Selective Demolition of a Family House from an Economic Perspective in Practice ^†

Abstract

This article discusses the selective demolition of a family house in Ostrava Hošťálkovice carried out by the construction company Tomáš STRAUB s.r.o. This selective demolition of the building was carried out in order to map the economic impact of selective demolition and the subsequent recycling process of the waste obtained in normal construction practice. The aim of the article is to familiarize readers with the economic impact of selective demolition and its influence on the method of execution, including the economic motivation of the execution subjects. At the same time, the article also compares the economic impact in other regions of the Czech Republic based on the input data obtained.

1. Introduction

Recycling is currently considered the only sustainable activity that generally reduces the burden on the environment. Today, almost any raw material can be recycled.

Recycling construction and demolition waste (CDW) is currently considered to be one of the key ways to fulfill the principles of sustainable development and the circular economy in the construction industry. According to Coelho [1], selective demolition is a fundamental prerequisite for high-quality recycling, as it enables the separate collection of individual fractions and their subsequent use. However, the economic efficiency of this approach remains questionable, especially in everyday construction practice.

Research shows that CDW recycling yields significantly different results in different regions. For example, Soto-Paz [2] reports that the recycling rate globally ranges from 7% to over 90%, with an average of around 35% of CDW still being landfilled. Christensen [3] emphasizes that the introduction of closed material cycles requires systematic involvement of all participants in the construction process, including investors, the implementing company, and recycling centers.

From an economic point of view, selective demolition is often perceived as a more costly option than the conventional methods. However, according to Pantini [4], it is not possible to evaluate its benefits solely from the perspective of the direct costs; it is also necessary to take into account the broader environmental and socio-economic impacts. These facts are also confirmed by Caro [5], who points to the high potential of recycled materials, especially in the area of concrete mixtures and, on the other hand, stresses the limited utilization of recycled bricks.

The current trend is focused on greater integration of circular economy principles into construction project management [6]. This means not only legislative pressure for higher recycling rates (e.g., the Waste Act in the Czech Republic), but also the search for practical and economically sustainable solutions. Bonifazi [7] states that technical limitations, high sorting costs, and insufficient market demand for recycled materials are among the most significant obstacles to wider application of this approach.

The aim of this article is therefore to analyze the selective demolition of a family house from the perspective of its economic efficiency. Based on a case study from Ostrava-Hošťálkovice, the economic impact of two different approaches is examined: recycling construction and demolition waste in-house and handing the waste over to an authorized person.

2. Description of the Approach to Waste Generated by Construction Activities

Every construction project has waste disposal costs in its budget. Waste is produced during the actual construction in the form of demolition and dismantling work. Other waste generated includes packaging and leftover building materials used during the construction. Waste is therefore generated during every construction project, and its valuation is an integral part of the cost balance sheet of every budget.

How are the quantity and types of waste determined in the preparatory phase? The type and volume of waste are determined by the project designer, who assesses the type and quantity of construction waste in the summary technical reports. This part of the technical reports is often significantly simplified, and the amount of waste is roughly estimated. A more precise definition of waste in construction projects and activities in general is then created during the budgeting process. Each item has its own links to waste removal and disposal. The budget planner’s work involves specifying the volume and type of waste. At the same time, it is necessary to consider the location of waste disposal or recycling facilities and the costs of transport.

2.1. Construction and Demolition Waste and Building Valuation

From the perspective of building valuation, however, the waste disposal item is often difficult to estimate for several reasons:

• The amount of waste in budgets is often a figure based on the dismantling weights of the item. The method of calculating dismantling weights has a significant impact on the final value. The reality is often very different.
• Categorization of the expected type of waste, definition of the required budget item, etc. In general, some waste catalog numbers are grouped into larger units.
• The price for waste disposal is often difficult to predict from the perspective of the total bid price for the construction work. When valuing these items related to waste transfer and disposal, they are commonly treated as “superfluous” items that increase the total bid price of the construction work. It is common budgeting practice to deliberately undervalue these waste-related items in order to achieve a lower price for the work.
• Waste disposal also involves transportation costs, vehicle dimensions, volume, permitted weight, distance to the nearest landfill, recycling center, etc.
• The focus of all construction projects is the construction or renovation itself, and the investor always focuses on this part as much as possible, but waste disposal is an essential and often neglected part of the process. Given that public procurement tenders usually have clear rules, namely the lowest total price of the work, most planners and budget planners ask themselves how to deal with the above facts in construction tenders so that the total price is competitive.

