New-Build & Regeneration Schemes: Solar panels for housing associations

Why new-build and regeneration schemes are the cheapest place to put social-housing solar

The most cost-effective rooftop solar a housing association will ever install is the array that was designed in from the start. On a new-build or regeneration scheme, PV integrates at design stage alongside the roof structure, the electrical provision and the heating strategy, so there is no retrofit scaffolding, no working around occupied homes and no surprise asbestos. The Future Homes Standard has made rooftop solar effectively standard on new social homes anyway, so for any registered provider building under the Affordable Homes Programme, the question is no longer whether to fit solar but how to integrate it well. Designed-in PV pairs naturally with air-source heat pumps and a fabric-first envelope to deliver homes that are genuinely low-cost to run for the tenant from day one. For a development team, that is a chance to build the running-cost performance in rather than retrofit it later at far greater expense, and to hand over a home that already performs rather than one that joins the retrofit backlog the moment it is occupied.

That matters because new social homes set the tenant's running cost for decades. A new dwelling built to the Future Homes Standard, with a heat pump and solar, can hand a resident an electrified home that is affordable to live in, rather than a low-carbon home that is expensive to heat. Solar is what makes an electrified, heat-pump-heated social home genuinely affordable to run, offsetting both the heat pump's running cost and the home's baseload. For an asset manager planning a regeneration scheme, integrating solar at RIBA design stage is the difference between a building that meets the standard on paper and one that actually keeps tenant bills and projected fuel poverty down across the whole scheme, and it avoids the situation where fabric and heat measures alone leave a home expensive to run.

What a typical install looks like and how we size it

For a designed-in social home we usually specify 2 to 4 kW, which is roughly 5 to 10 panels across about 12 to 24 square metres of roof. A system that size generates in the region of 1,700 to 3,600 kWh a year per home and saves somewhere between 0.4 and 0.8 tonnes of CO2 annually. Sizing on new build is cleaner than on retrofit because we design the roof loadings and electrical provision in from the start, so the array is not constrained by an existing roof structure or an awkward electrical layout. We size to the dwelling's expected daytime load, including the heat pump's running cost, so the household self-consumes most of the generation rather than exporting it cheaply. On regeneration blocks we size the communal array to the landlord supply and integrate it with the building's heat and electrical systems at design stage rather than bolting it on at handover, which keeps both the cost and the performance under control.

Costs, payback and tax relief

Designed-in PV typically runs £3,000 to £6,000 per home, materially cheaper than retrofit because the integration cost is absorbed into the build, with a simple payback near 8 years. On a block, designed-in arrays can cost roughly 40% less than an equivalent retrofit, because the access, structure and electrical provision are all part of the build rather than added afterwards. Surplus generation is registered under the Smart Export Guarantee at tariffs typically in the 4 to 15p/kWh range as of 2026, and on individual new homes the benefit model is set so the resident self-consumes the saving while the landlord or a tariff partner takes the surplus export. On communal arrays serving a block, the saving lands on the landlord supply and can be passed through to lower service charges. Our cost guide compares designed-in and retrofit economics so you can see the saving from integrating early and build it into the scheme appraisal.

The cost case for designing solar in rather than retrofitting it later is one of the clearest in the whole sector, and it changes how a development team should think about the measure. Retrofitting PV onto an occupied home means scaffolding, resident access, a separate mobilisation and the risk of an end-of-life or asbestos roof, all of which fall away when the array is part of the original build. The marginal cost of adding panels to a roof that is already being constructed, on a scaffold that is already up, with electrical provision that is already being run, is far lower than the cost of returning to do the same work years later. For a registered provider planning under the Affordable Homes Programme, that means the cheapest lifetime running cost for the tenant is locked in at the lowest capital cost at the design stage, and the appraisal should reflect the full lifetime saving rather than just the build-cost line. Building it in also avoids the awkward position of handing over a new social home that meets the Future Homes Standard on fabric and heat but is still more expensive to run than it needed to be because solar was left out.

