We are at your side from the planning phase to the completion phase. No matter whether it is a question of quotation costing, work preparation, the preparation of schedules, the monitoring of costs or the preparation or defence of supplements – we are your partner and develop tailor-made solutions according to your individual needs.

Subcontract and contract management is one of our core competencies. Here we are either active on the side of the client or the contractor in an advisory capacity or productively in your team. As experienced project managers, we ensure that your goals are achieved and risks are averted.

We are happy to support you in drafting contracts, in your correspondence with contractual partners, in important meetings and all other tasks. We identify deviations, changes in performance and prepare the necessary additional cost notifications and auditable supplements for the contractor.

On the client’s side, we check deviations from the construction TARGET, evaluate corresponding supplements and additional cost claims and ensure compliance with the project objectives.

In complex construction projects, there are a large number of interfaces between the individual trades that make the construction process susceptible to disruptions. At the same time, there are a large number of possible changes in quantities, construction design changes and supplementary services which must be drawn up by the contractor in a verifiable manner or checked by the client in a qualified manner.

We offer our services in the sense of a competent, goal-oriented and fair handling of all these issues.

Just ask us!

Supplementary causes

One of the two most common sources of unforeseen cost increases and supplementary claims is the building ground with all its “hidden” surprises and influencing factors (such as groundwater and slope water, erratic blocks, soil layers, etc.), which are not always fully captured even in close-meshed exploratory drilling, as well as the contractor’s immanent expectation of the ideal-efficient use of his resources, which can lead to horrendous additional cost claims in the event of any deviation from the optimum – in the context of the so-called Construction Disruption.

We will be pleased to show you how you can effectively counteract these risks and disputes by drafting contracts with foresight. Arrange a personal meeting with us.

Example subsoil risk

The relevance of a critical analysis of the contract contents becomes clear, among other things, in the subject of subsoil: Up to now, the contractor could assume that the builder-owner or client basically bears the subsoil risk. “Building land is a builder’s risk” is the relevant well-known saying. Accordingly, the BGH has stated: If subsoil expertise is enclosed with the invitation to tender for construction work, then its contents regularly become part of the contract. This shall apply in particular in the event that the contents of the subsoil expertise are significant for the Contractor’s performance and thus for the calculation of the performance.

The Munich Higher Regional Court, on the other hand, found that the contractor can also assume the subsoil risk. But only if the contractor, in the case of a situation which is manifestly and clearly unclear as to the conditions in the ground, has quoted a unit price for all types of soil and whose offer thus also covers the conceivable worst case
worst case
price-forming. This example shows that ultimately everything depends on the specific wording in the construction contract and that no customary rights can be derived.

Example of disturbed construction process

In order to assert a claim for additional costs arising from a disrupted construction process, the claimant must provide a comprehensive causal explanation of who caused the disruptions and what the actual consequences of these disruptions were for the actual construction process. This has been required by the now constant case law at the latest since the BGH decision of 24.02.2005 (VII ZR 141/03) in Germany and thus formulates relatively clearly its high formalistic requirements for the claimants concerned.

Similarly, we will assist you in the successful establishment of your claims and additional costs or, indeed, in the defence against claims made against you. Only with a determined examination of the contents and representations of a claimant can it be possible to reject unjustified claims or to reduce them to an appropriate level. Points of attack here can be, for example, the insufficient consideration of disruption factors from the risk sphere of the claimant, a missing or inadequate consideration of the ACTUAL process or an evaluation of the disruption consequences that is not clear-cut.

The complete proof of causality must take into account the failures of all project participants and be oriented to the actual process.

In Switzerland, on the other hand, it is interesting to note that until 2016 no dispute involving a “construction process disruption” ever made it to the highest judicial authority, the Federal Supreme Court in Lausanne, so that until a few years ago there was still some legal uncertainty on this issue and even today there is some room for interpretation and open questions in the form and validity of the formal “evidence”.

Evidence of «construction process disruption» - situation in Switzerland

Who is liable if, in the course of construction, delays occur in the execution planning by architects and specialist planners or in the necessary approvals by representatives of the client, the progress of construction stalls and the further planning and, in particular, construction work cannot be carried out at all or cannot be carried out on time? Disruptions to the construction process or interruptions to construction work in the meantime can have massive economic consequences.

