Comparison guide

ASHP vs GSHP

Survey scope differences in the UK, with the practical evidence installers need before quoting and design.

This isn’t a “which is better” sales pitch. It’s a practical checklist of what typically changes in survey scope so you can plan evidence capture and reduce follow‑ups.

ASHP survey reports Get pricing

Delivery: report + organised photos are available in the portal immediately upon completion of the visit. EPC delivered by next morning. If a calculation is needed, it is delivered the next day.

Scope

What typically changes in the survey

Exact requirements depend on scope and installer process — we confirm what you need before booking.

ASHP

Common ASHP focus areas

External unit siting constraints (space, routing, access)
Internal plant area context
Evidence to reduce design assumptions

GSHP

Common GSHP focus areas

Ground loop / trench / bore feasibility context
Site constraints that impact routing and civils
Evidence to support groundworks planning (where in scope)

Both

The constant: a clear report

Photos grouped by decision (not timestamps)
Assumptions made explicit
A clear report that cuts callbacks

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Evidence detail

ASHP vs GSHP survey evidence: what the office needs to know

Both survey types need a reliable property record, but the risk points are different. A useful survey separates what was measured on site, what was supplied by the installer or customer, and what still needs design review.

ASHP siting

Outdoor unit position and sound context

Air source heat pump survey evidence normally needs outdoor unit position options, boundary context, nearby openings, access for installation and maintenance, cable or pipe route notes, and the inputs needed for MCS 020(a) sound checks where they are in scope.

GSHP groundworks

Ground loop, borehole or trench feasibility context

Ground source heat pump surveys need more attention on available land, access for machinery, likely disruption, manifold or plant location, ground constraints, and whether the installer needs extra design or ground investigation before quoting hardens.

Shared evidence

Plant, emitters and measured rooms

Both routes benefit from room measurements, emitter notes, cylinder and plant context, electrical intake evidence, loft or fabric observations where relevant, and labelled photos that help the designer understand the job without chasing a second visit.

Choose the route

Which Vertex page should an installer use?

Use the broad heat pump page when the technology or evidence route is not fixed. Use the ASHP or GSHP pages once the system type is known.

Broad comparison

Heat pump survey company

Best when the installer is comparing survey partners, wants ASHP and GSHP coverage, or needs heat loss, EPC, electrical and plant evidence handled through one report route.

Confirmed air source

ASHP survey

Best when the job is already an air source heat pump and the key questions are outdoor unit siting, MCS 020(a) inputs, access, electrics, heat loss and report handover.

Confirmed ground source

Ground source heat pump survey

Best when the job needs GSHP-specific notes around plant space, land, trench or borehole feasibility, access, constraints and the wider handover for design review.

Check UK coverage Heat loss survey company Heat loss calculations guide

Handover

The winning survey is the one design and install can both use

For ASHP and GSHP work, the survey should not be a loose photo dump. It should show the evidence trail clearly enough that the next person can understand the property, the constraints and the assumptions.

Photos

Grouped by decision

Photos should sit with the relevant issue: siting, access, plant, electrics, emitters, rooms and constraints. That makes the report faster to check than a folder of timestamped images.

Assumptions

Measured, supplied and assumed data separated

A strong survey shows what came from the site visit, what came from plans or customer information, and what still needs confirmation before design sign-off.

Turnaround

A report the team can act on quickly

Vertex reports are built for installer handover: site evidence, measurements, photos and notes in one place, delivered through the portal so office, design and install teams are working from the same record.