The construction sector has noticeably evolved during the last 10 years, especially due to the introduction of new techniques of construction that use industrialised processes such as precast concrete elements. The consequence of such innovations is a drastic evolution in performance, characteristics and functionalities of new generation construction works.
Society keeps on changing faster. People’s social, economic and environmental needs have also changed quite significantly during the last ten years (average age of people has increased, energy prices grown, awareness of environmental impacts amplified).
Thanks to these innovations in construction, rebuilding has become a real alternative when considering renovations, instead of the traditional refurbishment. The possibilities given by new flexible designs adapt easily to the new needs of a changing society and are far better than having to reach a forced “compromise” due to the presence of constraints linked to the existing work.
ADVANTAGES OF REBUILDING
- Getting a real solution, not a mere band-aid
– Energy efficiency: a building can only be energy efficient when a combination of important factors like thermal mass, air tightness and ventilation are properly addressed. Energy Efficiency is not only linked to insulation, which is what is added in the renovation of an existing building. Realistically, all these aspects can only be fully tackled in a new building. A proper thermal performance benefits the environment and brings lower costs to the consumer.
– Improving internal comfort: refurbishment operations addressed to improve the comfort of a building are often limited to its external envelope (insulation, windows …), whilst the internal thermal and acoustic comfort are usually not considered or changed. In a new building all these aspects are taken into account, improving the total welfare of the users
– Stricter standards that provide healthier environments: today’s buildings are designed to follow stricter rules in terms of health and safety of the occupants, both from a material and a design point of view. This does not apply to old or renewed buildings. Therefore the consumer spends money only on the surface but continues to live in the same conditions as before.
– Improved fire safety: modern conceptions of fire safety (e.g. reliable escape routes) are already integrated in a new design.
Starting a new project is the best way to avoid possible hidden problems: technical, legal or other surprises (termites, fungi) that can be present and must be dealt with in existing works.
2. Improving social integration: After demolishing one or more buildings, the entire area can be designed to fit the present needs of people living there and improve their quality of life. Entire suburban areas can then be designed to include other commodities (like schools, hospitals, shops, recreation centres) whilst keeping a similar number of living units. This would finally improve social integration and add value to the land.
3. Taking advantage of modern technologies and systems: modern buildings can be designed with embedded systems of water handling (water tanks, wastewater treatment) and with heating and cooling ensuring better environmental performance. There are also new systems that improve accessibility to the building by facilitating the access of elders and disabled people. All these systems are very easy to install when these elements are included in the initial design, but very difficult and costly in a refurbishment operation.
4. Getting the most cost-effective solution for the long term: One considers renovations because one wants to keep on using the building for as long as possible. But it is important to take a longer term point of view. Even though rebuilding costs maybe higher at the beginning, the investment is soon recovered by a lower running cost of the building. Moreover, when it is a low energy or “zero energy” building, these saving allow a break-even in the overall project costs on a long term perspective
5. Increasing competitiveness through innovation in sustainable construction: the “lead market initiative” identified sustainable construction as one of the lead markets for strengthening the European competitiveness in a knowledge-based economy. New buildings are more adapted to include these principles in their design than refurbishing the existing ones.
The choice of a rebuilding activity should be based on detailed consideration of the main drivers of choice:
- 1. Good time for rebuilding
– Can I afford a limited period of inoccupation? Acquiring a building is the best occasion for thinking about a rebuilding operation. Living in the midst of renovations is well known to be a dramatic experience. Of course, the operation is also easier when addressing to second houses
– Was the building abandoned or the structure not used? Abandoned buildings are more vulnerable to the proliferation of hidden problems and problems could easily arise shortly after the end of the refurbishing process. Stability and functionality could also be jeopardised by bad maintenance and the effects of improper use
- 2. Quantifiable parameters to be taken into account
– When does the building have to be ready? Thanks to the industrialised process of precast concrete elements, the construction work is fully planned ahead of time, including the delivery date of the finished building. In addition, by using these elements as both structural and non-structural building envelop, the overall rebuilding time is dramatically reduced.
– Will I spend a lot in energy? An energy audit should be made on the existing building and on the new one in order to compare the expected running costs for the two solutions. The expected savings should be deducted from the initial cost in order to assess the real costs of the rebuilding operation
– Did I assess the environmental impact? Do not overlook the fact that structures always have an environmental impact and that society is also increasing its environmental awareness. Therefore, the most efficient option must be chosen to offer to the users buildings with the best environmental performance possible. This could be taken into account in the decision process with a weight that depends on the sensibility of the owner.
– Be careful with the presence of dangerous substances. Whether dangerous substances like asbestos are detected in the existing building, the removal procedures can be very long and costly.
– How long it will take to get return to your investment? If the objective is to profit from the structure or work for a longer time, the most favourable choice is rebuilding. In terms of overall costs, this can be more economic than several refurbishment operations.
– What would be the advantage of increasing the usable space? Increasing the total height and/or decreasing each floor’s height would allow to better use the available land and improve the final value within the same boundaries.
- 3. Non-quantifiable parameters to be taken into account
– Which cultural heritage do I want to preserve? On one hand, the natural and cultural heritage of the community affected by the construction work must be respected and preserved. Rebuilding activities with precast concrete allows either the conservation of the outside shell with a completely new internal design or the faithful reproduction of the existing style.
– Which modification of the landscape is required? On the other hand, some areas have been critically disfigured by unwise choices in the past. In this case, the rebuilding option allows a completely new approach that respects the natural environment.
Rebuilding is a real alternative: following the needs of the user and his sensitivity to the above mentioned advantages and drivers, the rebuilding alternative is more valuable than the refurbishing one for social, economic and environmental reasons.
Society requires public support: For all the above mentioned reasons public administration is expected to support the rebuilding and renewing of the infrastructure stock by offering fiscal incentives and other stimulus to encourage this activity given that it constitutes global welfare for our society.