Most working farms above 400 acres have multiple buildings suitable for solar PV. The right approach isn't to install on every building at once — it's to plan a 2-4 year capital programme that prioritises the buildings with the best payback, manages cash flow, and coordinates G99 grid connection across the programme. Here's how we plan multi-building rollouts for UK farms in 2026.
Why phasing usually wins over a single big install
Single-shot installation on all buildings: maximum upfront capex (£600k-£1.5m+ for a 6-8 building programme); single G99 application but maximum DNO exposure if rural feeder is capacity-constrained; single mobilisation efficiency; all buildings commissioned simultaneously.
Phased installation over 2-4 years: capital deployed in tranches matching trading profit and AIA availability; G99 applications staged with DNO capacity becoming available; learning from Phase 1 informs Phase 2 design; tax-efficient timing across multiple AIA years; lower single-decision risk.
For most multi-building UK farms, phasing wins on three counts: (1) AIA tax efficiency — installing £400k of capex in two years rather than one captures 100% AIA against profit in each year rather than constraining; (2) DNO capacity management — staged G99 applications increase the chance of getting full export capacity vs trying to land 800 kW+ in one application on a constrained feeder; (3) cash flow predictability — installing in tranches matched to operational cash flow vs single large capital outlay.
Building prioritisation framework
We rank every building on the holding by three factors:
**Simple payback.** Buildings with high daytime baseload, suitable roof, and PV-ready cladding pay back fastest. Typically dairy parlour first; livestock houses second; grain stores or poultry sheds third; equestrian/workshop last.
**Self-consumption ratio.** Buildings with continuous 24/7 baseload (dairy parlour, intensive poultry) achieve 85-95% self-consumption. Seasonal-load buildings (arable grain stores) achieve 35-55%. We model SC% per building and weight accordingly.
**Install complexity.** Asbestos cement cladding requires combined re-roof + PV — significantly longer programme, higher upfront cost. We typically install on direct-PV-ready buildings first and combined re-roof + PV second.
The resulting priority order for a typical UK mixed farm: (1) dairy parlour, (2) main livestock shed with PV-ready cladding, (3) grain store, (4) main workshop, (5) older livestock buildings requiring combined re-roof + PV.
Phase 1 design considerations
Phase 1 should: deliver the strongest immediate payback (typically the dairy parlour or main livestock shed); validate our approach with the farm operator (single-building install lets you see exactly how we work before committing to Phase 2); generate Year 1 operational data that informs Phase 2 sizing.
Typical Phase 1: 100-300 kW on one or two buildings. Capex £85k-£260k. Delivery 4-6 months from contract.
Phase 2 design considerations
Phase 2 should: extend coverage to the next priority buildings; consume any Phase 1 learnings (final inverter selection, integration patterns, on-site protocols); leverage Phase 1's G99 connection (Phase 2 typically connects under the existing G99 with capacity increase, not new application).
Typical Phase 2: 200-500 kW on 2-3 additional buildings. Capex £160k-£425k. Delivery 5-7 months from Phase 2 contract.
Phase 3 design considerations
Phase 3 typically addresses the remaining buildings, often including combined re-roof + PV on older asbestos cement buildings. Phase 3 can also include battery storage and EV charging infrastructure that complements the now-mature multi-building generation profile.
Typical Phase 3: combined re-roof + PV on older buildings + 100-200 kWh battery + EV charging. Capex £200k-£500k.
G99 grid connection programming
For multi-building programmes, we typically submit a single G99 application with phased capacity (e.g., 150 kW Phase 1, additional 200 kW Phase 2, additional 300 kW Phase 3). This is more efficient than three separate G99 applications. The DNO commits to the total programme capacity upfront; Phase 2 and Phase 3 are commissioned under the existing G99 without new study requirements.
On capacity-constrained networks, programmed phasing can be the difference between getting any solar at all and getting none — the DNO may not accept a single large application but will accept a phased programme with capacity headroom for network reinforcement work in between phases.
Financing across phases
Multiple financing approaches work for multi-building programmes. Most common patterns:
**All capital (highest-cash-flow farms):** Phase 1 + Phase 2 + Phase 3 paid from operating cash. AIA claimed in each install year. Tax efficiency optimised; balance sheet exposure highest.
**Mixed capital + finance:** Phase 1 cash + AIA; Phase 2 asset finance over 7 years; Phase 3 cash + AIA. Spreads cash flow exposure.
**Phase 1 asset finance, Phase 2-3 capital:** Phase 1 funded by lender; Phase 2-3 funded by Phase 1's operational savings flowing into capital reserves. Capital-light start.
We model financing scenarios per phase as part of the desk feasibility.
Why this approach makes sense
For most multi-building UK farms in 2026, the phased programme delivers: faster Year 1 cash flow positive position (Phase 1 generating before Phase 2 capex hits); better DNO outcomes on capacity-constrained networks; AIA tax optimisation across multiple years; lower single-decision risk; ability to incorporate learnings between phases (final design tweaks, contractor relationships, operational integration).
The alternative — single large install — works for farms with strong cash flow, simple DNO position, and no constraints. For most other farms, phasing wins.
How to start your multi-building programme
Send us a brief on your farm — total acreage, building count, building types, electricity spend, any planned modernisation programmes (re-roofing, electrical upgrade, new building construction). We deliver a free multi-building feasibility study within 14 working days, including building-by-building prioritisation, total programme size, phased delivery roadmap, total capital requirement across phases, and indicative 25-year financial model showing how the programme cashflows.