Funding routes in detail

New-build and regeneration solar is funded differently from retrofit. The primary route is the Affordable Homes Programme, which grant-funds registered providers and local authorities building new affordable and social homes in England, with new homes built to the Future Homes Standard where rooftop solar is effectively standard. It is administered by Homes England, and by the Greater London Authority in London, and pairs naturally with heat pumps and fabric-first design. Per-home grant rates vary by tenure and region, so the funding is programme-level rather than a fixed per-home figure. The Smart Export Guarantee then provides ongoing export income on the completed scheme. Because new build is designed-in rather than retrofitted, the Warm Homes: Social Housing Fund, which targets existing EPC D-G stock, is generally not the relevant route here, the Affordable Homes Programme is, and we structure the solar element to fit the build's funding and procurement rather than treating it as a separate retrofit measure.

Compliance and sector considerations

New build follows a different compliance path from retrofit. The governing standards are the Future Homes Standard 2025 and Part L of the building regulations, with roof loadings and electrical provision designed in from the start. New build is typically out of scope for PAS 2035, which is a retrofit process applying to existing dwellings, but it still follows MCS certification and Part P and BS 7671 for the electrical work, and TrustMark registration where relevant. On regeneration blocks the building-safety regime under the Building Safety Act 2022 applies to higher-risk buildings of 18m or more, or seven storeys and above, and SPF1981 v3 fire design applies to rooftop arrays, which insurers expect on blocks. Grid connection is designed in: communal arrays above 3.68 kW per phase need a G99 application, which we lodge early in the design programme so the DNO timescale, which can run 6 to 18 months on constrained networks, does not hold up handover. Individual dwellings are usually a G98 connect-and-notify.

How we approach this kind of project

We get involved at design stage, ideally around RIBA Stage 3, so the roof loadings, electrical provision and grid connection are designed in rather than retrofitted. We size each dwelling to its expected daytime load including the heat pump, so the resident self-consumes and the home is cheap to run from day one, and on blocks we integrate the communal array with the building's heat and electrical systems. We submit the G99 grid application early, we coordinate with the main contractor and the heat-pump and fabric packages so solar is part of the whole-house design rather than a bolt-on, and we provide a fixed-price proposal with an insurance-backed warranty. Delivery runs through a compliant framework call-off so procurement stays clean under the Procurement Act 2023, and the benefit model is set before handover so residents know what they are getting and the scheme appraisal reflects the real running-cost performance.

Working as part of the design team rather than as a late-stage subcontractor is what makes the integration pay. Solar that is bolted on near completion tends to end up undersized, awkwardly routed or compromised by decisions taken earlier without it in mind, whereas solar designed in alongside the fabric and heat strategy can be optimised for the dwelling's real running profile. We model the whole-house package, fabric first, then electrified heat with an air-source heat pump, then solar PV to offset the heat pump's running cost and the home's baseload, because that is the order that delivers a genuinely affordable home for the tenant rather than a low-carbon one that is expensive to live in. Coordinating the grid connection early matters too: a communal array on a block needs a G99 application, and lodging it at the start of the programme means the DNO timescale runs in parallel with construction rather than threatening the handover date. The outcome is a scheme that performs at handover, not one that needs revisiting once residents move in, and a development that meets the Future Homes Standard in substance rather than just on the energy model.

An illustrative example

As an illustrative composite based on typical UK social-housing schemes: a registered provider delivering a 60-unit regeneration block of affordable and social-rent flats under the Affordable Homes Programme, built to the Future Homes Standard with air-source heat pumps and a fabric-first envelope, designed in a 150 kW rooftop array at RIBA Stage 3 serving the communal supply and landlord systems. Annual generation was around 138,000 kWh, offsetting heat-pump and communal load by roughly £26,000 a year, the designed-in PV cost about 40% less than an equivalent retrofit, and the block achieved high EPC ratings at handover with reduced projected tenant fuel poverty across the scheme. Combined with the heat pumps it delivered genuinely low-running-cost social homes from day one. The figures are illustrative and depend on the scheme, its systems and tariff.

For retrofit on existing stock alongside a new-build programme, see general needs housing solar and stock-wide decarbonisation programmes. When you are ready, read the cost guide, check the funding routes, request a free feasibility, or read the social-housing solar FAQs.