1. Introduction
Wood is the most used material to meet housing requirements for different socioeconomic levels [
1,
2], no only meeting the requirements in emergencies, but also in being the “future sustainable solution in high-rise buildings in the world” due to a sustainability technically well-documented [
3,
4,
5,
6]. It is also the most accessible solution in rural areas given the wood availability, and the lack of access to state subsidies. Beyond the current legislation, it is mistakenly possible to reduce costs when acquiring houses with no sustainability attributes, such as energetic efficiency, and low carbon footprint.
What has been happening for decades, since in Chile the demand exceeds by far the housing supply, is a housing deficit higher than 650.000 homes, and to stop this deficit from increasing, 100.000 houses need to be fabricated annually [
8], for that reason the self-build is becoming more common [
2,
7,
9], or the acquisition of houses in alternatives housing markets with a large supply of building types, qualities, deadlines, from construction kits, to turn-key complete installation services. As providers, there are consolidated architectural offices, and/or construction companies, complying with technical criteria established until the final work reception. It represents an option for those with purchasing power, but not for those without, accessing in this case to substandard habitability, where the indicators of sustainability, and safety hardly ever exist, or are assessed. For a non-wood construction industry, which generates 35% of waste globally, with a 20% of water consumption, and with 40% of greenhouse gas emissions, sustainability is not an option, but a necessity. As a model, to promote this process, the International Living Future Institute launched in 2006 the strictest, and most sustainable green building program in the world: the Living Building Challenge. Through this program, around 20 buildings at global level seek to be certificated, confirming that they generate more than they consume through the certification “Net Zero Energy Building” (NZEB) [
11]. The architectural design, water management, ventilation, photovoltaic panels, orientation of the building, and windows are considered in this certification. That is to say, at global level, standards are higher each time, and, while wood has always been available as raw material, today it plays a new leading role. Meanwhile in Chile, strategic national programs have been promoting the wood potential during the past two decades, but this only represents from 10 to 12% of the formal construction. The state drives the energetic certification of buildings, and houses to increase the value of supply, and in terms of public building, it complies with technical regulation, however, there is a lack of technical regulation certification in the private market. Exceptionally, in high level projects, international certifications like Passivhaus, or LEED are included, highly exceeding national regulations. Up to now, wood structural construction does not exist in these buildings, except for some buildings created as a trigger effect, or other very specific corporations. [
9,
12].
The purpose of reflect on the vulnerability, and lack of sustainability of habitability when territorial conditions are no taken into account, setting homes in areas of risk, seismic exposition, volcanos, forest fires among other threads without understand its importance is what this investigation seeks to highlight, focusing on the supply of prefabricated wooden houses in three central Chilean regions: Valparaíso, Metropolitan, and O’Higgins. The results may be extrapolated to most of the Latin American territory, therefore giving a chance to this sector to manage processes related to sustainability, preparation, and preventive actions towards habitability conditions triggered by climate change.
2. Materials and Methods
In order to evaluate prefab houses that this productive sector is providing, this study was developed through a review of bibliographic sources, and online data, including web platforms, directories of business, publications by INFOR (Forestry Institute), SII (Internal Revenue Service) database, among others.
The study includes Valparaíso, Metropolitan, and O’Higgins regions in central Chile, considered due to their potential demand capacity.
To generate records on the companies selected to be studied, in addition to investigation online, and in social media where offers are being made, a search of information in the public market’s sales, official statistics, and Internal Revenue Service was carried out. Highlighting key words in search engines, using as model the ones used in [
10], to build sustainability indicators that this time were: 1.-Materialy (wood, biomaterials, others); 2.-Safety (earthquakes, fires, others); 3.-Bioeconomy (Reduce – Reuse – Recycler (R – R – R); 4.-Energetic efficiency, and thermal comfort. A directory of companies was created, and then the houses offered were evaluated based on an indicator built in
Table 2, with guidelines to evaluate considering complexity, regulation compliance, and sustainability, as detailed in
Table 1.
4. Discussion
In overall terms, it is determined that there are significant differences in respect of technologic capacity, and digitalization using BIM technology in the companies analyzed, with just a few over the majority in this feature.
The Technical Division (DITEC) from the Ministry of Housing, and Town Planning have announced the legal framework which will regulate the industrializing companies who are going to work with to decrease housing deficit [
17]. From the wood construction sector, four companies have been authorized, with social housing projects, and medium-rise buildings, which have been progressing in regulation compliance, using BIM technology in productive process, with a coordinated industrialization inside the factory, in order to allow the chaining with other providers. In such way, potentially, it is possible to make the wooden housing market in Chile to grow, and be developed even as an exportation product for Latin America.
[
19] In this investigation it is noted as a finding of the evaluation on thermal subsidies from the family property protection program, and its effects in overcoming the energetic poverty in Chile , that “there is no focus on the most vulnerable homes, and there is no responsibility taken by the program staff, and its poor management, in addition to the thermal subsidies granted, with dissatisfied goals in respect with the resources granted, indirectly, and sectorized, and without adequate monitoring, and inspection. Moreover, it ensures this is added to problems resulting from public institution’s decentralization, the lack of focalization, and characterization of beneficiaries with territorial, and transversal relevance of energetic poverty.
