Anónimo preguntó: we need to ____________doing all the jobs in the house that we haven´t done for ages.

I imagine that the answer is start.

We need to start doing… is a verb pattern, and a pretty good one. 

need + to + infinitive

start + gerund

Other examples would be:

He needs to start exercising more.

You need to start going to the dentist.

She needs to start paying her bills on time.

Enjoy!