Planners responsible for this have to reckon with liability consequences, above all with fee reductions and/or compensation consequences, insofar as they have not fulfilled their contract according to the rules of their professional art.

But what about the affected contractors, who have not concluded any contracts with the faulty planners, but who want to be held harmless by the client under a contract for work and services?

First, it should be noted that the acts or omissions of the design professionals retained by the builder shall be attributable to the builder-owner are to be credited. The planners, unlike subcontractors, are regarded as auxiliary persons of the owner in relation to the contractors.

Insofar as plans are delivered to the building contractors in a defective and delayed manner or if the individual contractors and suppliers are not coordinated by the construction management in a professional and timely manner, this shall constitute a
breach of cooperation
on the part of the client.

For such disruptions of the construction process, the Swiss Federal Supreme Court has ruled in a long-awaited “Leading Case” (4A_507/2015, judgment of 19.02.2016) that the affected fixed or lump sum price contractor – in addition to a reasonable claim for extension of the deadline for the completion of the construction (and, if applicable, a right to terminate the contract) – is entitled to additional compensation if additional expenses result. In the event of culpable conduct, damages may also be due under certain circumstances.

Such constellations with additional remuneration consequences at the expense of the client typically arise in the case of delayed provision of the building ground or the building object, non-compliance with the schedule, delayed delivery of plans and in the case of insufficient coordination of the planners or subcontractors.

The additional expenditure of the contractor in the event of disruptions to the construction process is reflected, for example, not least due to the extension of the construction period:

Prolonged provision of work equipment and construction site facilities

Additional personnel and material costs (delay costs, increased procurement costs)

Additional structural measures

Repair of damage to the structure

productivity losses (additional disability costs, rescheduling)

Acceleration measures (additional personnel to meet deadlines)

How the additional expenditure subject to remuneration (including a cost reduction obligation to be offset) is to be calculated and substantiated in concrete terms and according to which criteria the supplementary claim is to be determined are difficult, partly unresolved legal questions.

If the parties have not agreed on this, which is usually the case, it must be decided whether the concrete additional expenditure plus a surcharge for risk and profit is to be assumed (which should be the rule) or whether, alternatively, comparative prices are to be used in the sense of a “price update” in accordance with the concluded contract for work. The latter price link is found in principle in SIA standard 118.

What is clear, in any case, is that disruptions to the construction process are capable of fundamentally displacing the originally agreed price regulator for the construction of the building project, which can not only trigger disputes and litigation, but also jeopardise returns and the success of a construction project. The client, and under liability aspects also the responsible planners, suddenly risk having to bear claims in the amount of the actual (additional) expenditure caused, which is precisely what is to be prevented by the contract design.


The answer as to how construction disruptions and threatening additional remuneration consequences for the client or liability risks for the planners can be avoided is in itself simple: In addition to the clearest possible rules of the game (e.g. plan delivery programs, regulations for the quality and structure of the planning documents, information on the respective time requirements and the release regime), trusting cooperation and open communication between the client and the planners or construction managers are required, as well as expertise, sufficient manpower and commitment on the part of the parties commissioned with the implementation planning and construction management.

In individual cases, it is advisable to call in an advisor and trustee for the building owner to advise the building owner and to accompany and supervise the parties involved in the construction in this respect.

With our many years of experience in the field of supplementary services, we are happy to support you at all levels of this complex matter.

Evidence of «disruption of the construction process» - situation in Germany

Procedure for proving disruptions to the construction process based on current case law (BauR 2017, 178)

In recent years, there have been numerous landmark rulings in Germany on the requirements for proof of construction disruptions. Based on the respective individual case decisions, the following article presents a procedure for proving interference in a total of 10 steps:

Definition of the construction schedule for undisturbed construction progress

Presentation of the framework conditions for undisturbed service provision

A conclusive factual presentation first requires the presentation of the contractual agreements with regard to the construction schedule to be drawn up. The decisive factors are in particular the start and completion of construction, but also individual interim deadlines and the other circumstances of the performance of the service.

