Our Ropetrack solution is an excellent method for fixing shade sail structures to buildings as it uses and aluminium extrusion as shown in the picture. The "C" channel sections accept the rope sewn into the perimeter of the sail and enable a flush mount to the wall being used. The single most important advantage is that it spreads the loads applied by the sail across a larger area than a single wall plate fixing can achieve. Based on the picture, the ropetrack is secured across the entire fascia (or to a wall) which is also reinforced and secured back into the roof rafters of the house, and thus the whole roof of the house is accepting part of the load of the sail.
Quote me for custom made shade sails with a ropetrack
Note that typical fascias are merely nailed into the roof rafters, and are inadequate as such to support these shade sails structures. The fascia must be reinforced heavily, with brackets bolted through the fascia and into the roof rafters.
If you select allowance or actual the side that has the ropetrack will always be produced to the length specified. If you select allowance only those points will buckles will be reduced to allow for fixings.