A logistics operator with forty depots, a REIT with a mixed retail and industrial portfolio, or a local authority with schools and offices — all face the same problem. Solar is strategically attractive, but capital and management attention are finite. Portfolio solar feasibility screening is how you decide which roofs deserve serious analysis and which should wait.
This is not the same as a full feasibility study on every building. Screening is the funnel; feasibility is the confirmation stage on winners.
Why portfolios need a different approach
Single-site feasibility assumes you already care about one address. Portfolio owners care about ranking: which sites deliver the best payback per pound spent, which clear net-zero contributions, and which carry unacceptable grid or lease risk.
Without screening, teams either spread budget thinly across too many full studies or advance the loudest internal advocate’s building without evidence. Neither scales.
Stage1Energy supports both ends: free screening for rapid filtering and fixed-fee site assessments at £1,250 per site for board-ready dossiers on shortlisted sites.
Stage one: eligibility filters
Before any technical analysis, apply hard gates that do not need a solar specialist.
Ownership and lease term. Is the landlord willing? Does the lease run long enough for payback? Short leaseholds without renewal path stop most projects.
Roof access rights. Can you install and maintain equipment? Rights of access and alienation clauses matter.
Roof area and type. Very small or heavily plant-filled roofs may fail on area alone. Fragile or temporary structures are poor candidates.
Strategic fit. Is the building retained in the portfolio? Planned disposal or major redevelopment may pause solar spend.
Consumption plausibility. Empty buildings, storage-only units with minimal load, or all-export models need honest marking as marginal.
Sites failing eligibility should not receive feasibility budget yet. Fix the lease or strategy first.
Stage two: coarse technical and economic triage
Remaining sites get a lighter technical pass — often remote, using aerial imagery and benchmarks.
Estimate usable roof area and estimated kWp range. Flag obvious shading, multiple small roofs, or heritage constraints. Place sites in coarse bands: strong, marginal, or weak on self-consumption fit based on tenant type and opening hours.
Warehouse with high daytime load? Strong. Cold store with efficient baseload? Strong. Sublet office with unknown tenant consumption? Marginal until data arrives.
This stage maps well to free screening: a verdict in three working days per site without committing to a full dossier on the whole portfolio.
Stage three: full feasibility on the shortlist
Advance typically five to fifteen percent of a large portfolio to full feasibility in the first wave — more if the portfolio is homogeneous (e.g. identical distribution centres).
Full dossiers provide comparable NPV, payback, flags, and verdicts so investment committees can rank apples with apples. See what is in a solar feasibility report for the standard section set.
Homogeneous portfolios benefit from batch ordering: consistent methodology, parallel delivery, and unified assumptions on tariff and capex benchmarks. Heterogeneous portfolios may need segmented assumptions by building type.
Sequencing spend across financial years
Portfolio screening aligns with capital planning cycles. Year one might screen the full estate and feasibility the top ten. Year two feasibility the next tranche while year-one sites move to survey and install.
Avoid the trap of feasibility on sites with no install budget for three years unless the dossier informs imminent roof works or lease negotiations. When to order a solar feasibility study applies at portfolio scale too.
Data management at portfolio scale
Spreadsheets defeat most portfolio programmes. Maintain a master register: site ID, roof area, screening band, feasibility status, verdict, flags, and next action.
Minimum viable fields for screening:
- Address and asset manager
- Roof type and approximate m²
- Lease expiry and landlord consent status
- Tenant sector and load indicator
- Screening verdict and date
- Feasibility ordered Y/N and outcome
When half-hourly data exists for subset sites, attach it before full feasibility — the financial section strengthens materially.
Common portfolio pitfalls
Treating all roofs as equal. Identical-looking sheds can differ on grid headroom, load, and lease.
Letting installers pick the sequence. They optimise for installability and margin, not portfolio IRR ranking.
Skipping screening because feasibility is “only £1,250”. Multiply by two hundred sites and the waste is obvious.
Ignoring grid clusters. Multiple buildings on one substation may compete for export capacity — portfolio screening should note electrical geography, not just individual roofs.
Forgetting roof works programmes. A site mid-refurbishment may jump the queue once the deck is renewed.
Board and investor narrative
Portfolio screening produces a story, not just a list: “We assessed 120 assets, screened out 45 on lease or area, advanced 18 to feasibility, and recommend 6 for capital approval this year.”
That narrative supports solar investment board papers better than a single-site dossier alone. Pair portfolio summary slides with full PDFs for the funded sites.
Working with Stage1Energy on large portfolios
There is no hard ceiling on how many roofs we can programme. Estates of dozens to 80+ sites are welcome — including logistics networks, REIT holdings, and local-authority stocks. Scope, sequencing, and pricing are agreed in writing before work starts; calendar pacing is about delivery timeline, not a size refusal.
A practical pattern for large programmes: free screening across a wide list for triage, then fixed-fee site assessments on the shortlist at £1,250 per site, with a cross-portfolio ranking for the board. Enquire about programme pricing via the portfolio programme.
Working with Stage1Energy on portfolios
Start with commercial solar feasibility overview, then submit priority sites for free screening. Advance positives to fixed-fee dossiers via site assessment.
Review example report structure with your team so everyone knows what arrives from the queue. For market context affecting portfolio timing, see commercial solar feasibility in 2026.
Screening turns a sprawling estate into an ordered pipeline — the step most portfolios skip and later regret.
Governance and reporting rhythm
Establish a quarterly review of the portfolio register with asset management, sustainability, and finance present. Screening bands should update when leases change, tenants turn over, or roof works complete. A site marked marginal in January may jump to strong in June once half-hourly data arrives from a new metering programme.
Document who can authorise feasibility spend on shortlisted sites — typically estates leadership within a pre-agreed annual envelope. That prevents ad-hoc one-off dossiers that bypass portfolio ranking and keeps pricing predictable for finance planning across the year.