall Self-Builders & Developers Need to Know
By Thomas Lea, Certified Passivhaus Designer and OCDEA Energy Assessor
The Future Homes Standard is changing how new homes are designed, heated and powered in England. For property developers, landowners and self-builders in Cornwall, understanding the new requirements is essential to planning a successful residential development.
However, national Building Regulations are only part of the picture. Cornwall Council's SEC1 Sustainable Energy and Construction policy sets additional energy-performance targets for applicable residential developments, creating further considerations for local projects.
At CAD Architects, we combine architectural design with in-house Passivhaus design expertise and SAP assessment capabilities, as part of our Carbon services, helping our clients, developers and our CAD Planning division, to navigate these requirements from the earliest stages of all residential projects.
When Does the Future Homes Standard Come Into Force?
The Future Homes Standard was published on 24 March 2026, with the new requirements scheduled to come into force in 2027.
Key dates include:
- 24 March 2027: New requirements come into force for most relevant building work.
- 24 September 2027: Separate commencement arrangements apply to higher-risk buildings.
- 24 March 2028: Principal transitional deadline for eligible non-higher-risk projects.
Transitional arrangements are subject to specific conditions relating to building control submissions and commencement of work.
Considering the requirements early can help identify potential design changes and cost implications before a project progresses too far.
What Are The Main Future Homes Standard Requirements?
The Future Homes Standard updates the Building Regulations, including Part L (energy efficiency and greenhouse gas emissions) and Part F (ventilation). Its objective is to deliver zero-carbon-ready homes designed for a lower-carbon energy system.
The main areas affecting all new residential development include:
Low-carbon heating: The standard is designed around low-carbon heating, such as air source heat pumps or suitable heat networks. Gas boilers will generally struggle to meet the new performance requirements compared with heat-pump-based designs.
Renewable electricity: New dwellings must meet the national requirement for on-site renewable electricity generation. Solar photovoltaic (PV) panels are expected to be an important solution, subject to the prescribed calculation methodology and applicable conditions.
Building fabric: Insulation, glazing, airtightness and thermal-bridge detailing all contribute to energy performance. The proposed dwelling must satisfy the applicable energy-performance targets; notional reference values should not be mistaken for universal minimum specifications.
Ventilation and overheating: The design must address ventilation and, where applicable, overheating requirements. These considerations need to be coordinated with airtightness, window design and solar gain.
The challenge for self-builders and developers is bringing these elements together in a coherent architectural and technical design. That is where we can assist.
Future Homes Standard vs Cornwall SEC1 Policy
Cornwall Council's Policy SEC1 – Sustainable Energy and Construction, within its Climate Emergency Development Plan Document, has applied to relevant planning decisions since June 2023.
SEC1 establishes local energy-demand and renewable-generation objectives for applicable residential developments. The Future Homes Standard does not automatically replace these planning requirements.
How do the requirements compare?
| Design consideration | Future Homes Standard | Cornwall SEC1 |
| Building fabric | Assessed through the national energy-performance methodology, including the Target Fabric Energy Efficiency Rate (TFEE). | Fabric performance must support the policy's space heating and energy-demand targets. |
| Space-heating demand | No equivalent fixed space-heating demand cap. Fabric performance is assessed through TFEE alongside the other compliance metrics. | Less than 30 kWh/m²/year. |
| Total energy use | Assessed against the applicable Target Primary Energy Rate (TPER) and Target Emission Rate (TER). | Less than 40 kWh/m²/year, using SEC1's calculation conventions. |
| Heating systems | The notional dwelling uses a heat pump. The more demanding emissions target (TER) makes heat-pump-based designs a more straightforward route to compliance than gas heating in many cases. | No single heating technology is prescribed, but the heating strategy must support the energy-demand targets. |
| Solar PV and renewables | On-site renewable electricity is required. The national guidance includes a reference PV output based on panels rated at 0.22 kWp/m² over an area equivalent to 40% of the dwellinghouse's ground-floor area, subject to the prescribed conditions and alternative compliance route. | On-site renewable generation should match the dwelling's total annual energy demand, with solar PV the preferred solution. |
| Airtightness and ventilation | The SAP 10.3 notional dwelling assumes air permeability of 4 m³/(h·m²) at 50 Pa. The separate limiting value is 8 m³/(h·m²) at 50 Pa. | Important considerations in achieving the space heating and energy targets and demonstrating compliance. |
| Compliance evidence | Building Regulations calculations and supporting documentation under the approved methodology. | An Energy Statement and relevant energy calculations and supporting evidence for applicable proposals. |
The two frameworks use different assessment methods. Meeting one does not automatically demonstrate compliance with the other.
