As I've just started to work my way through each episode to get all the locations collated for the list, I was intrigued by a few things I discovered along the way regarding how the producers got around hiding some glaring modern day objects.
In the first picture below, you can clearly see a white burglar alarm box above the door.
In the next picture, you can see that the production team removed the alarm from the finished footage by colouring over it but crudely leaving it's shadow. Blink and you'll miss it!
In the next image, you can clearly see the row of houses have a collection of alarm boxes along the street (indicated)
In the next image, you can see that the production team very crudely drew over the alarm boxes with sampled sections of brickwork. Again, blink and you'll miss it!
And another twist....
In 2006 during filming, the houses all had a satellite dish, which explains the size of the covering sample in post production.
At the time of its broadcast I wasn't aware of how they had to use cgi editing to produce the series. When I watched it I didn't notice all these bits. Interesting to comb through it and find all this stuff right under your nose. I think that they had a lot of work to go through, presumably frame by frame so i guess they only did the bare minimum.
I bet the majority of the public didn't really notice it either as you tend to be drawn to the characters on screen.