Development of a database-supported web application that enables customers to select equipment for their homes, calculate the additional cost, save their selection, and output it as a PDF report. Divided into BackEnd (employee view) and FrontEnd (customer view). 0. General 0. a) The application only needs to be usable in German. To facilitate development, all texts can initially be stored in English in a single file, which we will translate later. 0. b) We provide an Apache web server with PHP, MariaDB, and FTP access. Development and beta versions should be made available on this server. 1. BackEnd 1. a) Creation of customers. Automated sending of login password to the customer by email. 1. b) Creation of construction projects. This includes input fields for: rooms and, in particular, bathrooms with the options (toilet, shower, bathtub) per bathroom; floor space per room; prohibited floors per room; facade area; running meters of balconies; running meters of interior balustrades. Assignment of the construction project to the customer. A customer can have several independent construction projects. 1. c) Creation of items with title, category, description, images, and additional cost. Option for the customer to enter quantities (e.g., number of indoor air conditioning units, outdoor water taps, etc.). Storage of sizes or colors for individual items (e.g., PV system output, tile dimensions, etc.). Different surcharges depending on color or size. Instead of specifying a price, option for customer note that consultation will be necessary (pool system). Items can be hidden with date selection for future projects. Surcharges are defined per calendar year. The price table is selected according to the date of creation of the construction project and is retained even at the turn of the year. It is possible to manually change the assignment to the price table. 1. d) Defining the categories and their order. 2. FrontEnd 2. a) Logging in with the previously generated access data and selecting the construction project. Several configurations can be saved per construction project. A completed configuration cannot be changed. An editable copy can be created. All configurations can be exported as PDF files. The customer can reset their password independently. 2. b) The customer goes through all categories to configure the construction project. Individual rooms within the categories are expanded using an accordion display. Display of completed categories and rooms. Display of the overall progress of the configuration. The total additional cost is always displayed. The process can be exited at any time and resumed at the last completed position. 2. c) Prohibited options are grayed out (e.g., floors not available for the construction project). The flooring is selected for each room and calculated based on the area of the room. The facade is calculated based on the area. If there are multiple bathrooms, the selection is made for each bathroom. For the ventilation system, the calculation is based on the number of rooms. For the electrical installation: Note that the customer will receive a separate quote. 2. d) The standard option at no extra cost must be actively selected by the customer. 3. Pricing 3. a) Your quote is binding. An increase of more than 25% during processing will not be accepted. If you do not agree to this, please do not submit a quote. 3. b) We define the following milestones: Milestone 1 — Infrastructure & Foundations: 15 % Prepare dev/test/beta deployment structure Create localization structure (English text file for all UI strings) Set up user authentication fundamentals (password hashing, reset token logic) Backend + database for customers Customer creation UI + automatic email dispatch of login data Construction project model (rooms, bathrooms, areas, prohibited floors, facade, meters) Project creation UI and linkage to customers Price-table assignment logic per project (with manual override) Milestone 2 — Item, Pricing & Category Management: 15 % Data model for items, variations (color/size) Admin UI to create/edit/hide items with images Support for “consultation required” items Quantity-based item definitions Future visibility of items Milestone 3 — Customer Frontend: Access & Configuration Lifecycle: 20 % Customer login page Project selection interface Create/edit configurations per project Lock completed configurations + create editable copies Autosave of configuration progress PDF export of configurations Milestone 4 — Configuration Wizard: UI & Calculation Logic: 30 % Guided category-by-category wizard Accordion room/bathroom displays Progress indicators for categories and rooms Real-time total cost calculation Greyed-out prohibited options All calculation logic: Flooring based on room area Facade based on facade area Bathrooms per bathroom instance Ventilation based on room count Electrical installation: special notice Mandatory selection of standard (zero-cost) options Milestone 5 — Finalization, Translation & Deployment: 20 % Full system testing and bug fixing Translation of all strings to German working Beta deployment to server Feedback improvements Production go-live