# The Extension Works > The Extension Works designs and builds single-storey rear extensions in the UK. We offer an instant online quote with a live 3D configurator, a fixed all-in price that includes Building Control fees and inspections, and online booking with a deposit. Customers also get a client portal for plans, payments and build-progress photos. ## Key pages - [Home](https://theextensionworks.co.uk/): Overview of the service and a link to the instant quote. - [How it works](https://theextensionworks.co.uk/how-it-works): The step-by-step process from postcode check to completion. - [Get a quote](https://theextensionworks.co.uk/quote): Instant pricing for single-storey rear extensions via a 3D configurator. - [Extension rules](https://theextensionworks.co.uk/extension-rules): Plain-English guidance on Permitted Development vs planning permission, plus published prices. - [Gallery](https://theextensionworks.co.uk/gallery): Photographs of completed extensions. - [FAQ](https://theextensionworks.co.uk/faq): Answers to common questions about cost, timescales and the build. - [About](https://theextensionworks.co.uk/about): Who we are and how we work. - [Contact](https://theextensionworks.co.uk/contact): Phone, email and enquiry form. ## Legal - [Workmanship warranty](https://theextensionworks.co.uk/legal/warranty) - [Privacy policy](https://theextensionworks.co.uk/legal/privacy) - [Deposit terms](https://theextensionworks.co.uk/legal/deposit) - [Cookie policy](https://theextensionworks.co.uk/legal/cookies)