Keywords:: design phase defect cost management optimization measures

Abstract: Cost management is the core content of the project. Based on the author's working experience, the paper analyzes the shortcomings of cost management in the design stage of landscape engineering, and puts forward the optimization measures of cost management in each stage of landscape engineering, which can provide some reference for the cost management of landscape engineering.

1. Introduction

Landscape engineering refers to the ancillary works of outdoor buildings, pursuing the artistic beauty of the overall landscape and local landscaping. The implementation targets include exhibition halls, roads, drainage, lighting control and other supporting projects, as well as landscaping projects such as rare flowers, trees and living plants. It has many engineering contents, small dispersion scale, many kinds of materials, difficult management, great price change, long maintenance and management cycle of living workshop, wide engineering coverage and difficult cost management. In recent years, the number of national and provincial landscape engineering projects has been increasing, and the investment cost of landscape engineering has also been increasing. Therefore, it is of great practical significance to implement effective management of landscape engineering cost.

2. Lack of cost management in the current landscape design stage.

The (1) design is arbitrary.

Landscape engineering should embody naturalness and artistry. In the process of landscape design, in order to achieve the ideal design goal, the original design is often changed greatly in the design process, which has a certain impact on the project cost management. As shown in table 1, after the design data of the greening project of the central square of a certain unit was changed, the increased direct cost reached19.150,000 yuan, accounting for18.11%of the total increase; Plus management fees, handling fees, taxes and other expenses, accounting for about 23% of the total increase.

(2) the design depth is not enough

Insufficient design depth is the biggest problem in landscape engineering design. Most landscape engineering designers only pay attention to the design of renderings, and have not conducted in-depth design and research on them. For example, some garden engineering construction drawings are not marked with elevation, which leads to the uncertainty of earthwork excavation during construction and becomes the gap of project cost growth; In addition, designers do not go deep into the site and only rely on subjective imagination to carry out engineering design, which leads to inaccurate design parameters and great differences between design projects and actual projects. For example, the tender budget for the greening project of the central square of a certain unit is 3105800 yuan, and the total amount of work increased due to design changes reaches 226370 yuan (Table 2), accounting for 13.72% of the tender budget.

(3) The overall quality of landscape architects is low.

Compared with industrial and civil construction projects, the design of landscape engineering is relatively simple, and the unreasonable and limited professional knowledge structure of landscape designers is one of the main reasons for the uneven design level of landscape engineering at present. Landscape architects are only good at the design of gardens, horticulture and environmental art, and pay attention to the performance effect of drawing design. However, they lack certain construction knowledge and pay little attention to the structural performance and hydropower design of landscape engineering, which has a great impact on the project cost.

For example, in the outdoor environmental engineering of a school veterinary hospital in a certain unit, the designer's design standard for the garden road is to design according to the conventional road base mode, that is, after the base is compacted, the stone chip cushion is 300mm, the stone chip cushion is C 15 concrete cushion 100mm, and then colored bricks are laid, which leads to an increase in cost items. In addition, the landscape designer didn't set up circuits, lamps and other facilities reasonably in the early design process, which had a great influence on the final cost.

3. Optimization measures of cost management in each stage

3. 1 design stage

(1) Conduct design bidding and optimize the design scheme.

The introduction of landscape engineering design bidding has pushed the competition mechanism to the forefront of engineering projects. Excellent garden design scheme can not only be pleasing to the eye, but also reflect the economy and rationality. Through bidding, selecting excellent design scheme and design unit can ensure the advanced nature and economy of design.

(2) Implement quota design and control design cost.

Landscape engineering has certain artistic characteristics, diverse forms of expression and different standards, which leads to great changes in the selection and use of materials and the free space required by technology. It is suggested that quota design should be implemented, that is, the construction drawing design budget should be controlled within the total budget estimate, and the investment and engineering quantity should be decomposed into various disciplines, and then into each unit project and each branch project to realize the control and management of investment quota. At the same time, it can also effectively control the design standard, engineering quantity and budgetary estimate index.

3.3 Bidding Stage

Like other construction projects, the valuation of garden engineering cost also has the characteristics of multiple. The cost management of construction bidding stage, design stage and construction stage is the key stage of the expected "reasonable price" of the project.

(1) Prepare bidding documents suitable for landscape engineering.