2.2. Construction and Demolition Waste from the Perspective of the Waste Act

The Waste Act no. 541/2020 Coll. [8] clearly states that “§ 15 par. (2) The waste producer is obliged: part f) when removing, constructing or maintaining a building, to follow the procedure for handling demolished building materials intended for reuse, by-products, and construction and demolition waste in such a way as to ensure the highest possible degree of reuse and recycling.”

Is it therefore possible to comply with the letter of the law, behave responsibly, and at the same time be competitive in obtaining construction contracts? Practice so far clearly leans towards a negative answer. This is a fact for the following reasons:

• The price for dismantling work would have to be determined, including the basic sorting of the demolished structure, i.e., higher costs for machinery and operators, extension of the duration of the work, supervision of the sorting itself, etc.
• There must be sufficient space on the construction site for the storage of individual types of waste, i.e., higher costs for construction site arrangement, extension of the duration of the work, and inspection activities.
• Transportation of individual types of construction and demolition waste (CDW), i.e., higher costs for transportation and handling within the construction site.
• Transportation of individual types of CDW, i.e., higher costs for transportation and handling of sorted raw materials.
• Handling and preparation of CDW at the construction yard => higher costs for mechanization and transport within the construction yard.
• Transport of sorted waste for disposal and recycling.
• Fee for disposal or recycling according to individual types of waste.

The reality and the list of reasons stated above cause most construction companies to try to get rid of demolition waste in the easiest and cheapest way possible. The absence of economic motivation to send clean and sorted waste to recycling centers means that the responsibility is shifted to recycling centers and landfills, which often do not have the ability to use the waste effectively.

The only exception is construction activities where only one type of waste is generated during demolition. Examples include the reconstruction of transport structures—replacement of the asphalt layer, structures that can be dismantled, or structures made only of specific materials, such as clean concrete or reinforced concrete, asphalt, or wood.

3. Description of the Demolished Building

The selective demolition of a family house in Ostrava is an example of economic consideration of waste and its disposal. This selective demolition was carried out by the construction company Tomáš STRAUB s.r.o. This is a regional construction company with many years of experience in construction, reconstruction, remediation, etc. The company has its own equipment for demolishing buildings, personnel, and machines for processing construction and demolition waste (impact crusher and sorting machine).

The controlled demolition of the family house was carried out 7.5 km from the contractor’s construction yard; see Figure 1.

Simple project documentation for demolition work was used as the basis for the actual demolition. The documentation contained only an approximate composition of the family house structure without the expected amount of CDW. The documentation for demolition work was approved by the local building authority.

Before the work began, a check had been carried out to ensure compliance with the construction documentation; however, it only distinguished the material composition in general terms. It was therefore necessary to determine the method of selective demolition so that it corresponded to the approved budget. An estimate of the type and quantity of construction and demolition waste was made, which is shown in

Table 1. Estimate of the type and quantity of construction and demolition waste.

Construction Type	Waste—Cat. No.	Name of Waste	Volume in m3 Amount m2	Disposal Method
Roof covering	170103	Tiles and ceramic products	280 m2	Landfill disposal
Perimeter walls	170107	Mixtures or separate fractions of concrete, bricks, tiles, and ceramic products not listed under number 17 01 06	230 m3	Landfill disposal
Concrete structures, staircases, foundations	170101	Concrete	36 m3	Recycling
Metals	1704xx	Metals (including their alloys)	5 t	Recycling
Wood	170201	Wood	0.5 t	Landfill disposal
Glass	170202	Glass		Recycling
Other municipal waste	200301	Mixed communal waste		Landfill disposal

.

