After analyzing your issue, it seems that the best approach would be to export your Header and Footer components as a separate Angular Module marked as "private". This way, you can easily reuse them in any new project.
For instance:
Project 1
import { AppComponent } from './app.component';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { BrowserModule } from '@angular/platform-browser';
...
import { YourHeaderModule } from './your-header.module';
@NgModule({
declarations: [ AppComponent ],
imports: [
BrowserAnimationsModule,
BrowserModule,
...
YourHeaderModule
],
providers: [],
bootstrap: [ AppComponent ]
})
export class AppModule { }
This allows you to utilize your Header and Footer modules similarly to Material Modules/Components.