In this guide
What is installed, and will it stay?
Record the make and model from paperwork or an accessible label. Note whether the project keeps the appliance, changes an approved front or replaces the system. If the model is unknown, resolve that before treating the existing dimensions as a complete design brief.
Which measurements come from the manual?
Ask the project team to identify the instructions for the actual model, including relationships to surrounding materials and required access. A photograph of another home is useful for style, but it does not establish that the same proportions work with your equipment.
Can the fireplace still be serviced?
Think about routine access before permanent finishes are installed. Controls and serviceable components need to remain accessible as required by the manufacturer. Discuss the sequence with the fireplace and finish trades so that later service does not become a demolition project.
Who confirms scope, approvals and handover?
Keep the responsibilities explicit. Agree who confirms equipment compatibility, who handles any required review and what information you receive at completion. Save the appliance manual and project records together for the next owner or service visit.