In this particular case, the selective demolition was carried out in two stages, with and without mechanization. All workers and machine operators present were informed of the intention to carefully separate large quantities of concrete and construction and demolition waste, but within budgetary limits. The prerequisite for producing a high-quality product from recycled materials is its purity. In the case of selective demolition, an impact crusher operator was present to check the quality.

3.1. Stage No. 1—Dismantling Without the Use of Machinery, Manually

As part of the dismantling process without the use of machinery, the selective demolition procedure was as follows:

• Clearing out the building—furnishings, sanitary ware, carpets, linoleum, small carpentry elements (cabinets, shelves, etc.).
• Removal of windows and doors—windows, doors, removal of interior wooden door frames, door wings.
• Removal of roofing—ceramic tiles.
• Dismantling of wooden roof trusses.
• Removal of metal flashing—window sills, gutters, drainpipes, etc.

Standard hand tools were used for the dismantling work. The work was carried out exclusively by construction workers. During the dismantling, the individual raw materials were separated into the following:

• Wood—left on the investor’s property for possible resale as firewood (roof trusses, floor coverings).
• Metal—door frames, window sills, roof flashing, railings—left on the investor’s property, intended for sale at a scrap yard.
• Glass—glass blocks, unsorted, minimal quantity.
• Mixed municipal waste—due to the long-term deterioration of the building, it was not possible to further sort the remaining waste. This generally consisted of carpets, plastics, rotten or painted wood, mattresses, cabinets, food leftovers (basement), etc.

At the end of stage 1, the building was ready for demolition. Wall system, ceiling structure, and foundation structure.

3.2. Stage No. 2—Demolition of the Building Using Machinery

Figure 2 shows a view of the building designated for demolition. The demolition of the building using mechanization was carried out according to the following procedure:

• Demolition of wall systems—brick, plaster, ceramic tiles.
• Demolition of ceiling structures—concrete, steel structures.
• Demolition of foundation structures—brick, concrete, stone.

Maximum use of mixed demolition waste and concrete for further recycling was considered at this stage of the demolition. In the case of wall systems and ceiling structures, maximum sorting of rubble into mixed demolition waste and concrete was achieved. In the case of foundation structures, it was found that they consisted of a combination of brick foundation masonry, concrete, and stone foundations. The foundation structures were not sorted in any way. During the demolition, the foundation structures were covered with rubble, and during the gradual extraction of the rubble, it was not possible to effectively separate the foundation structure from the adjacent soil. Brick and concrete rubble and other foreign elements, such as bitumen roofing felt, became mixed together (see Figure 3).

The sorting of individual types of waste took place directly at the demolition site. Construction and demolition waste with a higher proportion of brick and concrete was transported and deposited separately at the crushing site—the construction yard of Tomáš STRAUB s.r.o. Company. Other raw materials intended for further processing, such as wood, were stored on the investor’s property. Unsorted waste or waste that was difficult to sort was stored and transported to the SOMA Markvartovice landfill.

The transport distances between the construction site, the recycling site, and the landfill were approximately the same. The distance between the demolition site and the construction yard was 7.5 km (see Figure 1). The distance between the landfill and the demolished building was 8.4 km.

4. Economic Balance Sheet

4.1. Selective Demolition with Storage in an Intermediate Dumping Site and In-House Waste Processing for the Purpose of Generating Revenue from Sales

This chapter quantifies the costs associated with the selective demolition of the building and the subsequent transfer of waste for storage or recycling. For the purpose of cost assessment, the entire course of work was recorded and the costs are described in the tables below. Waste that was transferred for recycling was deposited at the premises of Tomáš STRAUB Company, where it was subsequently crushed. Other waste materials that could not be further recycled were transferred for disposal.

