For this timber-board reveal windows project in Lymm, opening checks, frame fitting and finishing are treated as one sequence. Installation Access leads the review, so we plan handling and working access before existing frames are removed. We use reveal dimensions and fixing points around board depth, frame setback, end returns, seal line and decoration, ensuring we check internal and external reveal depths so trims, plaster and handle clearances can be coordinated and position frame fixings to suit the opening, frame profile and surrounding substrate, with installation access kept as the lead check for this timber-board reveal windows scope. The last technical check is internal sealing; we close the internal frame perimeter cleanly before trims or making-good work is completed, with installation access kept as the lead check for this timber-board reveal windows scope. This supports timber internal boards aligned neatly with the replacement frame and reveals.