The Three Performance Targets
The Future Homes Standard assesses a proposed dwelling against three calculated national performance targets. These are based on a notional dwelling with the same size and shape as the proposed home, but with standardised fabric and building-services assumptions.
- Target Emission Rate (TER): Measures the permitted level of modelled emissions. The more demanding emissions target favours low-carbon heating, making an air source heat pump a more straightforward compliance route than a gas boiler in many designs.
- Target Primary Energy Rate (TPER): Measures modelled primary energy use, including the energy associated with supplying electricity and other fuels. The slightly relaxed target takes into account low-carbon heating assumptions and the additional electricity consumption of heat pumps.
- Target Fabric Energy Efficiency Rate (TFEE): Measures the useful energy demand associated with space heating and cooling, focusing on the building fabric rather than the efficiency of the heating system itself. The notional dwelling's fabric assumptions establish the target for the individual design.
A comparison of the previous Part L notional dwelling vs the FHS notional dwelling
| Notional dwelling element | Part L 2021 | Future Homes Standard 2026 (SAP 10.3) |
|---|---|---|
| External walls | 0.18 W/m²K | 0.18 W/m²K |
| Floors | 0.13 W/m²K | 0.13 W/m²K |
| Roofs | 0.11 W/m²K | 0.11 W/m²K |
| Windows and glazed doors | 1.2 W/m²K | 1.2 W/m²K |
| Opaque doors | 1.0 W/m²K | 1.0 W/m²K |
| Airtightness | 5 m³/(h·m²) at 50 Pa | 4 m³/(h·m²) at 50 Pa |
| Notional heating system | Gas boiler | Air source heat pump (SCOP 2.5) |
| Ventilation | Natural ventilation with intermittent extract fans | Decentralised mechanical extract ventilation (dMEV) |
| Solar PV | Included in the notional dwelling calculation as a reference system | Assessed separately as per on-site renewable electricity requirement |
The calculated performance of the actual dwelling is expressed through the corresponding dwelling metrics: DER, DPER and the dwelling fabric energy efficiency rate. The actual dwelling must satisfy the applicable targets under the approved calculation methodology.
SAP / Home Energy Model (HEM)
The government intends the Home Energy Model (HEM) to replace the Standard Assessment Procedure (SAP), but its introduction has been delayed.
As of October 2026, SAP 10.3 remains the approved methodology for demonstrating compliance with the Future Homes Standard. The future implementation timetable should be confirmed against the latest government guidance.
Our in-house SAP assessment capabilities allow us to consider energy performance alongside architectural design and the relevant Building Regulations requirements. SEC1 has its own assessment requirements, so the appropriate calculations and supporting evidence must be considered separately for each framework.
We will be continuing to develop our skills, and actively training with HEM, to ensure a smooth transition for all clients.
How Passivhaus Design Can Support Energy Performance
Although Passivhaus certification is not a requirement of the Future Homes Standard or Cornwall Council’s SEC1 policy, applying Passivhaus principles can help bring many residential designs closer to the required energy-performance targets.
By prioritising a high-performance building fabric, excellent airtightness, reduced thermal bridging and carefully designed ventilation, Passivhaus-informed design aims to reduce energy demand while improving comfort and building performance.
Our in-house Passivhaus designer brings this expertise into the architectural design process, helping us consider energy performance alongside the form, materials and construction of a proposed building.
The outcome depends on the building design, energy assessment, heating system and renewable-energy provision. Passivhaus principles alone do not guarantee compliance with either framework.
How We Can Help With Your Development
Navigating the Future Homes Standard and SEC1 involves more than understanding the regulations. It requires informed decisions about architectural design, energy performance, heating, ventilation, renewable technology and the planning context.
We bring together architectural design, in-house Passivhaus design expertise and SAP assessment capabilities to help clients understand the implications for their proposed schemes and develop an appropriate design approach.
Whether you are assessing a development site, planning a new-build home or exploring a residential conversion, we can help you consider the requirements from the outset.
Planning a new-build or residential development in Cornwall?
Contact us to discuss your project and how the Future Homes Standard, SEC1 policy and energy-performance requirements may affect your plans.
Email: studio@cadarchitects.co.uk
Phone: 01872 630040
Further Information
- GOV.UK – Approved Document L (2026)
- GOV.UK – Future Homes and Buildings Standards: Building Circular 01/2026
- GOV.UK – Standard Assessment Procedure
- Cornwall Council – Planning Policy Guidance, including SEC1
Requirements and transitional arrangements will be confirmed to our clients for each project.
