Diagonal have adopted the principles of Constructing Excellence, a practice that exists to improve our industry's ability to create a better-built environment. From procurement methods to choice of materials, Diagonals use of the Constructing Excellence principles guarantee that your home is built or renovated to the v ery highest of standards, both in terms of quality and environmental considerations; We would advise that our work is carried out under ‘JCT 2005 Constructing Excellence contract’ which allows for complete transparency in costing information with a guaranteed mark-up for Diagonal based against an agreed target cost model.