diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 0000000..8e9be42
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,8 @@
+image: ubuntu:bionic
+
+build:
+  stage: build
+  before_script:
+    - apt update && apt -y install make cmake gcc
+  script:
+    - mkdir cmake-build && cd cmake-build && cmake .. && make
\ No newline at end of file
diff --git a/Building/Building.c b/Building/Building.c
new file mode 100644
index 0000000..c7b0b9b
--- /dev/null
+++ b/Building/Building.c
@@ -0,0 +1,4 @@
+//
+// Created by Antoine Bartuccio on 05/06/2018.
+//
+#include "Building.h"
diff --git a/Building/Building.h b/Building/Building.h
new file mode 100644
index 0000000..f0af2a6
--- /dev/null
+++ b/Building/Building.h
@@ -0,0 +1,23 @@
+//
+// Created by Antoine Bartuccio on 05/06/2018.
+//
+
+#ifndef LO41_BUILDING_H
+#define LO41_BUILDING_H
+
+#define ELEVATOR_NB 3
+
+#include "../Objects.h"
+#include "../List/List.h"
+#include "../Elevator/Elevator.h"
+#include "../CommunicationBox/CommunicationBox.h"
+
+typedef struct o_Building {
+	int floors;
+	List * residents;
+	CommunicationBox * box;
+	Elevator elevators[ELEVATOR_NB];
+} Building;
+
+
+#endif //LO41_BUILDING_H
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0f6d9b1..f358df6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,4 +4,4 @@ project(LO41 C)
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
 
-add_executable(LO41 main.c List/List.h List/List.c Objects.h List/Element.c List/Element.h Objects.c)
\ No newline at end of file
+add_executable(LO41 main.c List/List.h List/List.c Objects.h List/Element.c List/Element.h Objects.c Building/Building.c Building/Building.h Elevator/Elevator.c Elevator/Elevator.h CommunicationBox/CommunicationBox.c CommunicationBox/CommunicationBox.h)
\ No newline at end of file
diff --git a/CommunicationBox/CommunicationBox.c b/CommunicationBox/CommunicationBox.c
new file mode 100644
index 0000000..1fc7b63
--- /dev/null
+++ b/CommunicationBox/CommunicationBox.c
@@ -0,0 +1,5 @@
+//
+// Created by Antoine Bartuccio on 05/06/2018.
+//
+
+#include "CommunicationBox.h"
diff --git a/CommunicationBox/CommunicationBox.h b/CommunicationBox/CommunicationBox.h
new file mode 100644
index 0000000..ed572b9
--- /dev/null
+++ b/CommunicationBox/CommunicationBox.h
@@ -0,0 +1,14 @@
+//
+// Created by Antoine Bartuccio on 05/06/2018.
+//
+
+#ifndef LO41_COMMUNICATIONBOX_H
+#define LO41_COMMUNICATIONBOX_H
+
+#include "../Objects.h"
+
+typedef struct o_CommunicationBox {
+
+} CommunicationBox;
+
+#endif //LO41_COMMUNICATIONBOX_H
diff --git a/Elevator/Elevator.c b/Elevator/Elevator.c
new file mode 100644
index 0000000..c7d1ce5
--- /dev/null
+++ b/Elevator/Elevator.c
@@ -0,0 +1,5 @@
+//
+// Created by Antoine Bartuccio on 05/06/2018.
+//
+
+#include "Elevator.h"
diff --git a/Elevator/Elevator.h b/Elevator/Elevator.h
new file mode 100644
index 0000000..84f11d4
--- /dev/null
+++ b/Elevator/Elevator.h
@@ -0,0 +1,14 @@
+//
+// Created by Antoine Bartuccio on 05/06/2018.
+//
+
+#ifndef LO41_ELEVATOR_H
+#define LO41_ELEVATOR_H
+
+#include "../Objects.h"
+
+typedef struct o_Elevator {
+
+} Elevator;
+
+#endif //LO41_ELEVATOR_H
diff --git a/List/Element.c b/List/Element.c
index 96b1e1c..87058ab 100644
--- a/List/Element.c
+++ b/List/Element.c
@@ -12,7 +12,7 @@ GETTER(Element, void*, data)
 SETTER(Element, Element*, previous)
 SETTER(Element, Element*, next)
 