Further framework conditions for the construction process to be planned result from the other contractual regulations, which must also be complied with by the Contractor. In various invitations to tender, for example, framework working times are often specified which may not be exceeded by the contractor without approval. However, a contractor may schedule shorter hours at any time within the scope of his freedom of disposition. The work performance remains owed, not the presence on the construction site.

Necessary factual presentation on the originally planned construction process

Based on the contractual framework, the contractor plans the details of the undisturbed service provision. This construction progress planning can be carried out either by adopting a construction progress plan provided by the client or (in the preferred variant) by drawing up your own construction progress plan.

This original construction schedule must show,
“that the construction time could have been met at all with the resources included in the price calculation if construction had proceeded undisturbed.”

This plan is not only the basis for assessing the effects of disruptions to the construction process, but also for checking the plausibility of the Contractor’s planned provision of services and the resources calculated for this purpose.

A comprehensible disturbance documentation therefore requires first of all an explanation of the execution planned by the contractor in the undisturbed construction process. In addition to the execution periods of the individual operations (start, duration, end), this includes above all daily working times, technological or capacity relationships between the schedule operations and ideally also information on the planned number of workers per operation.

If the plan is too coarse for the fault detection, a subsequent, further breakdown of the operations originally foreseen may be necessary. Analogous to the subsequent original calculation, there is nothing to prevent this breakdown if this subsequently created construction sequence actually also shows the undisturbed construction sequence planned by the contractor.

Explanation of the scope of weather conditions to be taken into account

Analogous to the BGH case law on costing, the client should not reject a construction schedule because it does not meet his expectations, provided there are no express contractual agreements on the content and structure of the construction schedule and the contractor has actually prepared and commenced his services in accordance with this construction schedule.

In this respect, it is not so important whether a construction schedule was expressly agreed or not. However, according to the dissenting and not uncontroversial opinion of the OLG Brandenburg of 02.12.2015, claims based on disruptions to the construction process may be excluded if the basis for the provision of services on the construction site has not been mutually agreed.

However, the schedule also does not require confirmation by the CLsince it is only the planning of the planned performance of services by the Contractor within the scope of his freedom of disposition that is important here.

It is more important that the Contractor actually organises his construction schedule according to these documents, that the construction schedule complies with the contractual specifications and that the Contractor is thus within his freedom of disposition freedom.

If, however, a construction schedule initially submitted by the Contractor has been amended by mutual agreement with the Client and thus made the contractual basis for the performance of the work, this mutually agreed contract schedule authoritatively. This does not apply to disruptions that occurred before the contract schedule was agreed, even if these disruptions were not included in the contract schedule.

Explanation of the scope of weather conditions to be taken into account

Most construction schedules do not explicitly indicate the weather conditions that must be taken into account for the undisturbed construction process. In the absence of a corresponding presentation of the facts, it is not possible to examine the extent to which these weather conditions, which had to be taken into account when the offer was made, have been taken into account.

In this respect, it must be explained which weather conditions would have had to be taken into account or have been taken into account in the undisturbed course of construction. These circumstances relate to the specific performance and the execution times in accordance with the original construction schedule.

Presentation and evaluation of the original cost estimate and the supplementary cost estimates

Mandatory necessity of handing over the original calculation

The original calculation is not only of considerable relevance as an update of the price determination basis, but also for claims for compensation (§ 642 BGB) or damages (§ 6 para. 6 VOB/B) for the determination of the amount of the claim due to disruptions in the construction process, since a plausible original calculation also shows the hypothetical financial situation of the claimant without the damaging delay in construction or the basis for the settlement cost calculation.

In order to be able to assert claims arising from a “disturbed” construction process at all, it is therefore imperative that the Handover of the original calculation required. In this regard, the Düsseldorf Higher Regional Court stated in its ruling of 21.11.2014:

„… Without a comprehensible presentation of the price bases on the basis of the contract/prime calculation to be submitted or a plausible (subsequent) calculation – an asserted claim for additional remuneration in the case of supplements within the meaning of § 2 No. 5 VOB/B or § 2 No. 6 VOB/B is inconclusive and the action must be dismissed as finally unfounded (and not as not due or currently unfounded as in the case of only a lack of verifiability). There is no room for recourse to the customary local price based on § 632 para. 2 BGB within the framework of §2 no. 5 or no. 6 VOB/B.”