As a programmatic document in the bidding process and even the project implementation process, the bidding document is the key to the whole project cost management. The bidding documents shall be forward-looking and unchangeable. Forward-looking, that is, to limit and explain the parts that may change the engineering quantity in the future, and to clarify the allowable adjustment range of the engineering quantity change range for the work that is easy to cause the engineering quantity change, such as earthwork and slope modeling in landscape engineering; Invariance, that is, when determining the project cost and related expenses, the provisional amount should be reduced as much as possible.

(2) Pre-qualification before bidding.

Within the scope of meeting the project qualification requirements, optimize the construction unit, and focus on the credit, strength and performance of the bidding construction unit. On-the-spot investigation of construction units that meet the preliminary examination conditions can also play a certain role in curbing the bidding.

3.4 Construction stage

The construction stage belongs to the stage of large-scale capital investment. The characteristics of landscape engineering emphasize naturalness and artistry. If there are many uncertainties, the investment will be out of control, far exceeding the expected target cost.

(1) Construction contract is an objective document of cost management.

The construction contract is the basic basis for the whole construction stage, and it is a document that both parties clearly stipulate their respective responsibilities, rights and interests and are protected by law. In the contract of landscape engineering, besides the total project price, material supply, visa change management, project price payment and completion settlement, the engineering quantity should also be confirmed. Generally, the fixed-rate pricing model is adopted for garden projects, and the unit price risk is borne by Party A and the quantity risk is borne by Party B. Therefore, the scope of the project must be agreed, and it is clear that there is no change in the engineering quantity within the scope of work.

(2) On-site visa is the key to the project cost.

On-site visa project is called engineering change in cost theory and belongs to on-site economic and technical visa. It is the written record basis for the change and settlement adjustment of the construction content outside the contract, the focus of cost management in the construction stage, and the key factor affecting the project cost. Because the on-site visa of landscape engineering is inevitable, it is very important to handle the on-site visa correctly.

(1), define the characteristics of the on-site visa. There are some unstable and unpredictable factors in on-site visa, and it is beneficial to the whole construction process to clarify the characteristics of on-site visa in the process of garden construction. For example, in the central square project of a unit, the construction unit quoted the price according to the on-site mixing concrete when bidding, but in the implementation, it was required to change the concrete into commercial concrete on the grounds that the site was located in the central area, which affected the students' class. When bidding, the cost of tree survival and shade shed was not considered, and the construction cost was increased at will. Therefore, as long as we grasp the concept and significance of on-site visa, we can avoid the occurrence of unreasonable visa and control the cost.

② Grasp the accuracy of on-site visa. Be a gardener

In the process, the on-site visa involves earthwork. According to the different soil quality, earthwork transportation distance, engineering vehicle selection and required price, the soil type and the proportion of each type of earthwork are clearly indicated in the visa form, and the transportation distance and vehicle type are clearly defined.

3.5 Completion settlement stage

The settlement of garden project completion means that the construction unit completes all the specified work contents according to the contract requirements and makes the final settlement of the project price to Party A, which is the last important link of the whole project cost management and also the link that truly reflects the project cost. How to grasp this link, we must do the following four aspects.

(1) Verify that the settlement content should comply with the bidding documents and contract terms.

Generally, the contract price plus the cost of design change and on-site visa is adopted for landscape engineering. This requires that the work content in the contract must be distinguished from the added project content. Content should not be added to the contract at will.

(2) Verify the change visa form

Whether the visa change is correct is an important work in the construction stage. In addition, only the visa form with complete procedures can be done.

(3) Audit of engineering content and quantity calculation

Under the current landscape engineering contracting mode, it is necessary to determine whether the contract content has been completed first, and then verify the additional parts in the contract. The greening part of landscape engineering is the key point of verification, such as whether the reported tree species, diameter and crown width conform to the actual situation; Whether the reported hedging density is true, etc.

(4) Review the quota and charge.

The landscape engineering adopts the quota pricing model, and the quota unit price is the mandatory index of the labor, materials and machinery expenses consumed by the quota subtitle. Check whether there is a wrong set or a high set of directly applied quota Buddhism; In order to switch operators, check calculation should be strengthened. The charging standard for the additional part outside the contract is mainly to check whether it meets the requirements of the contract.

summary

In order to effectively manage the cost of landscape engineering, the investment decision in the early stage of construction and the cost in the design stage should be taken as the management focus. In particular, we should grasp the key stage of design and achieve twice the result with half the effort. Only in each stage of project construction, scientific valuation methods and practical valuation basis are adopted to reasonably determine investment estimation, preliminary design estimation and construction drawing budget, can the investment benefit be finally improved and the ideal effect be achieved.

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