I'll try to keep this concise, but there's quite a lengthy background.
Basically, we have had a problem with sewage leaking up through the floor into our lounge due to a blockage in the drain over which the extension was built some 25 years ago.
We first noticed the problem and reported it to the property managers almost 3 weeks ago; since then they've sent out engineers to clear the blockage and contractors who have confirmed that the entire floor needs to be ripped up (laminate flooring), part of the wall replastered and everything chemically treated before new flooring can be laid. However, it is almost two weeks since any work has actually been done because everyone's hands are tied by paperwork and the insurance company taking their merry time to process stuff.
In the meantime, we have asked for our rent payment this month to be refunded, partly because we can't live in the house but also because it has cost us a lot of money in fuel (travelling to stay with family) and storage materials for our belongings (we've had to empty the lounge of every scrap of furniture and 'stuff'). The property managers said this would only be possible if the insurance company declared the house uninhabitable as then the LL will be able to claim for loss of rent. However, they also advised us that the last contractor ticked a box on his report saying "alternative accommodation not required" and this usually means the insurance company will see the house as fit to live in.
My argument is:
- The lounge is the only reception room, so we currently have no usable downstairs space.
- The only access to the kitchen is through the lounge
- Though the blocked drain has been cleared, there's still a massive hole in the floor and the boards are all soaked in sewage water. Walking through the lounge means exposure to this & potential cross-contamination of the upstairs carpets.
You couldn't present this house to prospective tenants if it was empty & market it as ready to live in, so how could we be expected to live in it with four small children?
The woman I've been dealing with at the property management company agrees that living in the house is unbearable; Environmental Health said it sounds like the insurers should cover alternative accommodation. Basically everyone I've asked seems staggered at the idea that we could be made to pay full rent & live here until the floor is replaced but the insurance company are very likely to say just that, based on this one stupid tick box 
What can I do? We don't want to move to another house altogether, but once the work ripping up the floor starts, we'll lose access to the kitchen so will need to move in with PIL (who live on the opposite side of town to dc's school, meaning that the school run will entail £160/month of train fares at the very least). I just can't see how they could reasonably expect us to continue paying as full tenants.
Any insight would be much appreciated. I'm going to speak to the CAB tomorrow if I can too.