Dynamic Castle/room placement system for a base building game in Unity Using C#

The project is to create a castle building system for the base building game, which will dynamically place walls/rooms down in run time. using Unity c#. To understand what I Want is best to view the video of Software inc example I uploaded. (Build room video) So basically I want to replicate this room placement system, but with rooms being combined at the end and removing the wall dividing those rooms always having one big single room … why ? because in my game the outside walls are castle walls and they look different from inside room walls, so I need this system changed to include ability to add different wall types inside after we built main enclosure... Build room 2 video shows room placements and manual removal of wall , but I need this done automatically /dynamically... more about it; System would allow player to click with a mouse anywhere on the grid and draw a square shape room enclosure, any size he wishes, then another click should place down all walls and corners as seen in software inc game... please see video and picture attached... Then we should be able to expand this castle area by drawing another area just next to it same way , but unlike software ink, I want the wall dividing these 2 areas Removed and rooms combined into a one single room space. a standard room Enclosure is made out of; 4 corner pillar prefabs 4 wall segment on each side 1 Floor tile and 1 ceiling tile as seen in a video in order to place a building player needs to have enough money … the bigger room the bigger cost … which is charged per square unit, cost can be anything even wood or stone , both or more … the ability to have more then one requirement would be better. I am Using manufacture's building pieces, all walls are 3 L x 3 h and floor tile is 3x 3 , thus I will need System to place room area on 3x3 grid as a single unit , means smallest room area player can ever draw is 3x 3. Not to get confused I don’t want to call this area rooms because they are not rooms at all, they represent the outside castle walls and I call it enclosure with one big empty space inside where all other rooms will be later placed… So think of Castle Walls as enclosure, And rooms that will be placed inside as compartments Later on we will place rooms inside this enclose, place doors and windows and add some features like room stats… For more please read the document provided and please view the video attached Who should apply; Someone who loves creating games and has an interest and understanding of base building games such as Software inc, Theme Hospital, 2 point Hospital, Fallout 4- base building part, RimWorld and so on, Someone who understand the idea behind these games and how they work. Mostly someone who posses the skills to create a dynamic room placement system and knows how to spawn /draw prefabs and other objects in run time . Please don’t be cheeky and bid a small amount to get me to offer you a job and then not be ready to work for the amount you bid yourself … I find it very unethical and uncomfortable… in my last project 3 people have done this sneaky strategy, getting my attention with a small bid then trying to re – negotiate what they bid , because I also pick you based on what you bid as well as your reputation and skills , so please be professional, hard working ,polite , devoted and most importantly responsive, please don’t ignore me , and keep me regularly updated with the progress and issues … Thank you in advance for reading this and your interest in this project