An overview of the costs of clearing the building, dismantling the roof structure, trusses, floors, demolition of the building itself, transport, and storage of rubble at a dumping site or collection point is provided in

Table 2. Total cost of demolition of the building, including preparatory work.

Selective Demolition FH	Worker Hours/h	Engine Hours/Mh	Load/t	Total Distance/km	Fuel/L	Price/Unit/Euro	Total/Euro	Depreciation (20% of Operating Costs)
Wheel excavator CAT M316D, demolition hammer, demolition shears		80			500	EUR 1.4	EUR 700	EUR 140
Truck, MAN 6 × 6, load capacity 12 t			789	951	520	EUR 1.4	EUR 728	EUR 145.60
Loader—Kramer 280		5			64	EUR 1.4	EUR 89.60	EUR 17.90
Machine operator—driver, loader	108					EUR 14.0	EUR 1512
Machine operator—excavator	117					EUR 14.0	EUR 1638
Unskilled laborer	234					EUR 10.0	EUR 2340
	TOTAL COSTS INCLUDING DEPRECIATION					EUR 7311.1

. The selective demolition was carried out by a total of five ground workers, using a wheel excavator, a front loader, and a truck. All the machines were operated by two machine operators. The price level corresponds to the period in which the demolition was carried out, namely December 2023.

The volume of consumption was determined:

• Worker, machine operators—determined based on actual hours worked, according to payroll;
• Wheel excavator, loader—determined based on machine operating logs—number of engine hours, fuel consumption;
• Truck—determined based on electronic logbook;
• Crusher—determined based on integrated scales and machine operating log.

Table 3. Overview of volumes of individual types of waste, including landfill fees.

Selective Demolition Output	Unit	Recycling	Dumping Site Disposal	Landfill Disposal	Landfill Fee in EUR/t	Total Costs
Mixtures or separate fractions of concrete, bricks, tiles, and ceramic products not listed under 17 01 06 (170107) with a higher brick content	T	406	406			EUR
Concrete (170101)	T	95	95			EUR
Costs associated with handling at intermediate dumping site						EUR 1002
Wood (170201)	m3		9			EUR
Mixtures or separate fractions of concrete, bricks, tiles, and ceramic products not listed under 17 01 06 (170107)	T			274	EUR 15.8	EUR 4329.2
Mixed construction and demolition waste (170904)	T			5	EUR 95.2	EUR 476
	TOTAL COSTS FOR LANDFILL DISPOSAL					EUR 5807.20

shows the volumes of waste collected and the costs of storage. Transport and handling costs are not included here. These costs are included in Table 2. Recycling was carried out at an intermediate dumping site on the premises of Tomáš STRAUB Company; see transport distance in Figure 1.

The prices set for waste storage are determined by local waste processing facilities, namely Ridera bohemia a.s. (Ostrava Mariánské Hory recycling center) and SOMA Markvartovice a.s. (MARIUS PEDERSEN).

Table 4 provides an overview of the total costs associated with crushing and handling the input raw material and output product. The crushing took place on the company’s premises, where both the input raw materials and the product itself were deposited. The impact crusher was chosen for the following reasons:

• Availability of the machine during the period when the crushing was considered.
• In the case of concrete recycling, a more suitable grain size of the recycled material is achieved on the impact crusher, e.g., shape index.

An impact crusher is generally suitable for processing waste with a lower degree of fragmentation. The preparation of the input material before crushing significantly affects the final product. The lumpiness of the input material has a significant impact on the quality of the output product, as does contamination of the input material with, for example, wood, plastics, or steel that could not be separated during the crushing process.

Table 4. Costs of crushing brick and concrete rubble.

