Thousands of prefab, trailer-type "caravans" and "caravillas" dot the landscape of Israel and the territories. Apart from their well-known use as portable, temporary housing for settlers on disputed land, they have also been utilized to house immigrants and for educational facilities such as kindergartens, classrooms and offices, especially in ultra-Orthodox communities that are unable to finance permanent structures. Synagogues in trailers, too, are common sights at Israeli army bases.

If we put aside personal views on the settlements for a moment, we can focus on the design quality of what has been done to date.

At Nitzan, an entire neighborhood of hundreds of caravillas - larger versions of the caravan trailer, transported to the site in two sections that are then joined - was constructed after the 2005 "disengagement" from Gush Katif in the Gaza Strip. Paid for by the government, these structures were set up in rigid rows like barracks, their red tile roofs hardly masking their banal design. More recently, tens more were ordered to house those families evicted from the Ulpana neighborhood in Beit El.

Caravillas don't come cheap. The cost of buying and setting up even a small, 60-square-meter unit, providing it with access to vehicles and pedestrians, hook-up to utilities and a security room, is well over $100,000.

The mechanical ordering of identical residential units, oblivious to the social and cultural context of their residents, is unacceptable. Judging by the amateurish results - of which Nitzan, Beit El and also Migron are but a few examples - there is little reason to believe that any one of the ministry officials who buy the units have ever seriously studied the matter. Isn't it time they did?

What they would find, for one thing, is that the temporary in this case has a cunning way of becoming permanent. The dilapidated caravans still standing today in the Givat Hamatos neighborhood in Jerusalem, built in 1991 to house mainly Ethiopian immigrants, are proof enough of that. What is required instead is the same sort of care that is invested in the design of a permanent neighborhood or school.

If there is to be any hope of improving this situation, it must first be realized that we can no longer remain at the mercy of manufacturers whose main goal is maximum profit in the short term. Nor can we leave the matter in the hands of government bureaucrats who long ago proved themselves incompetent. Making better prefabs with flexibility built into them, allowing for interesting combinations of units, is one idea. Recycling shipping containers, as has been done in Japan and elsewhere, is certainly cheaper.

When it comes to housing, diversity and choice are critical. Combining individualized modern design with mass-customization should be a primary goal. Emphasis must be placed on the ability of the chosen prefabs to be organized in groups so as to form space-enclosing clusters that would allow for social interactions. The free-standing, single-family trailers and caravillas we have become accustomed to take up a great deal of valuable land, increasing costs of construction and infrastructure. Multistory, multifamily temporary housing alternatives, never pursued here, offer a far more efficient and economic strategy. "Villages" - yes, "villas" - no.

Temporary-home design criteria should ideally also include the following: They should be lightweight and compact for easy shipment; be capable of being set up without the need for foundations and without causing significant damage to the terrain; be almost totally prefabricated, and weather and fireproof; self-sufficient and ready for immediate use; stackable (up to three stories ), durable, ecologically sustainable and modular; easily dismantled, aesthetic and of course, reasonably priced. Unfortunately, few, if any, of the above criteria have been met in the thousands of units erected here to date.

Design tactics that meet these criteria, and that have been experimented with worldwide, include all manner of compact, easily transportable building kits that unfold, slide, roll out, plug in, blow up or boot up in various ways once they arrive at the site.

Much can be learned from Japan's efforts in providing emergency housing for its homeless citizens in the wake of the 2011 earthquake and tsunami disaster. A project of 189 dwelling units, made of recycled shipping containers stacked two and three stories high, constructed in Onagawa by Shigeru Ban Architects, provides us with an instructive example. Each building block is a vertical checkerboard of containers staggered for noise control. Private areas such as sleeping quarters are contained within the containers, while the kitchen and dining areas occupy the void (glass-enclosed ) space between them. Displaced people need fast solutions. Ban's housing went up in just three months.

A temporary school made of caravan classrooms surrounding a shared shaded open space has been constructed at Moshav Nehusha south of Beit Shemesh. Positive examples need to be sought out.

Given the certain continuing demand and urgency, temporary housing and school design is most certainly deserving of in-depth research and development by our finest architects. Prototypes suitable to the Israeli context should be sponsored by the various government ministries - with housing, education, absorption and defense being the major clients. The sooner we put an end to the travesty of the ugly (and extremely costly ) trailers and caravillas defacing our landscape, the better. Architecture can be made of temporary housing and educational facilities. If the land is the Lord's, why destroy it?

Gerard Heumann is an architect and town planner in Jerusalem.