With these prefabs, there was a move away from brick, using instead timber frames, steel frames and aluminium frames. There are indeed certain similarities between the postwar prefabs and modular homes that are going up, albeit in small numbers, today. Modular homes are built in sections in a factory setting, then transported to the site. There, they are placed on a pre-made foundation, joined and completed by the builder.

With modular housing, a significant percentage are timber framed with a concrete base. They are relatively bespoke, and purchasers can request that additional features be incorporated into the design, such as plaster and glass components. The idea is that the parts can essentially be bolted together. The components come in the back of a lorry and are put together onsite. It's like one big flat-pack house. 

Modular homes can be built quickly and efficiently, with the ability to add on to the property later. As the buildings contain embodied energy, which is locked into the fabric as a result of the construction process, they represent a uniquely sustainable form of construction. In the case of traditional buildings, this energy is lost when the house comes to be demolished. In the case of modular builds, though, the embodied energy is preserved when the building is relocated to another site, thereby reducing the impact of landfill. 

There are various types of modular homes. They can include, for instance, zero-carbon homes, which are dwellings that have no net carbon emissions from their energy use. This can be achieved through reducing their energy use using renewable energy, or a combination of both. So, features could include solar-panelled roofs and special insulation panels. As I stated earlier, most modular homes are likely to be energy efficient in any case, due to the sustainable materials that are used to construct them. But incorporating some of these other features would mean that you could have modular homes that also qualify as zero-carbon homes. In theory, some of these could actually generate more energy than they use, and could end up exporting energy to the national grid. Some Members here today have seen this in action at the SOLCER house project, constructed by the Welsh School of Architecture, which is Wales's first low-cost smart energy house.

Another relatively new idea is the shipping container home. These can be commissioned very quickly with manufacturers claiming that they can move from receiving their order to delivery in less than four weeks. The units are modular and can be stacked or placed side by side, or back to back, to either extend the living space or to create blocks of units. In Bristol, a project has been under way for about a year to help 40 homeless people through the provision of container homes. Bristol City Council have given them a plot of land to secure the future of the project. The Welsh Government have indicated that they feel the shipping container idea could help with the homeless problem in the short term. 

Another type of modular home is a self-build home. A survey conducted by the Building Societies Association in 2011 suggested that 53 per cent of people, more than half the population, would consider building their own home given the opportunity. On one of the UK's leading plot-finding websites, there are currently wanted adverts for 60 self-build homes in Wales. The UK as a whole has had a much lower rate of self-building than other European countries. The sector makes up less than 10 per cent of new builds here, whilst in Austria it is some 80 per cent of housing completions. In France, it is close to 60 per cent, and the same applies in Germany and Ireland. In the USA, it is 45 per cent. The Netherlands is closest to the UK in western Europe, but even in the Netherlands the total is close to 30 per cent. 

In England, under the Housing and Planning Act 2016, local councils have to consider how they can best support self-build. There's no such obligation on local councils in Wales currently. In 2013, a report by the University of York identified a series of challenges to self-build projects. These include land supply and procurement, access to finance, the planning process and general regulation and red tape. On the important issue of finance, lenders tend generally to perceive self-build loans as a higher risk. There's currently no Welsh Government grant available to people who want to self-build.

The Welsh Government did relax some planning requirements to enable the development of Lammas, a rural eco-village in north Pembrokeshire, so there has been some flexibility in this field.

We appreciate that the Welsh Government is doing things in the field of innovative housing. We aren't trying to have a go at their endeavours. That isn't the purpose of today's debate; we are just floating the idea of some specific proposals that may help to achieve the aims that we all share of providing more and better affordable houses in Wales.

We want to review the planning process so that we can remove some of the red tape. So, what they have done in north Pembrokeshire we'd like ideally to extend to the whole of Wales. We'd ask for the same obligation on local councils to allocate land for self-build projects that they have in England, so there would be a duty on councils to set aside plots for self-build in their local development plans.

Land banking is a problem that has been acknowledged by the Welsh Government. Finance Minister Mark Drakeford has floated the idea that taxation powers could be used to tackle the problem of land banking in the form of a vacant land tax. Now, that is a tax proposal that might well attract support from UKIP, because we want to ensure that where land has been purchased housing development does take place in a fairly short time period. But, we will await the specific tax proposals from Mark Drakeford and we haven't put anything down in the motion today on that issue.

What we have called for is a housing development corporation so that brownfield sites can be purchased quickly and cost-effectively. We think that an organisation set up with specific expertise in the field of property can help facilitate building on brownfield sites. Compulsory purchase orders, or CPOs, could be used to acquire these sites if there was no development within a period of three years. So, that could be an alternative to the idea of taxing vacant sites, or they could possibly work together.

We need a body to identify these sites in the first place, so our final proposal is for the housing development corporation to also compile a register of relevant brownfield sites that could be developed in Wales. So, those are our proposals and we are eager to hear what other Members think of them, so we avidly await your responses.