Property Renovation Cambridge by Design Build Renovate Maintain. Delivering professional property renovation in Cambridge. Maybe you require a new bathroom installation, or just painting and decorating. Whatever your home needs we have the right tradesman or team of tradespeople. All property refurbishment projects are fully insured. We carry public and employer’s liability insurance for £5m and £10m respectively. Design Build Renovate Maintain also provide a 12-month warranty for all works we undertake. For loft conversion, garage conversion and home extension projects, we provide a 6-year warranty.