60+ office solar questions answered

UK office solar installed cost ranges £700-£1,200 per kWp depending on system size. A 100 kWp office system typically costs £90-100k; a 500 kWp HQ system £350-450k; a 1 MWp business park £700-950k.

5-7 years on cash purchase, 0 years on PPA (cash-flow positive day one). Depends on day-rate electricity cost, self-consumption ratio, and AIA eligibility.

Every 5p/kWh shift in day rate moves payback by roughly 0.5 years. Office customers paying 35p+/kWh see 4.5-year payback typical; those at 22p/kWh closer to 7.5 years.

£1.5m-£3m on a 300-500 kWp office install at 7% WACC. Roughly 5-7× capex outlay over 25 years discounted to present value.

12-18% over 25 years on cash purchase. Asset finance reduces by 2-3 percentage points due to interest cost. PPA delivers no IRR (no capex).

Yes. UK solar economics are now driven by grid retail electricity costs (currently 25-40p/kWh commercial) versus self-consumption avoided cost. Subsidies (FIT, ROCs) ended years ago; payback improved regardless.

Proposed UK regulation requiring EPC B minimum on commercial lets from April 2030 (tightening from current EPC E). Around 21% of UK office stock currently sub-B.

Directly no — MEES applies to landlords granting leases. Indirectly yes — owner-occupiers planning future sale or letting face the same threshold.

Solar adds 4-12 SAP/SBEM points depending on system size relative to floor area. For most C-rated offices above 2,000 sqm, solar PV lifts to EPC B comfortably.

Check the issue date and SAP version. EPCs from before 2022 used SAP 10.0 or earlier; SAP 10.2 (current) often re-rates pre-2022 Bs to C or D on renewal. Plan for re-rating risk.

10 years from issue. New EPC required for sale, letting, or major works. Plan re-rating in the 2026-2028 window for buildings facing 2030 deadline.

Yes. Civil penalties up to £150,000 per breach plus publication on the public PRS Exemptions Register. Trading Standards enforcement is currently moderate but expected to intensify post-2025.

Limited exemptions available (seven-year payback, all-cost-effective-measures, third-party consent, devaluation). Solar typically passes the seven-year payback test on most PV-feasible offices — meaning you can't exempt out of installing PV.

In most cases no. Commercial solar up to 50 kWp on non-listed, non-Conservation-Area buildings is Permitted Development under Class A Part 14 of the GPDO. Above 50 kWp requires Prior Approval (56-day notice).

A 56-day notice process administered by your Local Planning Authority for solar installations above 50 kWp. Simpler than full planning. LPA can object only on amenity, design, or transport grounds.

56 days statutory. If LPA doesn't determine in time, deemed approval applies. We typically see determination within 4-8 weeks.

Permitted Development rights restricted on principal elevations facing public highway. Other roof areas typically retain PD. Full planning permission needed where PD doesn't apply.

Yes, with Listed Building Consent. Approval rates around 78% in our experience for well-designed proposals, lower (40-55%) on Grade I and Grade II*. Concealed rear-roof placement helps.

Standard Permitted Development restrictions apply with additional sensitivity to landscape impact. Pre-application discussions with the planning authority strongly recommended.

8-13 weeks typical. Heritage settings sometimes longer. We manage the application end-to-end as part of fixed-price proposal.

For Monday-Friday offices, target 70-80% of annual kWh consumption. We size from half-hourly meter data, not square-metre rules of thumb.

Typical UK office: 100-2,000 panels. A 5,000 sqm office consuming 1.2 GWh/year needs around 880 kWp = 1,955 panels (at 450W each).

5.5 panels per square metre of usable roof. After exclusions for plant, walkways, and edge zones, expect 60-78% of gross roof area to be usable.

Modern UK office flat roofs typically rated for 30+ kg/sqm dead load. Ballasted solar typically 15-20 kg/sqm. Structural engineer signs off as part of design.

Yes. Pitched-roof installs use clip-fix or rail-and-bracket mounting. South-facing pitches deliver highest yield; east-west pitches typically 80-85% of south.

PVSyst yield modelling accounts for specific shading from named adjacent structures. Significant shading (>2 hours/day in summer on >20% of array) materially reduces economics.

On-site: 2-10 weeks depending on system size. Total project programme: 6-9 months from feasibility to commissioning.

Generally minimal. Most cabling and mounting work on roof. Switchgear modifications scheduled for out-of-hours where required. Weekend or night work available at premium.

Yes. Under GHG Protocol Scope 2 Guidance, on-site solar credits in both location-based and market-based methods. Every kWh self-consumed reduces reported Scope 2 by the grid emissions factor (~0.21 kg CO₂e/kWh currently UK).

