What the on-site survey covers
The on-site survey is the second stage of our six-stage project pathway, after the free desk feasibility. It establishes the technical detail needed to quote confidently — roof structure, electrical supply, fabric condition, and heritage sensitivity. The survey is free and carries no commitment to proceed.
Structural assessment
Our structural engineer assesses:
- Roof structure — rafter size, span, condition, materials
- Existing dead load — current weight of slate, tile, lead, plaster
- Spare load capacity — typically 10-25% headroom for solar panels
- Wind exposure — uplift and shear loading from local wind atlas
- Fixings options — non-penetrative clamps, in-roof flush, ballasted (for flat roofs)
- Access routes — scaffold positioning, crane access, panel staging
For listed buildings the structural engineer also reviews the last quinquennial report and engages with the diocesan architect.
Electrical assessment
Our electrical engineer assesses:
- Incoming supply — single-phase or three-phase, main switch rating, supply head condition
- Existing distribution — consumer unit / distribution board condition, capacity for solar inverter
- Earthing arrangement — TN-C-S, TN-S, TT, suitability for solar
- DNO connection requirements — G98 (sub-13 kW single-phase) or G99 (larger or three-phase)
- Cable routing — DC cables from roof to inverter, AC cables from inverter to distribution
- Inverter location — typically vestry, boiler room, or external weatherproof enclosure
Heritage assessment (listed buildings)
For Grade II, II* and I listed buildings, our heritage specialist (typically an EASA-aligned architect) assesses:
- Visual impact from key viewpoints — typically lych gate, principal churchyard approach, wider settlement views
- Fabric sensitivity — which fabric is most heritage-significant; which fabric is more recent and less sensitive
- Slope selection options — chancel south vs nave south vs vestry vs outbuildings
- Reversibility — fixing methods that can be undone without permanent fabric damage
- Conservation officer engagement — informal pre-application conversation with the diocesan architect and local heritage officer
What we provide afterward
Within 14 working days of the on-site survey, we deliver:
- Fixed-price proposal — no variation orders without your written approval
- Detailed drawings showing panel layout and fixings
- System specification with panel and inverter selection
- Conservation rationale (for listed buildings) supporting the design choices
- Indicative grant strategy with named funding routes specific to your parish
- Project timeline from PCC vote to commissioning
- Ongoing monitoring and maintenance plan
Common survey questions
How long does the on-site survey take?
Typically half a day to a full day depending on building complexity. For Grade I and Grade II* buildings we usually take longer (sometimes a second visit) because of the additional heritage assessment. For simple modern halls, a half-day is standard.
Who attends the on-site survey?
Structural engineer (assesses roof and fixings), electrical engineer (assesses supply and DNO requirements), heritage specialist (for listed buildings). For Grade I/II* projects we also invite the diocesan architect to attend so their concerns shape the design from the outset.
What does the survey produce?
A detailed fixed-price proposal within 14 working days. Includes drawings, fixings specification, conservation rationale, system specification, indicative grant strategy, and project timeline. Forms the basis of the formal PCC decision to proceed.
Is the survey free?
Yes — the on-site survey is included in our standard process at no charge. There is no commitment to proceed after the survey. We do this because the survey gives us the information we need to quote confidently and gives the PCC the information they need to decide.
What if you find problems we did not expect?
Honest communication. If the survey reveals problems (e.g. roof deterioration that requires repair before any install, electrical supply that cannot support the planned system, heritage fabric that needs different design) we explain the implications and propose options.