Building
- BMS
- Centralised control platform managing HVAC, lighting, security, and increasingly solar PV monitoring. Modern BMS integrations enable solar generation data to drive cooling pre-cooling strategies and EV charging schedules.
- BREEAM
- UK sustainability rating system for commercial buildings. Solar PV contributes Energy (Ene) and Pollution (Pol) credits toward BREEAM Outstanding/Excellent/Very Good ratings.
Compliance
- CDM 2015
- UK health and safety law applying to all commercial construction projects including solar installs. Triggers Principal Designer and Principal Contractor duties on projects above 30 person-days or 500 person-hours.
- EICR
- Mandatory periodic inspection of fixed electrical installations to BS 7671. Required every 5 years for commercial premises. Solar PV install triggers updated EICR scope.
- EPC
- UK statutory rating of building energy efficiency from A (best) to G (worst). Required for sale, letting, or major works on commercial buildings. Solar PV adds 4-12 SAP/SBEM points typically.
- ESOS
- UK statutory scheme requiring large undertakings (>250 employees or >£44m turnover) to conduct quadrennial energy audits. Phase 4 reporting deadline December 2027.
- IWA
- Third-party insurance protecting against installer business failure. If the installer goes bust, the IWA insurer honours the workmanship warranty. Standard 10-year IWA in commercial solar via QANW or GPI.
- MCS
- UK quality scheme for renewable energy installations. MCS Commercial certification is mandatory for SEG eligibility and signals installer competence. Always require MCS Commercial-certified installer for office projects.
- MEES
- UK regulations barring landlords from letting commercial property below specified EPC ratings. Currently EPC E minimum; planned EPC C from April 2027 and EPC B from April 2030. The dominant single driver of UK office solar adoption.
- SAP / SBEM
- Standard Assessment Procedure (residential) and Simplified Building Energy Model (commercial). The calculation methodologies underlying EPC ratings. SAP 10.2 (2022) introduced significant changes affecting commercial PV credit.
- SECR
- UK mandatory reporting framework for quoted companies and large unquoted companies. Annual disclosure of energy use, Scope 1+2 emissions, intensity ratio, and energy efficiency actions. Office solar qualifies for both action and reduction reporting.
ESG
- CDP
- Global voluntary disclosure framework for corporate climate, water, and forest impacts. Near-universal among FTSE-100. Office solar features in CDP sections C6 (emissions), C8 (energy), and C9 (additional metrics).
- CRP
- Document mandatory under PPN 06/21 for bidders on UK government contracts >£5m per year. Must include baseline emissions, current emissions, and commitment to net zero by 2050. Office solar features in the "Environmental Management Measures" section.
- ESG
- Investment and corporate reporting framework covering non-financial performance. Office solar is the single most material Scope 2 emissions reduction available to most UK occupiers — central to ESG performance.
- GHG Protocol
- Global standard for corporate emissions accounting. Categorises emissions into Scope 1 (direct), Scope 2 (purchased energy), Scope 3 (value chain). Office solar reduces Scope 2.
- GRESB
- Real estate sustainability benchmark widely used by institutional investors. Office portfolios benchmark on Scope 2 emissions, energy intensity, and renewable energy percentage — all directly improved by solar PV.
- REGO
- UK certificate system tracking renewable electricity generation. On-site solar generation can be REGO-certified but typically isn't — physical traceability is sufficient for Scope 2 market-based reporting on self-consumed kWh.
- SBTi
- Global voluntary corporate net zero pathway certification. SBTi-validated targets typically require -42% absolute Scope 1+2 by 2030. Office solar is essential to most UK SBTi commitments.
- TCFD
- Global framework for climate-related financial disclosure. Mandatory for UK premium-listed companies. Office solar features across Governance, Strategy, Risk, and Metrics pillars.
Finance
- AIA
- UK tax relief providing 100% first-year deduction on qualifying plant and machinery up to £1m per business per year, permanently set at £1m from April 2023. The most material capital allowance for office solar — a £288k install delivers £72k of year-one tax saving at 25% corporation tax.
- CapEx
- One-time investment in long-term assets like solar PV systems. Qualifies for AIA, Full Expensing, and depreciation. Contrasts with OpEx (PPA, lease payments).
- Full Expensing
- UK tax relief providing 100% first-year deduction (main pool) or 50% (special-rate pool) for limited companies on qualifying plant and machinery. Solar PV falls into special-rate pool. Permanent from 2024.
