A sketch floor plan is drawn to record the basic room layout on each floor and identify which rooms have fixed heat sources.

Assessment of where the property might adjoin other dwellings or commercial buildings and which walls are direct to outside (to determine the rate heat is lost through the structures).

If applicable and safe to do so, access is required to all loft areas to record insulation type & thickness. (The surveyor can provide a ladder if required).

Record how the dwelling is heated and how the system is controlled.

Obtaining photo evidence of everything itemised in the report in the event the assessment is selected for an accuracy/quality control audit (no extra visit is required - an audit is desktop only from site notes provided by the assessor.)

Detailed examination of the external structure to determine the construction type and how well heat is retained by the materials used. The values are pre-set in the software as designed by BRE. (Building Research Establishment).

Identifying the glass type (single/double/triple), glazing gap, frame type, (metal/timber/UPVC), compass orientation and m2 area of every individual window. Where possible, determining the age of each window to allocate the correct thermal performance.

Identifying the wall type/s from thickness and brickwork bond, noting any retro-installed insulation (cavity fill, internal or external).

Identifying vents/outlets where air is naturally escaping or mechanically extracted.

Applying the appropriate U-values (thermal performance) for each different element and area.

A brief walk-around of every room in the dwelling to count heaters/radiators (and the proportion having thermostatic valves), number & type of opening windows and proportion of low energy lighting installed in the fixed wiring circuits.

For centrally heated dwellings, verifying the exact make & model of boiler and method of heating domestic hot water (usually the same boiler). Ascertaining how boiler running-time and room temperatures are controlled - normally by programmer, wall mounted thermostat and sometimes individually adjustable radiator thermostats (TRV’s). Where installed, the type of individual supplementary heaters including the fuel type used.

On regular non-combi systems, measuring hot water storage tank capacity, insulation type and if temperature is independently user-controlled by cylinder thermostat.