The Future Homes Standard and Solar: What UK Architects Need to Know

For new dwellings in England, solar is about to stop being a design choice. From 24 March 2027 the Future Homes Standard introduces a new functional requirement, L3, for on-site renewable electricity generation on new dwellings and buildings containing dwellings. It was published on 24 March 2026, so there is a year to get ahead of it, and a transitional arrangement that rewards projects already in the system. Everything else below sits on top of that: the tax position, the compliance route and the client-side arguments. We have written it for architects working in London and the South East, and we have left out the incentives that no longer exist.

1. Grants and funding: what actually exists

No general grant for new-build solar. It is worth saying plainly, because clients ask. The Renewable Heat Incentive is still widely cited and it is gone: the non-domestic scheme closed to new applicants in March 2021 and the domestic scheme in March 2022. It would not have helped anyway, because it was a heat scheme and never covered solar PV. The real financial case for solar on a new dwelling is the capital allowances and VAT position below, plus the fact that from March 2027 you will be specifying it regardless.

Local Authority Grants: Some London boroughs and combined authorities run their own retrofit and renewable funding, but the schemes open and close on their own timetable and most are aimed at existing homes rather than new build. Treat any borough scheme as something to check at the time rather than something to design around, and check it for the specific address.

Salix Funding: Public sector decarbonisation funding is administered by Salix and runs in rounds rather than continuously, so what is open changes from year to year. If you are working on a school, a hospital or another public building, the question to ask early is which round the project can realistically be timed against, because the funding window usually drives the programme rather than the other way round.

2. Tax Incentives

Capital allowances on commercial projects. Enhanced Capital Allowances were abolished in April 2020, so ignore any source that still mentions them. Solar PV is special rate plant and machinery, which has two consequences worth knowing before a client's accountant tells you. Full expensing does not apply to special rate assets, so the headline 100% first-year relief you may have read about is not available for panels. A 50% first-year allowance for companies is, and it is now permanent. For most projects the more useful route is the Annual Investment Allowance, which gives 100% relief on qualifying expenditure up to its annual limit and therefore covers a typical commercial array outright.

VAT, and the deadline inside it. It is not a reduced rate, it is zero. The installation of solar PV in residential accommodation in Great Britain is zero-rated for VAT until 31 March 2027, after which it reverts to the reduced rate of 5% rather than to 20%. Battery storage has been zero-rated in its own right since 1 February 2024, including batteries retrofitted to an existing system. The date is the point for a design team: a residential project that completes after March 2027 carries 5% on the solar element where one completing before it carries none. This is general information rather than tax advice, and the client's accountant should confirm the position for the specific contract.

3. What changes on 24 March 2027

The Future Homes Standard, and requirement L3. The Building Regulations etc. (Amendment) (England) Regulations 2026 were made in March 2026 and come into force on 24 March 2027, with a later date of 24 September 2027 for higher-risk building work. They create a new functional requirement, L3, covering the provision of on-site renewable electricity generation for new dwellings and buildings containing dwellings, and they come alongside the 2026 edition of Approved Document L. The practical shift is that generation stops being one of several ways to hit a target and becomes a requirement in its own right, so the roof has to be planned for it rather than accommodate it late.

The transitional arrangement, and why it matters now. For work other than higher-risk buildings, the new requirements do not apply where a building notice, an initial notice or an application for building control approval with full plans was given before 24 March 2027, provided the work on that building starts before 24 March 2028. That gives roughly a year of protection for schemes already in the system and a hard stop for everything else. Two things follow for a practice with a residential pipeline. Schemes you want to keep under the current standard need their notice in before March 2027. Everything after it should be drawn with generation on the roof from the first sketch, because retrofitting the decision at technical design is where it gets expensive. Approved Document L Volume 1 carries the sizing guidance, and we are happy to run the numbers against a specific roof layout at concept stage.

4. Professional Recognition and Career Advancement

Accreditations and Awards: Green building accreditations like BREEAM and LEED place high importance on renewable energy sources. Designs featuring solar panels can more easily achieve these certifications, enhancing the project's and the architect's prestige.

Innovation Awards: Architects who frequently incorporate cutting-edge renewable technologies may find themselves in the running for various industry awards, boosting their professional reputation and leading to more business opportunities.

5. Client Demand and Market Differentiation

Eco-conscious Consumers: While not the stereotypical "saving the planet" narrative, there's a rising demand from eco-aware clients who are seeking sustainable living solutions. Architects who position themselves to meet this demand can carve out a niche market.

Corporate Social Responsibility (CSR): For commercial clients, integrating solar panels aligns with broader CSR goals. Architects who offer solutions that can contribute to a company’s CSR objectives can foster stronger client relationships and repeat business.

6. Educational and Institutional Adoption

Funding for schools, and what has closed. Be careful here, because the picture has changed and the older guidance still circulating is wrong. The Public Sector Decarbonisation Scheme closed its Phase 4 application window, and the Great British Energy solar programme for schools selects the schools it works with rather than inviting applications, with its stated targeting outside London. For a London school the realistic routes are the trust's or local authority's own capital, a power purchase arrangement, or whatever Salix round is open at the time. Check what is actually live before it goes in a feasibility report.

Research and Development Tax Credits: Worth understanding mainly so it is not over-promised. The merged R&D scheme applies to accounting periods beginning on or after 1 April 2024, and it relieves qualifying research and development, not the purchase and installation of established technology. Specifying standard panels on a building does not qualify. Genuine development work, such as a novel integrated facade product, might, and that is a conversation for the client's tax adviser rather than something to write into a design report.

The short version: the grants mostly are not there, the tax position is better than most sources claim and has a deadline in it, and from March 2027 on-site generation on new dwellings is a requirement rather than an option. Nothing here is tax or legal advice, and the client's accountant and the building control body should confirm the position on any specific scheme. If you would like a second pair of eyes on roof layout, array sizing, DNO capacity or how the connection works on a particular site, we survey and install across London and are happy to look at a scheme at concept stage, when the decisions are still cheap to make.