- IFRS 16
- Accounting standard putting most lease arrangements on balance sheet from 2019. Affects choice between asset finance, operating lease, and PPA for office solar projects.
- IRR
- Annualised return on capex over project life. UK office solar typically delivers 12-18% IRR over 25 years on cash purchase. Drops to 0% (not negative) on PPA where no capex is committed.
- LCOE
- Per-kWh cost of solar generation across system lifetime, accounting for capex, opex, financing, and degradation. UK office solar LCOE typically 5-9p/kWh in 2026 — well below grid retail.
- NPV
- Discounted-cash-flow value of future returns minus upfront capex, using a discount rate (typically 7-10% WACC for UK commercial). The standard board-level financial metric for office solar capex decisions.
- PPA
- Contract where a third party installs and owns the solar system, selling electricity to the customer at a discounted per-kWh rate over 15-25 years. Zero capex, cash-flow positive day one, lowest 25-year NPV of finance routes.
- Sleeve PPA
- Power purchase agreement where the landlord (or third party) supplies electricity directly to one or more tenants through the building's metering. Common in multi-let office solar where direct tenant supply maximises economic capture vs landlord-areas-only service charge recovery.
- UKIB
- UK national investment bank providing below-market debt for clean infrastructure projects >£5m. Useful for office portfolio rollouts and large business park installs.
- WACC
- Blended cost of equity and debt capital used as the discount rate in NPV calculations. UK commercial WACC typically 7-10%. Office solar NPV at WACC is the standard board financial test.
Government
- DESNZ
- UK government department responsible for energy policy and net zero strategy. Successor to BEIS for energy matters since February 2023.
- HCD
- Document required for Salix PSDS applications setting out the building or estate's pathway from fossil heating to electric. Solar PV is typically combined with heat pump retrofit in PSDS-funded projects.
- IETF
- UK grant scheme providing up to 30% capex (max £6m) for industrial decarbonisation projects in England. Office-based businesses qualify where the office is part of an industrial site.
- OZEV
- UK government office administering EV incentive schemes including the Workplace Charging Scheme (WCS), which provides £350/socket grant for office EV chargers.
- PPN 06/21
- UK Procurement Policy Note requiring bidders for government contracts >£5m per year to publish a Carbon Reduction Plan. Office solar features in the Environmental Management Measures section.
- PSDS
- Salix-administered UK grant scheme providing up to 100% capex grant for public-sector office solar combined with heat decarbonisation. Phase 4 funding rounds open annually.
- WCS
- OZEV grant scheme providing £350/socket up to 40 sockets (£14,000 max) for businesses installing EV chargers at workplaces with off-street parking.
Grid
- DNO
- Regional electricity grid operator (UKPN, Western Power, Northern Powergrid, ENW, SPEN, SSEN). Manages the local network and approves new solar PV connections via G98 or G99 application.
- DSR
- Grid services revenue scheme paying flexible electricity users to shift or reduce demand during peak periods. Battery storage paired with office solar can participate via aggregators like Limejump, Flexitricity, or Octopus Energy.
- DUoS
- Component of UK commercial electricity bills covering DNO network costs. Varies by time of day with "red band" peak (4-7pm weekdays in winter) at £0.20-£0.40/kWh. Battery storage discharge during red-band displaces high-cost grid import.
- G98
- Engineering Recommendation governing connection of micro-generation (≤3.68 kW single-phase or ≤11 kW three-phase). Below the threshold for typical office solar installations — G99 applies instead.
- G99
- Engineering Recommendation governing connection of solar PV systems above 50 kWp single-phase or 16A per phase three-phase. The standard grid connection application for office solar. Typical DNO determination 8-18 weeks; constrained networks longer.
- MPAN
- Unique identifier for an electricity supply point. Multi-let office buildings typically have multiple MPANs for landlord-controlled areas and individual tenants. Sleeve PPA arrangements operate via specific MPAN structures.
- Net Metering
- Billing arrangement where solar generation is netted against consumption on the same MPAN. UK does not have full net metering — instead the Smart Export Guarantee pays a separate per-kWh tariff for exported electricity.
- SEG
- UK mandatory tariff scheme paying solar PV generators for electricity exported to grid. Current tariffs 5-12p/kWh depending on supplier. MCS-certified system and SMETS2 smart meter required.
