Experience has shown that the choice of a neutral venue is of vital importance to a successful mediation. All parties need to feel that they are in a private, comfortable, airy, and equally balanced environment. Not the stuffy, dark broom cupboard of the other parties legal representation which has just been cleared to make way for the mediation or indeed, a spare office with telephone or other conference facilities present that no-one knows whether they are or are not active and muted!
I usually recommend the use of meeting rooms in local hotels as the preferred option. They are readily available, offer balance, neutrality, a central location, free space in the public areas to break out too, public toilets and other facilities. They also offer the opportunity and free access to food, drinks and refreshments which are important to help maintain energy and concentration levels. Depending on the number of parties involved in the dispute, assuming a 2 party dispute, a minimum of 2 rooms are required, 1 for each party, however another is preferred, either for joint meetings or for myself to work out of.
As soon as the decision to mediate is taken, I would look to identify some options for mediation dates and the venue location that suits all parties. This helps to avoid further escalation in your dispute and focuses the parties with the preparation of case summaries and supporting documentation for exchange and review.
As it is not unknown for a mediation settlement agreement to be drafted and signed in the small hours, the venue is normally booked through until the next day to give the best possible chance of a resolution without the added pressure of having a vacate the venue and risk losing the flow of the mediation through to its final settlement.