Borthwick Design, Build and Management. Considering extending or renovating? We can help you unlock the potential in your home. We provide a free consultation to discuss your requirements and what we can do for you to make your space work best for you. We undertake planning applications including all plans and documentation, through working Drawings and documentation for Building Control. We can also provide interior and landscape design, introduce you to contactors to undertake the work and Project Manage the whole project on your behalf. Project sizes from a small extension through to new developments.