In Spain, a country whose construction sector constitutes one of the main sources of GDP, it is not surprising that there is specific legislation governing construction contracts. These matters are primarily regulated by Law 38/1999 of 5 November (the “Spanish Building Act” – Ley de Ordenación de la Edificación; LOE), which establishes the guarantees and rights of end users and the obligations and liabilities of those involved in the construction process.

Before the LOE entered into force on 6 May 2000, the Civil Code (CC), in force since 1889, governed these contracts. The LOE is now the central statute, while the CC continues to regulate general contract law, contractual breach and construction outside the LOE.

Under Article 2.2, the LOE applies to permanent public or private projects comprising:

• new buildings, except minor, technically simple, single-floor works that are neither residential nor public;
• alterations changing an existing building’s architectural configuration or use; and
• alterations to buildings protected for environmental, historical or artistic reasons.

Regional civil laws in the Basque Country, Navarre, the Balearic Islands, Catalonia, Valencia, Aragon and Galicia may prevail over the CC in certain matters. The applicable law follows the inter-regional conflict rules in Articles 13–16 CC and should be checked before contracting.

In Catalonia, the differences from common civil law are particularly significant:

• Article 121-20 of its Civil Code sets a ten-year general limitation period for personal actions, compared with five years under Article 1964 of the CC; and
• Articles 621–24 et seq establish a separate regime for latent defects, and, although the LOE applies nationwide as basic state legislation, ancillary contractual obligations may be governed by Catalan law.

Other key rules are Law 9/2017 on Public Sector Contracts (LCSP), the Technical Building Code (CTE), which implements Article 3 of the LOE’s requirements on matters including fire safety and energy efficiency, and the consolidated Land and Urban Regeneration Act (Texto Refundido de la Ley de Suelo y Rehabilitación Urbana – TRLSRU), particularly for maintenance and land-planning matters.

In Spain, public works procurement has traditionally been organised through standard tender documents and contract templates. By contrast, the private sector has historically lacked a family of international standard contracts with a level of adoption comparable to the International Federation of Consulting Engineers (Fédération Internationale des Ingénieurs-Conseils – FIDIC) contracts, the New Engineering Contract (NEC) or Joint Contracts Tribunal (JCT) contracts. Nevertheless, the use of FIDIC contracts has increased in projects involving international financiers or contractors.

The most commonly used forms include the Red Book, intended for works where the design is primarily the employer’s responsibility, and the Silver Book, designed for engineering, procurement and construction (EPC) or turnkey projects and involving a substantial transfer of risk to the contractor, with particular emphasis on price and time certainty.

Their use in private property development nevertheless remains limited. The prevailing practice is to negotiate ad hoc contracts, often based on the developer’s own templates.

While Chapters I and II of the LOE address its scope and the technical requirements for building works, Chapter III identifies the building agents and their duties: the developer, designer, contractor, site manager, works manager, quality-control bodies and laboratories, product suppliers, and owners and users. Subcontractors are not listed, despite their practical importance.

The developer organises and promotes the project, appoints the designer and contractor and secures funding. It may be a public or private natural or legal person acting alone or collectively.

Under Article 9.2 of the LOE, the developer must hold title permitting construction on the site, provide the information and documents required for design and take out the Article 19 insurance, among other obligations. The developer funds the project and commissions its design and execution. Subcontractor appointment normally rests with the contractor, subject to agreed limits.

A self-developer building a home for personal use assumes the same duties and liabilities but is generally exempt from Article 19 insurance.

The contractor undertakes to execute all or part of the works. Financing normally remains with the developer, so the contractor rarely deals directly with lenders. Depending on the project, the contractor may be a large company or local firm and may engage specialist subcontractors.

Article 11 of the LOE requires the contractor to appoint a site director as its technical representative, provide the necessary personnel and materials, formalise permitted subcontracting and furnish statutory guarantees. Performance is governed by the contract, design, applicable law, lex artis (good technical and professional practice) and the project management team’s instructions.

Although omitted from the LOE’s list of building agents, subcontractors are regulated by Law 32/2006 of 18 October. They are usually specialist firms and, like the main contractor, assume an obligation of result: due care does not excuse defective work.

Contractors and subcontractors must verify that engaged companies are accredited and registered. Obtaining the relevant certificate satisfies this employment and occupational-risk duty. It is separate from the contractor’s civil liability under Article 17.6 of the LOE: the contractor remains directly liable for defects in subcontracted works, without prejudice to recourse against the subcontractor.

The developer may use equity, debt or both. Non-cash funding may include exchanging land for future units or a share of the completed development. External finance generally comes from banks, funds or alternative lenders.