According to the ruling of the Federal Court of Justice (BGH) of 18.12.2008, a subsequently prepared and submitted calculation subsequently prepared and submitted calculation is admissible if theif the contract prices emerge from it without contradiction.

Requirements for the original calculation

In principle, the client cannot reject a calculation just because it does not correspond to his ideas, unless there are express contractual agreements to this effect. For example, the AG cannot demand the breakdown of certain surcharges without corresponding specifications in the contract.

However, a corresponding breakdown of the original costing is absolutely necessary, particularly in the upcoming proof of the effects of disruptions to the construction process, in order to demonstrate the plausibility of the calculated estimates. The documents submitted for the original cost estimate should therefore contain the calculated costs for each item. hours as well as all cost estimates that make up the The bidder must show all the cost estimates that make up the unit prices quoted.

The essential basis of the calculation in this particular context are the Circumstances of the service provision. Therefore, the considerations, calculations and assumptions made in the course of pricing should also be explicitly documented in the course of the calculation.

Calculation of subcontractor services

The original cost estimate usually does not contain any further breakdown of the calculated costs for subcontractor services. This is unproblematic at least if no additional costs are claimed from these costing approaches.

However, as soon as additional costs are also to be claimed for subcontractors, the same requirements apply to the necessity of handing over the original cost estimate(s) of the subcontractors.

Alternatively, the contractor can also provide a breakdown of the subcontractor services so that the shares for the main main cost groups in the cost estimates for subcontractor services in the individual items can at least be estimated.

Submission of the supplementary calculations

In addition to the original cost estimate, the cost estimates for the individual supplements already raised should also be submitted and evaluated in order to show that any additional costs arising from the disrupted construction process have not already been covered by these supplements.

Proof of the plausibility of the original calculation and the original schedule

Necessary proof of plausibility

The basis of every fault documentation is the Plausibility check for the original construction schedule and the calculated costs of execution. On 28.01.2014, the Higher Regional Court of Cologne ruled that it is mandatory for a contractor to prove the plausibility of the original construction schedule in order to be able to assert claims against the client at all if the planned construction time is exceeded:

“The assumption of a causal connection between the conduct of the client and the exceeding of the planned construction period presupposes that the construction period could have been adhered to at all with the means included in the price calculation in the case of undisturbed construction progress. If this is not the case, any exceeding of the planned construction period is not due to a cause falling within the client’s sphere of responsibility”.

The best way to prove plausibility is to allocate the funds covered by “
of the price calculation
” to the individual operations of the routing.

Plausibility check based on the calculated working hours

Central for the plausibility proof are the calculated working hoursbut also the calculated expenses for equipment and subcontractor services. In the case of this assignment, construction progress planning and original costing show how the agreed construction work should be carried out in terms of costs and deadlines.

If an operation is to be carried out in-house, the target labour force of an operation resulting from the calculated labour hours and the originally planned duration of the operation shows whether the price and time calculation is plausible in the undisturbed construction process.

Plausibility of external services

If no or only very low wage hours have been assigned to individual operations, it should be investigated whether the work should be carried out by subcontractors for whom an original cost estimate naturally does not show any wage hours.

The adequacy of the calculated expenses must therefore be proven at least if additional costs are to be charged to subcontractors. Whether the calculated subcontractor costs are sufficient to be able to adhere to the planned operation durations in the undisturbed construction process can also be checked here by allocating the subcontractor costs and estimating the respective wage share.

Proof of adequate process durations on the basis of the actual undisturbed construction process

Alternatively, the adequacy of the calculated expenses in the undisturbed construction process can also be demonstrated on the basis of the (coinciding) actual process durations.

If, however, the individual operations in the actual undisturbed construction process could only be carried out with increased personnel expenditure compared to the original calculation, the plausibility proof for the operation durations is provided, but not for the calculated working hours.

Description of the actual construction process

The actual construction process is decisive for the proof of disruption.

