Greg Clark’s appointment as Secretary of State for Communities and Local Government was principally about housing. As we have regularly argued, the opportunity to own a good home is a fundamental element of a conservative society, and there remains a serious lack of available, affordable housing for people to buy. The Coalition’s mortgage subsidy schemes enabled some to gain the opportunity to become homeowners, while also inflating the price for the rest. The extension of Right to Buy to Housing Association properties is the right thing to do, but even that will also require housing stock to be replaced if supply is even to be maintained. The Starter Homes policy should help to open the market up somewhat by cutting taxes on housebuilding, but that, too, needs a construction industry which has the means, motive and opportunity to build.

Who better, then, to put in charge of the department which oversees house-building than the man who wrote the National Planning Policy Framework? By 2020 one of the main areas by which the new Government’s record is judged will be its performance on housing – the supply, the affordability and the changes in ownership will all count. Clark knows that he has a heavy responsibility to fulfil, and it is an open secret that his predecessor, Sir Eric Pickles, was felt by some at the top to be falling short on this measure, despite his many successes on other fronts.

Today sees the new Secretary of State’s opening shot on the topic – apparently he will tell the new Cabinet housing taskforce that he wants Whitehall departments to free up sufficient publicly-owned land to build 150,000 new homes.

That makes sense – the state remains Britain’s largest landowner, with the MoD alone owning over 228,000 hectares (over 1 per cent of the UK’s land mass). But there are three questions raised by this latest push:

First, will that land actually be opened up by Whitehall? After all, this was also meant to be the Coalition Government’s policy, but there was only limited success. For example, from 2012 to March 2014, under Philip Hammond’s careful watch, the MoD only shed 1,100 hectares in total, a tiny fraction of its total holdings. Under the Coalition, public land was used to build 103,000 homes – presumably using up a fair amount of the low-handing fruit of Whitehall’s combined property portfolio. Clark’s plan to build a further 150,000 during this term will require much more pressure on the departments to cough up.

Second, if sufficient land can be made available, is it all in areas that are useful or desirable for housebuilding? To continue the MoD example, for obvious reasons much of the Defence Estate is quite remote, used as it is for firing and exercise ranges. Such land is wild and beautiful but not necessarily near to many jobs, schools or hospitals.

Third, even if Clark’s demand is heard and answered by his colleagues, where are the rest of the new houses the nation needs going to go? 150,000 new houses built on public land would be welcome, and we support the push, but using public land can only ever be part of the solution to our housing problems. Consider the promised 200,000 Starter Homes, the new houses to replace those sold under the extended Right to Buy, and then the number required as part of the normal function of the market in a country with a growing population, and you realise that 150,000 is a good start – but still only a start.