Which collector/source configuration is proposed (such as horizontal, vertical, pond/lake closed loop, or open-loop groundwater/surface water), and which site characteristics make that option relevant?
How the source options differ
A closed loop circulates fluid through buried piping. A horizontal layout uses land area; available space and soil conditions therefore matter. The guide describes vertical layouts particularly for larger-scale systems where land is limited or soil is too shallow for horizontal arrangements. A pond or lake loop depends on the water body’s volume, depth, and quality. These are alternatives, not a site recommendation.
An open loop uses groundwater from a well or surface water through the heat pump, then returns or discharges it. This option depends on adequate, relatively clean water and applicable local discharge requirements. The source, return route, water rights, and local rules for your property are unknown; ask which source is proposed and why.
What building-load and site/resource information supports the proposed configuration, and which values or conclusions must come from a site-specific designer assessment?
What a site-specific design needs to account for
The design discussion should connect the home’s peak heating and cooling loads with the ground-side resource. For a ground-coupled loop, relevant resource characteristics include the soil’s ability to transfer heat and how its temperature behaves. For groundwater, relevant characteristics include water temperature, well flow, and water quality. For a surface-water source, seasonal water-temperature patterns matter. These are categories of information, not conclusions about your lot or instructions to perform a particular test. Ask the designer to identify the actual values, their source, and which conclusions remain uncertain.
Does the proposal identify the ground collector/source work, heat-pump equipment, and building heat-distribution approach as one coordinated scope, while keeping any local water, drilling, land, or permit requirements explicitly jurisdiction-specific?
Compare coordinated project scope
Compare proposals for the same home’s heating and cooling goals. Ask each to identify the collector or water-source work, the heat-pump equipment, and the connections to the building’s existing or planned heat distribution. Ask what site and load assumptions connect those parts, what work is included or excluded, and who resolves unknowns. Do not assume that existing ducts or other distribution are compatible or that particular changes are needed. Ask which local land, water, drilling, and permit questions require separate confirmation for the site.