Only in the rarest of cases are the services on the construction site carried out exactly as originally planned. Typical causes for the deviations of the actual construction progress up to the occurrence of the disruption can be both usual fluctuations in the performance of services, new dispositions by the Contractor and other delays in the performance of services for which the Client is not responsible. But also disruptions from the risk sphere of the client, for which the contractor has already received (or should have received) compensation at the time of the disruption, lead to scheduled or actual deviations from the originally planned, undisturbed construction process.

has therefore already in 2004 described all typical models of proof of disruption which are not based on the actual construction process and demanded:

“In order to demonstrate these conditions which give rise to a claim, it is necessary that the actual, and not the planned or calculated, course of construction up to the obstruction and the consequences of the obstruction be compared on the basis of a comparison of the hypothetical undisturbed actual course of construction with the disturbed actual course of construction. The planned construction schedule is an appropriate comparator only if it is the same as the actual construction schedule up to obstruction.”

Derivation of the actual construction sequence from the construction site documentation

As a rule, the actual execution times of the individual operations are determined on the basis of the daily construction reports kept during construction. These entries must be transferred to a construction progress plan and compared graphically with the undisturbed construction progress or the last planned construction progress that was undisturbed after the last disturbance. Therefore, the Contractor should enable a clear assignment of the entries in the daily construction reports to the processes of the construction schedule in his construction site documentation and explain them in the factual presentation of the actual construction process.

Ideally, the work performed each working day is not only described verbally when the daily construction reports are created, but the specific operation numbers from the original construction schedule are entered in the relevant daily construction reports.

Presentation of the planned schedule for the occurrence of the disruption, further undisturbed target construction process

The actual building situation at the time of the fault

The actual process for the overall measure is the basis for assessing the level of performance achieved when a specific disruption to the construction process occurs. This actual construction situation at the time of the disruption, in conjunction with the immediately planned further course of construction, forms the basis of comparison for assessing the impact of a specific disruption.

Only with access to the actual progress schedule can the Contractor demonstrate for each individual disruption how the construction progress was actually realised up to the time of the occurrence of a disruption and how the outstanding remaining work was to be performed at the time of the disruption.

The actual performance of services also includes supplementary services and self-inflicted disruptions to the construction process.



Decisiveness of the actual construction schedule

The actual effects on the construction process planned prior to the occurrence of the disruption shall be decisive for the assessment of the corresponding disruption of the construction process.

pointed out in 2004 that the originally planned construction schedule is only a suitable basis for comparison in exceptional cases:

The construction sequence originally planned, i.e. when the offer was submitted or the order was placed, is therefore generally irrelevant if deviations from the originally planned performance of services have already occurred between the start of construction and the start of the disruption.

Particularly if the contractor has drawn up internal construction schedules (which have changed compared to the calculation) during the performance of the service, these actual deployment schedules for the further performance of the service can be used as a basis for comparison for the assessment of the effects of construction disruptions.

If no consideration is given to the construction sequence actually planned at the start of the disruption, the effects of a specific disruption cannot be assessed and the factual argument becomes inconclusive.

Basis of comparison for the concrete target/actual comparison

target sequence
in the event of a disruption must therefore contain the actual performance of services for the past, but the further construction progress planned at this time for the future.

target plan
is the basis for the construction sequence-related representations of a concrete construction sequence disruption and is absolutely necessary for the conclusiveness of the factual presentation.

The target durations and relationships of the unperformed operations of the partial services in this target construction progress schedule are generally based on the latest planning for the construction progress. Without justification, the Contractor cannot claim any time surcharges compared to the original schedule.

Only if a shift to less favourable seasons or another causal dependency of disruption consequences on the calculated services (remaining services) has actually occurred, can a surcharge be granted on the originally planned remaining execution time.

This target schedule for the remaining work, which is based on the actual schedule up to the time of the disruption, is the basis for considering differences (e.g. delays) between the “disrupted” and the last actually planned construction schedule (not necessarily the same as the originally calculated construction schedule).

Willingness to perform and construction technology in line with the contract

Willingness to perform as a mandatory requirement for entitlement

One of the most important prerequisites for a claim under the most common basis for a claim, § 642 BGB, is the Contractor’s willingness to perform. Although performance can also be offered by keeping appropriate resources on site, the contractor should always also offer its services explicitly and formally in the written obstruction notice – regardless of the basis for the claim. Otherwise it may be difficult for the contractor to prove that he was always willing to perform within the framework of his secondary burden of proof.