- SMETS2
- Second-generation Smart Meter Technical Specification. Required for SEG eligibility on solar PV installations. Half-hourly export metering capability is mandatory.
- TRIAD
- Historical UK transmission charging system where peak winter demand drove half of total transmission cost. Abolished from April 2023; replaced by capacity-band pricing. Battery storage strategies that "avoided TRIAD" have shifted to red-band DUoS shifting.
- TUSL
- Historical predecessor name for what became TRIAD charges. Now obsolete under reformed Targeted Charging Review (TCR) regime.
Industry
- BCO
- UK trade body for the commercial office sector. Publishes Best Practice guidance on office specification, fit-out, and sustainability — increasingly influential on MEES 2030 capex strategy.
Planning
- AONB
- UK protected landscape designation with planning restrictions on visible-elevation solar installations. Permitted Development rights restricted on principal elevations facing public highway.
- Article 4 Direction
- Local Planning Authority order removing Permitted Development rights in a specific area, typically Conservation Areas. Where in force, even small office solar installations require full planning permission rather than PD or Prior Approval.
- Class A Part 14
- The specific Permitted Development class in the Town and Country Planning (General Permitted Development) Order 2015 that grants automatic permission for commercial solar PV up to 50 kWp on non-listed buildings outside Conservation Areas.
- GPDO
- Statutory instrument granting blanket planning permission for specific development types. Class A Part 14 covers commercial solar up to 50 kWp.
- PD
- Planning permission granted by default for specific development types under the GPDO 2015. Commercial solar up to 50 kWp on non-listed, non-Conservation-Area buildings is PD.
- Prior Approval
- Planning notice process for commercial solar above 50 kWp on non-listed buildings. 56-day determination period. LPA can object only on specific grounds (amenity, design, transport). 92% approval rate in our experience.
Property
- Green Lease
- Commercial lease addendum covering sustainability obligations between landlord and tenant — typically including data sharing on energy use, agreed minimum efficiency standards, and provisions for installing PV/EV/heat pumps. Better Buildings Partnership publishes a standard toolkit.
- RICS Code 2018
- RICS Professional Statement on Service Charges in Commercial Property 2018. Governs how landlords can recover capex (including solar) via service charge on multi-let buildings. Three principles: transparency, reasonable, communicated.
Service
- O&M
- Ongoing service covering monitoring, inspection, cleaning, and reactive maintenance of solar PV systems. Typically £8-25 per kWp per year depending on tier. Often bundled into the first 5 years of capex.
Technical
- DC-to-AC Ratio
- Ratio of solar panel DC nameplate capacity to inverter AC capacity. Optimal range for UK office installations is typically 115-125% — see the "120% rule" blog post. Captures more yield in normal conditions at the cost of minor clipping at peak irradiance.
- Inverter
- Power electronics device converting solar panel DC output to AC for grid use. Major UK-market brands: Solis, Huawei, Sungrow, Fronius, SMA. Typical 10-year warranty, 20-25 year operational life on commercial models.
- kWp
- Solar PV system capacity measured at Standard Test Conditions (1000 W/sqm irradiance, 25°C cell, AM1.5 spectrum). 1 kWp = roughly 1,850 panels of 540W each. UK office systems typically 50-1000 kWp.
- LFP
- Battery chemistry dominant in commercial-scale storage in 2026. Higher cycle life (6,000-10,000), better thermal stability, lower fire risk than NMC chemistry. Round-trip efficiency 90-93%.
- PV
- Solar electricity-generating technology (as distinct from solar thermal). All office solar PV systems in the UK use crystalline silicon PV panels.
- PVSyst
- Industry-standard solar yield modelling software. Accounts for latitude, longitude, panel orientation, shading, inverter clipping, temperature derating, and 25-year degradation. Real-world generation typically lands within 2-4% of PVSyst projection.
- Self-consumption Ratio
- Fraction of solar generation used on-site (vs exported to grid). UK office buildings typically achieve 70-85% without battery, rising to 90-95% with battery. The single biggest economic lever in commercial solar.
- String Inverter
- Inverter type connecting multiple panel strings into a single AC output. Standard for commercial office solar at sizes 50-300 kWp. Typically located in plant rooms or switchrooms.
Technology
- BIPV
- Solar PV technology integrated into the building fabric (façade, glass, roof tiles, curtain walls) rather than mounted on top. Premium cost (£2,500-£4,000/kWp installed) typically only justified on architecturally sensitive office buildings.