Although there are norms, and laws, finally the recurring problem is who inspects, and enforces compliance, as an example, when low durability wood is used in Chile, it is required to use wood treated with preservatives authorized, and registered in SAG (Agricultural and Livestock Service) in accordance with the risk level in benefit of the structure [
20], it is a binding norm of the OGUC (General Construction and Urbanism Ordinance) [
21]
. Thus, buildings with wooden framework, and wooden prefabs mentioned in E, and H classes, must comply with the articles 5.6.8
1. of this ordinance. In the same way, pieces or elements of wood, whether structural or finishings, with structural graded or not containing other construction classes, must comply with 5.6.6. and 5.6.8. of this ordinance [
21]
. By observing the supply, it shows that this is a complex scenario to address, since preserved wood tends to be higher in price, 15% more than without treatment, home buyers do not analyze or know the consequences of not including this expense, they rather save on costs, but not due to the usage of chemical compounds, or the preference of protection over design, but for not having a real durability understanding. Without reasoning that, while the initial expense is a little higher in materials, the proportion of total cost of a house ready to be inhabited is practically residual, (it does not exceed 1 to 3%, the same case is observed in relation to thermal isolation, and floor humidity isolation), and if they would have been contemplated, it would have led to an important progress in quality, durability, functioning, and performance of the house. Based on the life cycle logic, less forests would need to be cut to build, and/or to heat, there would be less transportation requirements, it would increase service life, decreasing the necessity of recycle, replace, reuse 3 to 4 times more than if wood was not preserved. It is possible that a better understanding by users would promote a better regulation compliance, through an informed acquisition.
Coincidentally, this study indicates that there is a strong fragmentation of companies offering “prefab houses” products, that is to say, they build components, and/or complete houses, but no installation of wet, and dry networks, neither installation service, and foundation ground enablement, and urbanization, and industries are not planned to complete this cycle. Thus, a favorable environment is created to pretend satisfying the needs of those who seek options to solve their housing problems in a market with several offers. From prestigious, old, and established companies have shown their permanence in the market, and they have been prejudiced by the uncontrollable formal, and informal companies with no legal compliance with buyers, for example the thermal comfort norm, therefore this study supports what is informed by [
19] in their findings.
By exposing and describing this industry, the existent productive capacity can be explained, making adequations to comply with regulations, strengthen users, and whatever is necessary to make this productive sector a more integrated one, successful, and useful for society. In order to do this, as indicated [
22], “the extent, and gravity of energetic poverty are deeply connected to the thermal industry, and the inefficiency of houses built, although not generalized, there is a negative component of the market when assuming mistakenly that costs are being reduced by not including thermal comfort, when in reality is the other way round. The base of the existent investigation, according to [
22], it has been limited to the identification of real behavior, building technology, and design factors that influence in thermal comfort, and fuel consumption in homes. It was perceived the necessity of take action from the regulatory sector, as well as in the user’s empowerment to fulfill their rights, and to have access to efficient, and calculated solutions designed by experts.
This investigation allows to reflect on the necessity to achieve progress against the reality that demonstrate that the state’s reaction to promote changes is going at a much lower speed than the settlement of families in the territory, and there is more asynchrony between necessity, and the state’s rhythms [
23,
24]. According to the national cadaster on camps [
24], there are 76.544 families living in precarious settlements, 64% more than in the 2019 cadaster, the self-building or the acquisition of emergency houses exacerbates the problem, not only due to the exposed energetic poverty, but by the consequences of exposition, and physical insecurity. Each economic, and politic crisis, or any important disaster in the country leaves a lost of economic power, and houses, increasing the housing deficit, worsening by the increase of house prices, pandemic, migratory flow, and fragmentation of homes. It is not about decreasing the housing deficit, but to increase law enforcement, or at least more than it is currently available.
The analysis on used housing addressed in [
25] for 68.466 houses, all of them located in all regions of the country with data provided by the survey Casen in 2017, indicates that 38.1% are built out of wood. The study show that the wooden house is always in a lower quality position when observing size ranges, which increase in houses with sizes lower than 40 m
2, where the majority are structural of wood. Another important factor is that, for each 100 wooden houses in the country, 23 have less 40 m
2, while in concrete, and brick it reaches 12 to 13 units, respectively, which is directly related to the poverty level of families, and the size of the house.
Finally, it is concerning that, in overall, the safety subject has not been analyzed as a relevant topic until now, and that is still not enough considering sustainability, exemplified through the life cycle analysis, also to get clarity in respect of the final destination of building materials, which is the subject where wood have advantages, but in a still little sophisticated market of prefab houses, these are not shown as an attribute yet. For that reason, it is suggested to consider these three vital elements in construction with wood: Reduce – Reuse – Recycle (R-R-R).
5. Conclusions
This industry is characterized by providing houses in Kit mode to build, already built, and turnkey to a lesser extent, thus being confined to construction factories, in addition to housing companies, both participate in providing housing solutions, so they should be regulated by the state.
Most of the companies are located in the Metropolitan region with 69%, followed by Valparaíso region with 20%, and finally the O’Higgins region with 11%. The type of company that predominates is constructor-manufacturer with 80%. In terms of formality, 83% of the companies are formal, and 17% informal. This information should be related to the high number of people living in these regions.
A 54% has a low complexity, 35% medium-level, and 11% of high complexity, which makes evident the companies’ level of preparation to face markets with higher compliance requirements, technical criteria, deadlines, and costs.
The global evaluation of the 88 companies indicated that 2.7% obtained level 1, 37.5% obtained level 2, and 58.6% level 3, and only 1.1% was located in a level 4, none of them obtained the level 5.