It is also important that the contractor has not caused any delays of his own or that he delineates these delays in a clean and comprehensible manner.

No impediment in the case of non-contractual technology

According to the ruling of the Court of Appeal of 29.04.2008, a contractor can only claim obstructions if he performs his services on the basis of the concluded work contract and the technology provided for therein.

On 28 October 2015, the Higher Regional Court of Frankfurt confirmed that in the event that the Contractor offers a service which does not comply with the contract and which is not accepted by the Client, the conditions for default of acceptance pursuant to Section 642 of the German Civil Code do not exist. In the case decided upon, the client had refused to allow construction to begin on a pipe rehabilitation project planned by the contractor using a technology that was not in accordance with the contract and had not been approved. Although the contractor wanted to start the work and could not start because of the refusal of access to the construction site, no claims result from this execution which was not planned according to the contract.

No obstructions due to obvious planning mistakes

Even in the event that difficulties were already apparent at the time the offer was submitted, no obstructions may be asserted at the expense of the Client. However, a bidder need not anticipate that the requested specification will be inaccurate when making its calculation.

On the other hand, should the average bidder be confronted with the
“defectiveness of the performance specification […] virtually imposes itself”.
the consequences of the planning errors in the event of a breach of the duty to inform shall be interpreted in favour of the contracting authority.

Obstruction notification when the fault occurs

Requirement of written form

Both in cases of § 6 para. 6 VOB/B as well as § 642 BGB is an immediate, written, addressed to the client. Notice of delay pursuant to § 6 para. 1 VOB/B is mandatory.

The obstruction notice is also a prerequisite for a proper offer of performance by the debtor of the construction work in the event of delayed or dilatory cooperation by the client.

In addition, the client should also be informed of the temporal and monetary effects of disruptions to the construction process in the event of changes to the performance, and explicitly so even if the contractor (initially) assumes the existence of a claim to remuneration pursuant to § 2 VOB/B. Thus, in an older ruling of 21.12.1989, the Federal Court of Justice (BGH) decided that in general supplementary services (may) be obstructions which (may) require a notice of obstruction.

The wording of the obstruction notice should not be too demanding. Rather, for the notice of obstruction to be effective, it is important that it is clear from its content, taking into account the recipient’s horizon, that the contractor regards a certain circumstance as an obstruction and expects a remedy.

In an analogous interpretation of the judgment of the OLG Frankfurt of 16.03.2015, the term of § 6 para. 1 VOB/B is also complied with if a letter is signed, scanned and sent by e-mail.

Content of the obstruction notice

In order to emphasise the protective function of an obstruction notice, the Contractor should check the necessary obligations of the Client to cooperate in good time and remind the Client of the specific deadlines for outstanding decisions, documents or preliminary work even before a concrete obstruction occurs. This gives the AG the opportunity to exert a controlling influence on his vicarious agents. In this case, the actual obstruction notice not only meets with greater acceptance, but can also refer directly to the previously announced target date.

Since the vast majority of construction disruptions are based on Section 642 of the German Civil Code (BGB), the obstruction notice should always contain a concrete offer of performance and enable subsequent proof of the contractor’s ability and willingness to perform. Although the Contractor only has the secondary burden of proof, the Client is dependent on a corresponding presentation of the facts within the scope of the (counter-)evidence incumbent upon him.

Consequently, in order for a notice of obstruction to fulfil its function of informing, warning and protecting, it is essential that the obstructing circumstances are made available to the contracting authority in written form. The notice should state, in a manner that is comprehensible even to technical laypersons, which work was to be carried out and when, the circumstances due to which the planned work cannot be carried out, and that the contractor is ready and willing to perform.

Exception obviousness

Furthermore, the contractor should not rely on the fact that the impeding circumstances are obvious, as the requirements for the exception of obviousness are high.

Thus, a manifest disability pursuant to sec. Decision of the BGH of 25.06.2015

for example, if the client requests a rescheduling. This rescheduling is to be assigned to the risk sphere of the client and leads to a clear extension of the execution deadlines.

Such obviousness can also be assumed in the case of considerable additional quantities compared to the original invitation to tender, which clearly exceed the limit of § 2 No. 3 VOB/B.

