Last reviewed: 2 April 2026. This page is written as a practical checklist rather than a sales comparison.
Most avoidable re-questions do not come from exotic technical problems. They come from ordinary missing details: radiator sizes not recorded, cylinder space not shown properly, electrics photographed too loosely, or the outdoor-unit discussion left at “probably fine”.
What a usable ASHP survey pack should cover
| Area | What should be clear |
|---|---|
| Rooms and emitters | Room dimensions, emitter type, size, and anything unusual that affects sizing or replacement. |
| Existing heating | Boiler, controls, pipework clues, and anything that affects the transition path. |
| Hot water | Current cylinder arrangement, likely replacement position, and usable space around it. |
| Electrics | Consumer unit, supply details, spare ways, meter position, and obvious upgrade constraints. |
| Outdoor-unit context | Possible locations, boundaries, routes, maintenance access, and neighbour context. |
Details that are often missed
- Radiators photographed without a record of size or type.
- Consumer unit photos that do not actually show the detail the office needs.
- Cylinder and plant space captured too tightly to judge whether the replacement arrangement is workable.
- External routes described in words only, without photos that help the next person follow the logic.
Why this matters before design, not after
Once the quote is sent, missing information becomes more expensive. The design has to pause, the office has to chase, and the customer hears a more hesitant answer than they should. The simplest way to avoid that is still to gather the right information once, on site, in a pack the next person can actually use.
If you want to compare this checklist against a live layout, you can view the sample survey pack.