We use data from over 100 of the UK's top surveying companies to create our Availability overlay - we currently have over 23,000 records (and growing).
In our Essentials subscription, we automatically populate Availability on the map (where relevant) as dark blue Availability 'dots' - clusters of properties/sites based on postcodes (image below). Click the dot to be shown a selection of sites, click a site to be taken to the agent's sales particulars.
In Elite, we show Availability either on the Title outline itself - which changes to dark blue - or in a dark blue postcode 'dots'. See the key below.
Once you click on the blue Title outline (polygon) the Information Panel opens and you can click on the Availability tab and the link directly to the agent's site:
If you click one of the Availability dots, a new window opens with the sites listed in the corresponding postcode with clickable links direct to the agents managing the properties/sites, as in Essentials.