Disability deregistration and documentation of disability effects

No compelling need for disability deregistration

According to VOB/B and current case law, the existence of an obstruction notice is not a mandatory prerequisite for proving a claim in the event of disruptions to the construction process. Nonetheless, disability sign-off is quite useful for evidential malfunction documentation.

The letter should describe and explain the specific effects of the obstruction on the most recently planned operations in the construction sequence and the effects on the following services.

For the later proof of the consequences of a concrete disruption of the construction process, it is also important to describe why the workers could not (or not completely) be deployed elsewhere or why the hindrance could not be prevented or at least limited by other measures within the scope of the duty to mitigate damages.

Facilitation of the verification through a disability deregistration

In the obstruction notice, the actual and concrete effects of the disruption on the construction process and, if possible, also the costs of the service provision should be presented once again. The disability notice should clarify and document, by reference to the disability notice, the disability impacts outlined therein (for the future).

A particular facilitation of the subsequent verification results if a construction progress plan with the concrete disturbance effects is also handed over with the deregistration, which shows the actual effects of a disturbance in comparison to the last planned construction progress plan.

In particular, an obstruction report should record when the indicated obstruction ended, how the obstruction indicated at the time of the occurrence of the obstruction actually affected the work, which work could or could not be carried out instead of the obstructed work, how the obstruction affects the further course of construction and which influencing factors lead to additional costs from the concrete obstruction.

Construction sequence-related presentation of actual scheduling effects of each individual disruption

Necessity of an independent assessment of each individual disorder

The contractor who asserts a claim for delay in construction must provide comprehensible, sufficiently detailed information for each individual disruption as to which work could not be carried out on the construction site due to which delay in planning documents and how this affected the construction site.

For this disturbance documentation, it is generally essential to have construction process-related representations of the effects of the individual construction process disturbances, comparing the actual and the target processes.

In order to show damage caused by a delay, it must be shown in concrete terms what difference results from a comparison between an undisturbed and a delayed construction process.

In its ruling of 24 February 2005, the Federal Court of Justice (BGH) requires that each individual disability be considered separately. The penultimate sentence of the BGH ruling of 24.02.2005 is unambiguous in this respect:

“It must be borne in mind that each individual disability is to be considered separately and is subject to independent assessment”

The new case law of the higher courts, most recently of the OLG Brandenburg with its ruling of 18.02.2016, also explicitly requires that a concrete construction process-related representation “of the respective disabilities” – that is, every single handicap – “comparing the actual and the target processes” – must also be in the plural and thus also for each individual disability – and explicitly also for claims for compensation under § 642 BGB

Scope of the necessary construction sequence-related representations

A construction process-related representation first requires the representation of the so-called reference state. This Reference state corresponds to the actual service provision up to the time of the fault.

After the point of failure, however, this reference plan shows the immediately planned future service provision based on the actual level of service achieved up to that point.

The status state, on the other hand, shows the effects of the concretely considered construction progress disturbance in comparison to the last reference plan. This plan also contains the actual construction sequence until the occurrence of the disturbance in question. In addition, however, the construction process that actually occurred up to the key date of the analysis due to the specific circumstances under consideration is now also presented. After the key date, this status plan in turn contains the future planned activity.

The effect of a concrete disruption in the construction process results from the difference between the last planned reference state and the status state that occurred due to the concrete disruption. This construction process-related representation shows, independent of the basis of the claim or the amount of the claim, how a circumstance has actually played out.

Whether these facts then also lead to claims on the part of the contractor is, of course, subject to a separate assessment.

Scope of the necessary construction sequence-related representations

The incident documentation should also state whether the obstruction effects could be reduced, for example, by rearranging construction sequences or using buffer times, or why this was not the case.

In particular, self-caused disruptions of the construction process and already commissioned supplementary services are to be taken into account in the presentation of the individual disruptive circumstances, as otherwise the determination of the claim would be “inconclusive”.

For supplementary services, a reservation with regard to further construction period-dependent effects and additional costs makes sense, since otherwise such additional costs could be excluded in an agreement on the supplementary price (a different opinion is held here, for example, by the OLG Munich, according to which supplementary services without reservation are not generally excluded from consideration).
The possibility of a change in the agreement in terms of timing and monetary effects is excluded, as this depends on the interpretation of the agreement in the individual case.