Preparation for Crushing, the Crushing Process Itself, etc.	Worker Hours/h	Engine Hours/Mh	Load/t	Total Distance/km	Fuel/L	Price/Unit/Euro	Total	Depreciation 20% of Operating Costs	Notes
Impact crusher CH2/2		10	501			4 EUR	2004 EUR
Loader—XCMG ZL 30 G		12			144	1.4 EUR	207.4 EUR	41.5 EUR
Wheel excavator CAT M316D, demolition hammer, demolition shears		12			75	1.4 EUR	105 EUR	21 EUR
Machine operator—excavator	14					14 EUR	196 EUR
Machine operator—loader	14					14 EUR	196 EUR
				TOTAL COSTS			2770.9 EUR
Recalculation of costs for processing 1 ton of waste: 5.5 EUR/t

Table 4. Costs of crushing brick and concrete rubble.

Preparation for Crushing, the Crushing Process Itself, etc.	Worker Hours/h	Engine Hours/Mh	Load/t	Total Distance/km	Fuel/L	Price/Unit/Euro	Total	Depreciation 20% of Operating Costs	Notes
Impact crusher CH2/2		10	501			4 EUR	2004 EUR
Loader—XCMG ZL 30 G		12			144	1.4 EUR	207.4 EUR	41.5 EUR
Wheel excavator CAT M316D, demolition hammer, demolition shears		12			75	1.4 EUR	105 EUR	21 EUR
Machine operator—excavator	14					14 EUR	196 EUR
Machine operator—loader	14					14 EUR	196 EUR
				TOTAL COSTS			2770.9 EUR
Recalculation of costs for processing 1 ton of waste: 5.5 EUR/t

The total cost of demolition with partial dismantling of the building, transport of waste to an intermediate dumping site, landfill, and subsequent crushing of brick waste and concrete is 15,818.8 EUR excluding VAT.

The secondary raw material created by the transformation of waste (mixed construction and demolition waste and concrete) becomes a saleable commodity. However, the utilization of recycled concrete is relatively very broad. Recycled concrete is in demand as a substitute for natural aggregate.

In the case of recycled bricks, their utilization is very difficult. They can be used as a stabilizing layer or as backfill for landscaping.

Table 5. Expected revenues from sale.

Name	Unit of Meas.	Quant.	Price/Unit of Measure	Total Price
Brick rubble 0/16	t	406	2 EUR	812 EUR
Recycled concrete	t	95	6 EUR	570 EUR
TOTAL				1382 EUR

shows the potential revenue from the sale of processed waste.

4.2. Selective Demolition with Disposal at a Landfill or Transfer to an Authorized Person

In the next phase of the selective demolition of the family house in Ostrava-Hošťálkovice, we attempted to compare the costs of storing waste and rubble at collection points or recycling yards. Our aim was to compare the costs of storage and transport to a recycling yard located 9 km away from the construction site. It was the recycling yard of Ridera bohemia a.s. company. The costs associated with storing rubble for recycling at the recycling center are shown in

Table 6. Costs of storing rubble for recycling at a recycling center.

Selective Demolition FH	Worker Hours/h	Engine Hours/Mh	Load/t	Total Distance/km	Fuel/L	Price/Unit/Euro	Total	Depreciation 20% of Operating Costs
Wheel excavator CAT M316D, demolition hammer, demolition shears		80			500	1.4 EUR	700 EUR	140 EUR
Truck, MAN 6x6, load capacity 12 t			789	1025	520	1.4 EUR	728 EUR	145.6 EUR
Loader—Kramer 280		5			64	1.4 EUR	89.6 EUR	17.9 EUR
Machine operator—driver, loader	125					14 EUR	1750 EUR
Machine operator—excavator	117					14 EUR	1638 EUR
Unskilled laborer	234					10 EUR	2340 EUR
TOTAL COSTS							7549.1 EUR

.

An overview of the costs associated with waste disposal fees is provided in

Table 7. Breakdown of waste disposal costs.