On commissioning: location-based and market-based Scope 2 calculations, SECR-ready narrative, CDP response text, TCFD mapping, SBTi alignment statement, PPN 06/21 CRP input data.

Significantly. Most UK office occupiers can't hit 2030 SBTi targets without renewable electricity coverage — and on-site solar is typically the cheapest single contribution to that coverage.

No, for on-site self-consumption. Physical traceability is sufficient. REGOs become relevant for SEG registration and specific corporate procurement standards.

Solar features in both the Energy Efficiency Actions section (qualifying action) and Emissions section (Scope 2 reduction). We provide ready-to-use narrative text.

Solar features across all four TCFD pillars: Governance (board-level capex), Strategy (transition opportunity), Risk Management (price hedge + MEES regulatory risk), Metrics (Scope 2 reduction).

Cash purchase delivers highest NPV. Asset finance the next-best, cash-flow positive month one. Operating lease for off-balance-sheet. PPA for zero capex.

AIA gives 100% first-year tax deduction up to £1m. For limited companies at 25% corp tax, that's £250k of tax saving on a £1m install — 25% effective cost reduction in year one.

Salix PSDS applies to government, NHS, local authority, FE colleges, and state schools. Up to 100% capex grant. Phase 4 funding rounds open annually.

OZEV grant providing £350/socket up to 40 sockets (£14,000 max) for EV chargers at workplaces with off-street parking. Any UK business eligible.

Smart Export Guarantee pays 5-12p/kWh for electricity exported to grid. All UK PV systems up to 5 MWp eligible. Best tariffs from Octopus (Outgoing Agile ~10-13p) and E.ON Next Export Exclusive (~10p).

IETF for industrial-context offices (R&D HQs, factory-attached offices) — up to 30% capex max £6m. UKIB for portfolio rollouts >£5m total — below-market debt finance.

Standard 20% VAT on commercial solar. Recoverable through normal VAT registration. Some PPA structures qualify for zero-rating but always seek tax advice.

Yes, with landlord consent via green-lease addendum. Three routes work: tenant-funded with consent, landlord-funded with service-charge recovery, third-party PPA.

Through service charge for electricity supplying landlord-controlled areas (lifts, plant, common parts). Must comply with RICS Code 2018. Direct tenant supply needs sleeve PPA or sub-meter arrangement.

PPA where landlord (or third party) supplies electricity directly to tenants via building MPAN structure. Captures full economic value but needs tenant agreement and sometimes Class Exemption Order.

Tenant-installed solar typically has make-good obligations. Green-lease addenda often waive make-good in exchange for landlord receiving system at lease end.

Generally yes — solar improves EPC, lowers opex, lifts asset value. Open-market rent reviews capture some of this; indexed reviews don't. Lease "disregards" clauses can exclude tenant improvements.

Sale price typically captures some of the PV value uplift. EPC uplift and MEES compliance significantly improve marketability. PPA structures need novation or buy-out.

Above 200 kWp solar + 800 MWh annual consumption, typically yes. Below that, usually NPV-negative. Specific economics depend on day rate, DUoS region, and load shape.

0.4-0.7× daily peak summer generation. A 280 kWp office would typically pair with 200-300 kWh battery rated for 100-150 kW discharge.

Lithium iron phosphate (LFP) dominates commercial in 2026. 6,000-10,000 cycle warranty, 90-93% round-trip efficiency, better thermal stability than NMC.

OZEV grant providing £350/socket up to 40 sockets (£14,000 max) for EV chargers at workplaces. Any UK business with off-street parking eligible.

Yes. Daytime EV charging absorbs midweek solar generation. Typically lifts office self-consumption 8-15 percentage points, dropping payback by 1-1.5 years.

When rooftop area is constrained or branded visibility matters, and surface parking has 40+ spaces. Premium £300-£500/kWp vs rooftop. Often combined with EV charging.

Free, no obligation. We need 12 months half-hourly meter data and a roof plan. Turnaround 7 working days. Output: full system spec, generation, savings, payback, NPV, EPC uplift, all four finance routes, planning route, applicable grants.

You decide whether to proceed. If yes: 2-4 weeks design phase, 8-13 weeks planning/DNO, 8-12 weeks procurement + install. Total programme typically 6-9 months.

No. Feasibility, planning route assessment, DNO consultation, grant mapping, and finance modelling are all free of charge.

Nothing. Feasibility study is yours to keep. No obligation, no pressure.

Fixed-price design-and-build contract under JCT or NEC Short Form. Stage payments aligned to milestones (design, materials, mobilisation, commissioning).

Our MCS-certified, NICEIC-approved engineering teams. No subcontracted "white-labelled" installs.