Methods to be rejected for the representation of construction process disturbances

In the application of the still widespread targetmethod, a mixed incorporation of the most diverse causes of disruptions over the entire construction period takes place in a single, disruption-modified construction schedule.

As a rule, these representations do not correspond to the actual construction process or the actual construction-related effects of an obstruction and are therefore not suitable for meeting the legal requirements for proving construction disruption.

Nor are the requirements of case law satisfied by merely listing construction defects. Nor is it sufficient merely to
“Delays, downtimes and holding costs to be presented. Rather, it must be specifically shown what the difference is in a comparison between an undisturbed construction schedule and the delayed construction schedule”

Concrete justification and determination of monetary claims for each individual disruption

Definition of the basis for the claim

Depending on the facts of a disruption of the construction process, the respective, disruption-specific basis for a claim and the procedure for the correct determination of the amount of the claim are determined. In the opinion of the OLG Hamm, a claim is only conclusive and amenable to an evidentiary hearing if the effects of the different bases of the claim (disturbances) are clearly set out separately from each other.

In a typical disrupted construction process, in addition to the Contractor’s own disruptions, claims for remuneration in accordance with § 2 Para. 5 VOB/B, claims for compensation pursuant to § 642 BGB and claims for damages pursuant to § 6 para. 6 VOB/B.

For each individual disruptive event, the basis for the claim must be specifically established and substantiated.

The financial effects of exceptional weather conditions on the otherwise undisturbed construction process must be borne by the construction contracting parties themselves in each case in the absence of “fault”.

Weather-related extensions of the construction period shall therefore not constitute a delay in acceptance on the part of the Client. The Client is also not responsible for providing the Contractor with adequate weather conditions for the execution of the construction work.

“The customer is therefore not in default of acceptance if the contractor is temporarily unable to perform due to unforeseen weather conditions”

Determining the amount of the claim for the individual construction disruptions

Reasons for Remuneration claims from § 1 para. 3 and § 1 para. 4 VOB/B result from the exercise of the client’s free, contractual rights to determine performance.

This requires a legal order on the part of the client to extend the construction period. Thus, even after the conclusion of the contract, the client may still unilaterally order changes to the construction design or services not agreed upon, for which the contractor’s business is set up. An express or implied order of the Principal within the meaning of § 2 No. 5 VOB/B always requires a legal declaration by the Principal.

In the event of a claim for remuneration on the basis of § 2 VOB/B, the additional costs shall be determined on the basis of the existing contract prices. The construction period may also be extended by the fact that unforeseen Additional quantities must be provided. The resulting additional costs, which are dependent on the construction period, are to be taken into account in any supplementary agreement in accordance with § 2 No. 3 VOB/B.

Unless there is at least one effective written reservation reservation further claims are excluded. On the other hand, the Contractor must include the expected quantity deviations as well as contingent and requirement items up to the materiality threshold of 10 % pursuant to § 2 No. 3 VOB/B in his construction schedule.

A claim for compensation according to § 642 BGB arises in the event of a delay in acceptance by the client.

This includes, in particular, the breach of the duty to cooperate – typically through the failure to provide inputs or decisions. In this respect, the client’s cooperation also includes the provision of a construction object ready for processing as “advance performance”. The amount of the claim is determined by the duration of the delay and the amount of the agreed remuneration, but in principle without risk or profit. In accordance with the case law of the OLG Dresden, compensation claims are to be understood as a comparison of the hypothetical situation without delay with the performance and the actual asset situation as a result of the delay to be calculated.

The amount of compensation is in turn significantly influenced by the original calculation – since only the plausible and declared adequate original calculation provides information about the hypothetical financial situation of the claimant without the damaging construction delay.

On the other hand claim for damages pursuant to § 6 para. 6 VOB/B in accordance with the difference procedure on the basis of the concrete, disruption-related change in the asset situation.

Necessity of accrual of already reimbursed additional costs

In any case, the additional costs resulting from the individual disruptions to the construction process must be distinguished from the calculated expenses in the original calculation or the individual supplementary services commissioned or claimed.



Prof. Dr.-Ing. Dipl.-Kfm. Thomas Heilfort, Dresden