The principal form of financing used in construction developments is the developer loan, which commonly finances planning fees, professional fees, taxes and construction. Lenders often require pre-sales, depending on the developer’s size and record. The developer loan benefits:

• the developer by providing funding and often a grace period;
• the lender through mortgage security over the land and completed units; and
• purchasers, who may assume the allocated debt on favourable terms.

In developer loans, mortgage liability is allocated among units. On sale, the developer may repay the unit’s share from the sale proceeds, or the purchaser may assume it by subrogation.

Only the developer has a contractual relationship with the lender, governed by the finance documents. The lender’s relationship with the other building agents is normally indirect, although drawdowns may depend on progress certificates issued by the project management team.

To protect purchasers making advance payments, the First Additional Provision of the LOE provides that, once the building permit has been obtained, advance payments for residential purchases must be secured together with statutory interest. Supreme Court case law has also imposed liability on banks receiving such payments into accounts not designated as special accounts.

The designer prepares the project under the developer’s contract and applicable technical and planning rules. Article 10 of the LOE requires an architect for residential and other principally non-industrial buildings. Engineering, technical engineering or architecture qualifications apply in other cases, supplemented by Law 12/1986.

An unsuitable qualification may invalidate the appointment and trigger professional discipline, so the developer should verify registration and competence. The designer must receive necessary information, co-ordinate sub-projects and obtain specialist input. It is common to appoint the designer as project manager during execution, who is responsible for compliance with the design, planning permission and other authorisations.

The works contract and annexed technical documents define the purpose and scope. A basic design (proyecto basico) is first submitted for planning permission, followed by the execution design (proyecto ejecutivo), which details the technical and construction solutions.

The project normally comprises the execution design, specifications identifying materials and finishes, a budget listing and valuing work items, and any supplementary drawings or programme, with the contract establishing their order of precedence to resolve inconsistencies.

The developer may request, and the contractor may propose, variations. Developer-requested changes may include agreed price and time adjustments. If agreement is impossible and the change can be separated, the original works may proceed without the affected item, which another contractor may later execute.

In lump-sum contracts, increased labour, material or resource costs are ordinarily the contractor’s risk. Additional payment requires a genuine addition, alteration or increase in the volume or value of the original scope, together with the developer’s written, oral or implied consent. No adjustment is due for work already within the contractor’s obligations. The parties determine the additional price. In the absence of agreement, courts often rely heavily on expert evidence.

Variations must also comply with planning permission and other authorisations, and where a new approval is required, it may delay completion. Contracts should therefore prescribe written approval, valuation and time-impact procedures. Unauthorised work risks non-payment and may also require reinstatement.

Tacit consent is frequently litigated. Supreme Court case law considers the developer’s direct knowledge, failure to object promptly and acceptance without material reservation. However, mere site presence, particularly without technical expertise, may be insufficient.

Design duties follow the LOE and the developer-designer contract. The designer is liable for design defects and for errors or omissions in calculations, studies, opinions or reports prepared by professionals it engages, subject to recourse. Jointly appointed designers are jointly and severally liable.

The designer and site manager are often the same person. A site manager accepting a third-party design is also liable for its omissions or defects, subject to recourse against the designer, and must therefore review it before taking charge. During construction, the site manager prepares the modifications requested or approved by the developer.

The contractor must follow the project plan and is not normally responsible for design unless the contract assigns it, as in design-and-build arrangements.

Execution responsibilities arise from the LOE, subcontracting law and the works contract. If the developer appoints several contractors for separate packages, the scope and co-ordination arrangements should be precisely defined.

The contractor is responsible for proper execution, its employees and subcontractors, and defects in products it purchases or accepts. Article of the 11.2.d LOE makes it liable for material damage caused by incompetence, inadequate professional or technical ability, negligence or breach by the site director or anyone under its responsibility. Unless prohibited, specialist work may be subcontracted.

Regarding project management team technical supervision:

• the site manager checks compliance with the project, authorisations and contract;
• the works manager monitors quality; and
• the health and safety co-ordinator monitors safety compliance.

The team usually certifies construction milestones.

The developer generally bears site-condition risk, subject to contractual allocation to the seller or transferor of building rights. Because it commissions the design, it must provide the designer with adequate information and conduct technical, legal, planning and environmental due diligence. Otherwise, permission may be refused, redesign required or works delayed or suspended.

Spanish land is often transferred as a specific identified property (cuerpo cierto), so a buyer taking it as-is normally assumes site risks unless the deed provides otherwise. The inherent risk should be distinguished from the parties’ allocation of its financial consequences.

Soil contamination is principally governed by Royal Decree 9/2005 and Law 7/2022. Under Article 34.1 of Law 7/2022, contaminated-land declarations fall within the competence of the autonomous communities. Liability rests first with the polluter and secondarily with current owners. If the polluter is unknown or insolvent, the buyer-developer may bear remediation costs even for pre-acquisition contamination. Contamination may also delay permits and threaten viability.

