What Makes a Commercial Building a Good Solar Prospect? The 5-Factor Scoring Model
The biggest inefficiency in commercial solar sales in Ireland isn't closing — it's wasted site visits. Experienced installers know the feeling: you drive 40 minutes, walk the roof, and know within five minutes it's not viable. Small usable area, north-facing slopes, HVAC units clustered across every flat section. The visit was a waste of time for both parties, and you'll do it again next week unless something changes.
The solution is scoring buildings before you visit — using data that already exists. Tailte Éireann has floor area records for every commercial property in Ireland. PVGIS holds irradiance data at per-kilometre resolution. Satellite imagery covers every address. The question is whether you're working from that data or from a list of addresses and gut feel. Here are the five factors that determine whether a commercial building is a genuine solar opportunity.
Why buildings fail solar viability
Most commercial buildings that look viable from the road fail on one of five grounds. The question isn't whether a building has a roof — every building has a roof. The question is whether that roof can generate a commercially viable return over a realistic payback period. A building can fail on roof area, on irradiance, on obstruction density, or on ownership structure — and any one of those is enough to make a site visit pointless.
The five factors: Usable roof area · Solar irradiance · Roof obstruction score · Building ownership · Lead tier classification
Threshold: Minimum ~100m² usable area for a viable commercial system (approximately 15kWp). Optimal is 500m²+ (75kWp+).
What kills it: Pitched roofs where only south-facing slopes count toward usable area. Irregular shapes with narrow sections. Roof areas below 50m² after obstruction mapping.
Ireland note: Tailte Éireann records commercial floor area in m². VantageHQ uses this as a ground-truth proxy for roof potential before satellite analysis is applied.
Threshold: ≥900 kWh/m²/year global horizontal irradiance. Ireland ranges from ~950 kWh/m²/year on the south coast (Cork, Wexford, Waterford) to ~870 kWh/m²/year in the northwest (Donegal, Leitrim).
In practice: A building on the south coast of Cork will generate roughly 8–12% more energy than an identical building in Donegal. The biggest factor remains roof area and orientation — not geography.
What it checks: HVAC units, parapets, skylights, lift shafts, and roof terraces. Each obstruction is mapped and usable panel area is estimated.
Confidence score: VantageHQ assigns a confidence rating (High / Medium / Low) based on satellite image clarity and obstruction complexity. Low-confidence buildings are flagged for physical verification before prospecting.
What kills it: Industrial buildings with dense HVAC clusters can lose 40–60% of usable roof area. Older flat-roof buildings in city centres often perform better than modern industrial units with complex plant rooms.
The challenge: Many commercial buildings are owned by holding companies, investment funds, or landlords — not the occupier. Prospecting the tenant without the landlord's approval is a dead end.
What VantageHQ does: CRO records are used to identify the registered company at each address, the directors, and whether the structure is owner-occupier or tenant. Buildings where ownership is unclear are flagged.
Why it matters: A Gold-tier building with a perfect roof but a passive landlord scores lower than a smaller owner-occupied building. Ownership structure affects close probability more than most installers account for.
Factor 5: Lead Tier Classification
This is the output — not an input. Once factors 1–4 are scored, each building is classified into one of three tiers. The tier determines prospecting priority and shapes the conversation before you've made a single call.
Gold: ≥500m² usable area, ≥950 kWh/m²/year irradiance, High AI confidence, owner-occupier. Approximately 15% of ICP buildings in Ireland fall into this tier.
Silver: Meets 3 of 4 Gold criteria. Approximately 35% of ICP buildings. Strong opportunity with one qualification to work through — often ownership structure or a marginally smaller roof.
Bronze: Viable with one material qualification — typically a roof just above the viability threshold or medium AI confidence pending verification. Approximately 50% of ICP buildings.
All 12,400+ Gold and Silver buildings across Ireland are in the VantageHQ dataset, indexed by county, sector, and decision-maker.
Why this matters for your conversion rate
The math is straightforward. If an installer visits 20 unscored buildings per month and closes 3 — a 15% visit-to-close rate that most commercial solar teams would consider normal — versus visiting 20 pre-scored Gold-tier buildings and closing 6 or 7, the revenue difference compounds significantly over a year. The visit-to-close rate is the critical metric most installers never measure, because they don't have a baseline to measure it against.
Pre-scored prospecting doesn't just improve close rates. It changes the nature of site visits. When you arrive already knowing the roof area, the irradiance, the obstruction profile, and who owns the building, the site visit becomes a validation exercise rather than a qualification exercise. That changes the dynamic of the conversation from the first minute.
The buildings worth ignoring
Standard-tier buildings — low irradiance, small roof, or tenant-occupied without a cooperative landlord — exist in every county. Longford has 980 commercial buildings, but only 140 meet the solar ICP threshold when scored on all five factors. The other 840 are buildings — but they are not solar prospects. Galway has over 4,200 commercial properties, of which roughly 1,100 score as Gold or Silver. Knowing which 3,100 to skip is as commercially valuable as knowing which 1,100 to call.
The discipline of pre-scoring is partly about finding the right buildings — but it's equally about protecting the time you'd otherwise spend on the wrong ones. Every wasted site visit is a missed call on a Gold-tier building somewhere else.
How the scoring works in practice
VantageHQ runs the five-factor model across every commercial building in Ireland with a rated capacity above the viability threshold. The output is a scored, tiered dataset indexed by county and sector. When you log in for a county — Tipperary, Cork South, Kildare — you see the Gold and Silver buildings first, with roof area, irradiance, obstruction confidence, and CRO-linked decision-maker data attached.
The data to score every commercial building in Ireland already exists. Tailte Éireann has the floor areas. PVGIS has the irradiance. Satellite imagery exists for every address. The CRO has the ownership structure. The question is whether you're working from that data, or from a spreadsheet of addresses and a lot of unnecessary driving.
See the Gold and Silver leads in your county
Every county in Ireland, scored and tiered. Filter by sector, tier, and roof size — then start prospecting the buildings worth your time.
Browse county leads →