Free roof space is only the starting point
A roof that looks clear may still raise issues: the condition of the material, the structure, leaks, and areas that must be kept free for other uses. Preparing information before the survey team arrives helps you point the questions where they matter, instead of rushing to conclude from a single photograph that the roof can take a solar system.
U.S. Department of Energy guidance names roof age, condition, strength and shading as factors in suitability. This article uses that only as a framework for asking questions; overseas building criteria or roof-orientation advice are not a substitute for design work carried out in Thailand.
Collect the roof history you actually know
Note the year of construction or renovation, the roofing material as far as you know it, the history of leaks, sheet replacements, and the points that have been repaired. If you have before-and-after photographs, work orders, or details of the previous contractor, file them by period. Do not guess at a year or a material where you are not sure.
Mention any roof repair you are considering — replacing sheets next year, or a leak whose cause has not been found. Those points should be assessed by the relevant teams for sequencing before installation positions are fixed, because work carried out at different times may require removal, relocation or extra protection of equipment.
Keep the drawings separate from the building's current state
Prepare the architectural drawings, structural drawings and any records of extensions you have, with the date or revision of each document. Identify what has changed since the drawings — an added awning, relocated rooftop equipment, new services. Do not treat old drawings as proof that everything on site is still the same.
If there are no drawings, say so before the appointment so the surveyor can plan what extra information to collect. The building owner does not need to calculate load-bearing capacity, and no one should cut, drill or add fixing points on the basis of an assumption. Assessing the structure and the installation method is the job of a qualified person responsible for that work.
Record shading with times and surroundings
From places you can reach safely, record which neighbouring buildings, trees, water tanks or installed equipment may cast shade onto the roof. Where you already have photographs, note the date, time and angle. A single midday photograph may not describe conditions in the morning or afternoon, and shadows also shift with the seasons.
Flag what you expect to change, such as a confirmed extension on a neighbouring building or a plan to move a water tank, keeping confirmed information separate from expectation. Do not cut someone else's trees or enter land without permission to make the data look complete — let the survey team specify how to check further.
Identify shared areas and access constraints
List skylights, vents, drainage routes, existing equipment and the routes maintenance staff need for normal operation, and send them for consideration alongside panel positions. Do not require every square metre of roof to be used until there is no way to maintain it.
Working at height should be within the plan of a responsible party with the right equipment and procedures. The building owner should not climb onto the roof to take a complete set of photographs, especially at fragile points or on a wet roof. Instead, coordinate access times, the site supervisor and any indoor work constraints from ground level.
Use the survey to separate what is settled from what needs more checking
After the survey, ask for a summary of what is confirmed, what needs further checking, and what repair or assessment is needed before the next design stage. A hypothetical example: there is enough space, but the leak history is unresolved, so fixing the leak should be separated from deciding system positions. Enough space does not equal ready to install.
Kintury Energy lists roof structure survey, sun orientation and equipment space in its service steps. Collecting this information makes the consultation fit the actual building, while conclusions on suitability, system size and necessary work still depend on the survey and a real assessment.
