Red-lined sets of plans are plans (blueprints) that have been corrected or modified in the field because of errors or owner’s changes.
For multi-unit production tract housing and condominiums, red-lined plans are usually generated during the construction of the sales models which constitutes the trial-run phase before full-scale production begins.
The construction of the sales models provides the time-period in the project when the construction is debugged and the owner makes interior floor plan and exterior elevation changes.
The red-lined plans are then given back to the architect and engineers for revision so that a correct, updated set of plans can be used for the remainder of the construction.
Red-lined plans enable the builder to identify common mistakes to look for on future plans.
For example, laundry closets typically dimensioned 30 inches deep by the architect might be too tight for some brands of clothes dryers when the inclusion of the dryer vent hose and the gas pipe are taken into consideration…resulting in the wood bi-fold door bottom metal guides rubbing against the fronts of the appliances…for lack of space.
I have seen plans that mistakenly show a bedroom wardrobe closet opening width of 5 feet—6 inches…when standard 2-foot 9-inch wide closet doors do not exist.
These types of errors should become part of a growing checklist the builder uses as they analyze the plans before the start of every new project.