Bulkified Contact Trigger That Creates An Account?

First off, you need to do this after insert since you need a contact Id to reference. Second, you should use DeveloperName not Name. Third, don't reference RecordType.Id in the creation, instead use RecordTypeId:

trigger CreateHouseholdAccount on Contact (after insert) {

    RecordType arec = [SELECT ID FROM RecordType WHERE sObjectType = 'Account' AND DeveloperName = 'Household'];

    Map<Id, Account> aMap = new Map<Id, Account>();

    for (Contact con : trigger.new){
        if(con.AccountID == null){
            Account acc = new Account();
                acc.name = con.FirstName + ' ' + con.LastName + ' ' + 'Household';
                acc.RecordTypeId = arec.Id;
            aMap.put(con.Id, acc);
        }
    }

    if (!aMap.isEmpty()) {
        insert aMap.values();

        List<Contact> cList = new List<Contact>();

        for (Id cId : aMap.keySet()) {
            Contact con = new Contact();
                con.Id = cId;
                con.AccountId = aMap.get(cId).Id;
            cList.add(con);
        }

        update cList;

    }

}

Also we can use

List<RecordType> arecList = [SELECT ID FROM RecordType WHERE sObjectType = 'Account' AND DeveloperName = 'Household'];

and use arecList.get(0) in places of arec;

or use Try Catch method to execute SOQL.

We may never know when SOQL would fail.