-void $_free__Element(THIS(Element)){
+void _free__Element(THIS(Element)){
 	List * list = this->list;
 	if (list != NULL) {
 		if (list->head == this && list->tail == this) {
@@ -35,7 +35,7 @@ void $_free__Element(THIS(Element)){
 	free(this);
 }
 
-Element *$_init_Element(void *data, size_t size, List *list){
+Element *_init_Element(void *data, size_t size, List *list){
 	Element *el = (Element*) malloc_or_die(sizeof(Element));
 	void *new_data = NULL;
 
diff --git a/List/Element.h b/List/Element.h
index b352337..09b38a0 100644
--- a/List/Element.h
+++ b/List/Element.h
@@ -30,6 +30,6 @@ FRIENDLY(data, List)
 FRIENDLY(next, List)
 FRIENDLY(previous, List)
 
-Element *$_init_Element(void *data, size_t size, List *list);
+Element *_init_Element(void *data, size_t size, List *list);
 
 #endif //LO41_ELEMENT_H
diff --git a/List/List.c b/List/List.c
index 41c89a4..547a946 100644
--- a/List/List.c
+++ b/List/List.c
@@ -54,7 +54,7 @@ void * get_tail_data_List(THIS(List)){
 	return NULL;
 }
 
-void $_free__List(THIS(List)){
+void _free__List(THIS(List)){
 	this->clear(this);
 	free(this);
 }
@@ -129,7 +129,7 @@ void remove_tail_List(THIS(List)){
 	DELETE(this->tail);
 }
 
-List *$_init_List(){
+List *_init_List(){
 	List *l = (List*) malloc_or_die(sizeof(List));
 	l->size = 0;
 	l->head = NULL;
diff --git a/List/List.h b/List/List.h
index 7850f7a..b4ac79c 100644
--- a/List/List.h
+++ b/List/List.h
@@ -43,6 +43,6 @@ FRIENDLY(head, Element)
 FRIENDLY(tail, Element)
 FRIENDLY(size, Element)
 
-List *$_init_List();
+List *_init_List();
 
 #endif //LO41_LIST_H
diff --git a/Objects.h b/Objects.h
index 2c53f84..c9dee21 100644
--- a/Objects.h
+++ b/Objects.h
@@ -8,9 +8,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#define NEW(type, ...) $_init_##type(__VA_ARGS__)
-#define DELETE(obj) obj->$_free_(obj)
-#define DESTRUCTOR(type) void (*$_free_)(struct o_##type *this)
+#define NEW(type, ...) _init_##type(__VA_ARGS__)
+#define DELETE(obj) obj->_free_(obj)
+#define DESTRUCTOR(type) void (*_free_)(struct o_##type *this)
 #define THIS(type) type *this
 #define _THIS(type) struct o_##type *this
 #define CRASH(message) perror(message)
@@ -35,7 +35,7 @@ void * malloc_or_die(size_t size);
 #define VA_NUM_ARGS_IMPL(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, N, ...) N
 #define LINK_NB_(N) LINK_ALL_##N
 #define LINK_NB(N) LINK_NB_(N)
-#define LINK_ALL(type, obj, ...) LINK(type, obj, $_free_) LINK_NB(VA_NUM_ARGS(__VA_ARGS__))(type, obj, __VA_ARGS__)
+#define LINK_ALL(type, obj, ...) LINK(type, obj, _free_) LINK_NB(VA_NUM_ARGS(__VA_ARGS__))(type, obj, __VA_ARGS__)
 #define LINK_ALL_1(type, obj, method, ...) LINK(type, obj, method)
 #define LINK_ALL_2(type, obj, method, ...) LINK(type, obj, method) LINK_ALL_1(type, obj, __VA_ARGS__)
 #define LINK_ALL_3(type, obj, method, ...) LINK(type, obj, method) LINK_ALL_2(type, obj, __VA_ARGS__)