GET / HAVE SOMETHING DONE
This construction is passive in meaning. It may describe situations where we want someone else to do something for us.
- I must get / have my hair cut.
- When are you going to get that window mended?
- We’re having the house painted.
If the verb refers to something negative or unwanted, it has the same meaning as a passive sentence:
- Jim had his car stolen last night. (= Jim’s car was stolen)
- They had their roof blown off in the storm. (= Their roof was blown off in the storm)
The construction can refer to the completion of an activity, especially if a time expression is used:
- We’ll get the work done as soon as possible.
- I’ll get those letters typed before lunchtime.
In all these sentences, we are more interested in the result of the activity than in the person or object that performs the activity.
‘X’ NEEDS DOING
In the same way, this construction has a passive meaning. The important thing in our minds is the person or thing that will experience the action, e.g.
- The ceiling needs painting (= the ceiling needs to be painted)
- My hair needs cutting (= my hair needs to be cut)