Housing Minister Phil Twyford plans to build up to 4000 houses, but the National Party says the numbers don't add up. Yesterday Mr Twyford unveiled the plan to build the homes on roughly 30 hectares in the Unitec campus in Mt Albert. ACT Party leader David Seymour says it will be like cramming more than 100 houses into an area the size of a rugby field. And National's housing spokesperson Judith Collins says the homes will have to be incredibly tiny to fit. Housing Minister Phil Twyford tells Todd Niall the government hopes to start building within a year.