My my some people have managed to get on their high horse with this one!!
There is no legal obligation for landlords to make properties specifically child friendly. In this case the tenants have lived there for 5 years and still want to live there and have not complained that it's unsafe. They have just renewed their tenancy agreement, if they thought it was unsafe/unsuitable for a child they could have moved out. The panes of glass in the doors are small ones with wood framing. So, as one poster mentioned a child throwing a toy, I imagine this would break one or two of the small panes but not all the glass.
As far a insurance is concerned, my landlord insurance would definitely not cover accidents/fires whilst the nanny is working there as she is not the named tenant and obviously the named tenants wouldn't be there as they are at work. I also have emergency accommodation cover for the tenants if there was a fire/flood. The tenants under this arrangement would still pay their rent whilst the property was being rebuilt and then move back in when the work was done.
To all of you who think this is none of my business, you are definitely wrong here. If a tenant does anything that has the potential to invalidate the landlord's insurance, it definitely IS THIER BUSINESS. The most common reason a landlord's insurance is invalidated are when tenants decide they want one or more adults to move into the property without telling the landlord and therefore can not be named on the tenancy agreement. If one of these unnamed persons caused a fire in the property the insurance company would invalidate the claim as the policy only covers tenants who are named on the tenancy agreement. Likewise, the tenancy agreement specifies that the tenants use the property as a residential dwelling only. They now want a change of use to a place of work, this means the landlord insurance is invalid when the nanny is working there. I need to ascertain whether the tenant's employers liability insurance or the nanny's liability insurance covers a number of situations.
The tenants have become employers and now have legal obligations themselves.
I think I will suggest that they need to arrange for an independent health & safety surveyor to come around and assess the property for their purposes of providing childcare employment. It will then be their responsibility to implement any recommendations and proof to their insurance company they that have done a risk assessment.
I will then be asking a series of insurance related questions, for which they will need a lawyer to answers for them. If I don't get satisfactory answers to these I will have no option but to forbid them from employing a nanny.
At the end of the day, it is my flat and if there is a fire/accident there I need to be certain which insurance policy covers me for the damage/liability.