RICS survey guidance starts with the purpose, accuracy, features and deliverables required. [1]
Agree what is being measured
A measured building survey can provide floor plans, roof plans, elevations and sections. The chosen package should identify which parts of the building are included and how the information will be supplied. A site survey and an underground utility survey answer additional, different questions. [1] [2]
Before booking, ask the designer to specify the areas needed for your proposal. For example, request clarification about access to the loft, the rear garden and any shared spaces. Ask how inaccessible areas will be recorded so that a blank part of a drawing is not mistaken for a confirmed absence of structure or services.
Measurements do not prove structural adequacy
Recording a wall, beam or floor does not establish its load-carrying capacity. The engineer may need separate investigations into the existing structure, foundations or ground conditions. Coordinate those enquiries with the measured information rather than assuming that one visit answers every question. [3]
RICS also distinguishes a home survey concerned with property condition from other survey services. A condition report and drawings of the building should not be treated as interchangeable deliverables. [4]
Check the drains separately
A visible manhole is a useful starting point, not a complete underground record. Thames Water advises using a builder or drainage specialist to establish the location and size of relevant pipes, and acknowledges that sewers may be unmapped. [5]
Ask whether the project needs drainage records or further investigation before the footprint is fixed. Do not commission a generic survey package without checking whether it covers that need.
Use existing information intelligently
Give the team earlier drawings and surveys, together with any information about later alterations. Domestic clients must provide relevant building information they have, or could reasonably obtain, to those designing and constructing the work. [6]
Ask the receiving designer which existing information can be relied upon, which dimensions require checking and whether the proposed work needs information that the earlier documents never recorded.
What to keep in your project file
Request the survey date, agreed scope, supplied drawing formats and any limitations or inaccessible areas. Keep the original survey separate from proposed drawings so that existing and future arrangements remain distinguishable.
Before approving a design, ask: “Which important dimensions or concealed conditions are still assumptions?” That question is more useful than treating the word “surveyed” as a promise that every uncertainty has disappeared.