Why building type matters
The technical envelope of a commercial PV installation is set by the building it sits on. Structural capacity, roof material warranty, roof access route, electrical infrastructure layout, planning category, and tenant occupancy model all flow from the building type. A 300 kWp install on a 2010 flat-roof multi-let is a fundamentally different project from a 95 kWp install on a Grade II* listed Georgian townhouse — even if both are office buildings of broadly similar floor area.
This page maps six dominant UK office typologies to the design and consent considerations that drive each. Click through to the dedicated page for full detail.
The six dominant typologies
~62% of UK office stock
Flat-roof offices
The dominant UK office typology. Ballasted east-west mounting standard. 15-20 kg/sqm loading typical, well within most post-1990s structural capacity.
Read more →~4% of UK office stock
Listed office buildings
Listed Building Consent required regardless of size. Concealed rear-roof + ballasted = 78% approval rate. Heritage Impact Assessment essential.
Read more →~15% of UK office stock
Glass curtain wall offices
Post-1990s Grade A. Rooftop PV primary route; BIPV in curtain wall for new-build or refurb only. Solar carports often add useful capacity.
Read more →~6% of UK office stock
Atrium office buildings
Solid PV ring around atrium opening; never on atrium glazing itself (defeats daylight intent). Semi-transparent BIPV niche option.
Read more →~3% of UK office stock
Lightweight solar for modular buildings
Modular & prefabricated roofs carry just 8-15 kg/m². Lightweight ballasted or direct frame-fix at 8-12 kg/m², fully relocatable. Specialist installer & supplier, London & UK-wide.
Read more →~40% of UK office buildings have multi-let leases
Multi-tenant office buildings
Service-charge cost recovery, sleeve PPA, or green-lease addendum routes. RICS Code 2018 compliance essential.
Read more →Roof can't take the weight? Lightweight solar
A recurring constraint across building types is roof load capacity. Older buildings designed to lighter codes, profiled metal-deck roofs, large-span structures, and modular buildings all share the same problem — a conventional ballasted array at 18-25 kg/m² is simply too heavy. The answer is lightweight solar panels for commercial buildings, engineered to install at 6-12 kg/m², and for modular and prefabricated buildings specifically, our lightweight solar for modular buildings service. Both are available as installer, supplier, or both, across London and the UK.
Cross-cutting considerations
Regardless of building type, four design considerations recur across every commercial office PV project:
- Structural capacity per BS EN 1991-1-1 (dead loads) and BS EN 1991-1-4 (wind loads). We assess at first site visit; reinforcement requirements identified at proposal stage.
- Roof membrane warranty preservation — typically requires ballasted (penetration-free) mounting plus original manufacturer sign-off.
- Electrical infrastructure — switchgear age, available capacity, cable route to the array, G99 grid connection at the DNO.
- Planning route — Permitted Development under Class A Part 14 GPDO 2015, Prior Approval above 50 kWp, full planning or Listed Building Consent for heritage settings.
Where to start
If you know your building's primary typology, click through to the dedicated page above. If you're unsure (some buildings span multiple categories — e.g. a multi-tenant glass curtain wall office), the fastest answer is via a free desk feasibility study. Send us your half-hourly meter data and a roof plan, and we'll confirm the technical route + economic outcome within 7 working days.