using (IModel model = CobieModel.ImportFromTable("MyCobieSpreadsheet.xlsx", out string report))
    {
        // Get all the contacts
        var contacts = model.Instances.OfType<CobieContact>().ToList();
        
        // Query the spaces but filter by a Uniclass2015 category. And then my the room area
        var largeCommercialSpaces = model.Instances.OfType<CobieSpace>()
            .Where(space => space.Categories.Any(cat => cat.Classification.Name.StartsWith("SL_20_50")))
            .Where(space => space.GrossArea > 1000);
        
        // We can then drill across to other parts of the model
        var occupancyRatingOfFirstSpaces = largeCommercialSpaces.FirstOrDefault().Attributes
            .Where(attr => attr.Name.StartsWith("Occupancy"));
    }

    const string input = @"SampleHouse4.ifc";

    var ifc = MemoryModel.OpenReadStep21(input);

    var cobie = new CobieModel();
    using (var txn = cobie.BeginTransaction("Sample house conversion"))
    {
        var exchanger = new IfcToCoBieExpressExchanger(ifc, cobie
            /*,     // More advanced configuration options available
            reportProgress: reportProgressDelegate,
            filter: outputFilters,
            configFile: pathToAttributeMappingConfigFile,
            extId: EntityIdentifierMode.GloballyUniqueIds,
            sysMode: SystemExtractionMode.System,
            classify: true*/
            );
        exchanger.Convert();
        txn.Commit();
    }

    // We can persists our model to disk for faster access in future
    var output = Path.ChangeExtension(input, ".cobie");
    cobie.SaveAsEsent(output);

    // We can fix up the data to make it valid - e.g. Deduplicate some names
    using (var txn = cobie.BeginTransaction("Make some changes"))
    {
        MakeUniqueNames<CobieSpace>(cobie);
        MakeUniqueNames<CobieType>(cobie);
        txn.Commit();
    }

    // Finally export as a COBie spreadsheet
    output = Path.ChangeExtension(input, ".xlsx");
    cobie.ExportToTable(output, out string report);