Selective Demolition Output	Unit	Recycling	Dumping Site Dispos.	Landfill Disposal	Landfill Fee in EUR/t	Total Costs
Mixtures or separate fractions of concrete, bricks, tiles, and ceramic products not listed under 17 01 06 (170107)	t			680	15.8 EUR	10,744 EUR
Concrete (170101)	t			95	3.2 EUR	304 EUR
Wood (170201)	m3		9		EUR	EUR
Mixed construction and demolition waste (170904)	t			5	95.2 EUR	476 EUR
TOTAL COSTS						11,524 EUR

.

The total cost of demolition and subsequent disposal of rubble at recycling centers without the recycling itself is estimated at 19,125.16 EUR excluding VAT.

4.3. Comparison of the Approaches—In-House Recycling and Handover to an Authorized Person

The aim of this article was to map the economic aspects of the selective demolition of a family house in Ostrava, which was located approximately halfway between the contractor’s dumping site and the recycling center.

Table 8. Overview of the total economic cost of selective demolition of a family house.

Total costs of selective demolition with in-house recycling	15,818.8 EUR exc. VAT
Estimated revenue from recycled materials	−1382 EUR exc. VAT
Total including estimated revenue	14,436.8 EUR exc. VAT
Note: Processing CDW within a single economic entity is cost-effective if a recycling yard is available or if recycling can be carried out directly on the construction site. In the case of concrete recycled material, effective crushing and sorting can achieve a very high purity of input material, which can be used to replace natural aggregate in fresh concrete. Possible risks arise from legislation relating to waste management, regular testing and analysis of CDW, etc.
Total costs of selective demolition with disposal at landfills and recycling yards	19,125.16 EUR exc. VAT
THE DIFFERENCE IN COSTS BETWEEN THE DIFFERENT APPROACHES TO THE ENTIRE RECYCLING PROCESS IN OUR SPECIFIC CASE IS 4688.4 EUR EXCLUDING VAT
RECALCULATION OF COSTS FOR PROCESSING 1 TON OF WASTE (total waste volume 789 tons)
Selective demolition with in-house recycling	20 EUR exc. VAT/t
Selective demolition with disposal at a landfill and recycling facilities	24.24 EUR exc. VAT/t

presents an overview of the total economic costs of the selective demolition of a family house at the end of its life cycle.

Table 8 shows that if construction companies have sufficient facilities for temporary waste storage, it is more beneficial to process construction and demolition waste in-house rather than handing it over to an authorized person, provided that the temporary dumping sites and recycling centers are located at similar distances.

Based on the recalculation of costs per 1 ton of waste, the difference in economic profitability of the in-house recycling model is 4.2 EUR excluding VAT/ton. The in-house recycling model is therefore based on the systematic storage and sorting of waste for subsequent recycling and treatment directly on the waste producer’s premises.

It can therefore be concluded that, from an economic point of view, it is more beneficial for the producer of construction and demolition waste to be able to prepare such conditions for recycling at their own construction yard. The estimated cost savings can be approximately 4.0 EUR excluding VAT/ton.

5. Conclusions

This article deals with the procedure used by the construction company Tomáš STRAUB s.r.o. during the selective demolition of a family house from two perspectives: in-house recycling to achieve profit from separated materials and, alternatively, handing them over to an authorized entity. The following can be stated:

• The possibility of storing construction and demolition waste varies greatly across the regions of the Czech Republic. This is due to both the availability of waste storage sites and the availability of recycling centers. The key factors are the cost of storing sorted construction and demolition waste and the transport distance.
• In the Moravian-Silesian Region, it is slightly more economically beneficial for construction companies to process sorted construction and demolition waste, provided they have their own dumping sites. The Moravian-Silesian Region has the lowest waste storage price.
• The economic impact of processing waste for the purpose of selling secondary products is higher in other regions of the Czech Republic.
• Due to the gradual reduction in landfilling, the reuse of construction and demolition waste will be desirable from the point of view of the unavailability of storage, as well as the economic burden or benefit for the building companies.