Existing buildings may contain asbestos, whose authorised specialist removal increases demolition time and cost. Underground obstructions and geotechnical conditions should be assessed before final design and, in all cases, before construction because they may require redesign or undermine viability.

Archaeological finds are governed by Law 16/1985 and regional law. Authorities may require preliminary investigations, and discoveries during construction must be reported, which may result in the works being suspended or made subject to conditions.

Building permits are regulated regionally and municipally rather than by one national regime, although the systems are broadly similar.

• New buildings and major refurbishment affecting structure, volume or external configuration require a prior major works licence (licencia de obras mayores).
• Minor repairs, refurbishment and fit-out generally require a prior notice (comunicación previa) or a responsible declaration (declaración responsable), permitting immediate commencement subject to later inspection. Inaccuracies or non-compliance may lead to suspension and reinstatement.

A permit, notice or declaration generally triggers provisional assessment or self-assessment of the municipal tax on construction, installations and works (impuesto sobre construcciones, instalaciones y obras – ICIO), commonly payable before commencement. Occupation after completion requires a first-occupation permit or equivalent filing. Environmental, heritage, archaeological, roads, water, coastal and other public-domain approvals may also be necessary.

The developer is legally responsible for permits, usually applied for by the architect or project manager on its behalf. The contractor commonly obtains permits specific to its methods or site operations, such as crane and waste-management permits.

Under Article 16 of the LOE, owners must preserve buildings through proper use and maintenance, while users must use them appropriately. Distinguishing construction defects from damage caused by inadequate maintenance is essential when determining liability and the validity of a claim.

These duties are linked to the developer’s obligation, upon the sale of a unit, to provide the end user with instructions for the use and maintenance of the building and its facilities.

Other legislation imposes similar obligations. Article 10 of the Horizontal Property Act (LPH) provides that works required for the proper maintenance and preservation of a property are mandatory and do not require prior approval from the Owners’ Association.

Likewise, Article 15.1 of the TRLSRU requires owners to maintain buildings and land in accordance with legal standards concerning safety, health, accessibility and appearance. The competent authority may order the necessary works and, in the event of non-compliance, carry them out at the owner’s expense.

Failure to comply with these maintenance obligations may limit or exclude the liability of another building agent where the damage was caused or exacerbated by the injured party.

2.2 The Contractor and 2.5 The Designer describe the contractor’s and designer’s principal duties, which the contract may supplement. Developers may also appoint firms to market units, manage or maintain the asset, assess market demand and optimise layouts or, on complex projects, co-ordinate costs, deadlines and participants as project manager.       

Quality and project compliance are checked during and after construction. The site manager verifies materials and structural execution and may order tests or inspections. Progress certificates issued by the project management team often support both payment and lender drawdowns.

For large, technically complex or environmentally demanding projects, quality-control bodies or laboratories may verify specific matters and issue reports or certificates, sometimes as funding conditions. After completion, all certificates and administrative approvals required for use or sale, including any first-occupancy licence, must be obtained.

On completion, the site manager and project manager sign the final works certificate (certificado final de obra), confirming conformity with the project and assuming responsibility for its accuracy.

Acceptance (recepción de la obra) is the contractor’s delivery of all works or a completed phase, with or without reservations. Under Article 6 of the LOE, this normally occurs within 30 days after the certified completion date. The developer and contractor must sign the acceptance certificate, which includes the final works certificate. If the developer does not attend or refuses without reasons, the contractor may record this.

The developer may reject incomplete or non-compliant works, identifying defects and a rectification period. Remediation is recorded in a separate certificate signed by the same parties. The date of acceptance is particularly important because it marks the beginning of the liability and warranty periods established under Article 17 of the LOE.

The LOE liability periods, running from unreserved acceptance or remediation of reservations, are:

• ten years for structural defects affecting stability or mechanical resistance;
• three years for habitability defects; and
• one year for completion or finishing defects, for which the contractor is specifically liable.

Contracts usually add a 12-month defects period during which the contractor rectifies notified defects at its cost. Longer periods and notification procedures may be agreed, but the LOE minimums cannot be reduced.

Before acceptance, the employer may reject incomplete or defective work or accept it with reservations. Afterwards, it may claim for reserved, latent and timely defects, seeking rectification, third-party repair at the liable party’s cost, price reduction, damages or, for material breach, termination.

The LOE sets no mandatory notice period, but proceedings must begin within two years after the damage occurs. An unequivocal extrajudicial demand, litigation or acknowledgement interrupts limitation. Damage arising after the relevant LOE period generally falls outside that regime. Contract claims coexist with LOE liability, require privity and are generally subject to a five-year period from breach.

The parties may freely agree a fixed or objectively determinable price. Fixed-price contracts are most common: the contractor generally bears labour and material inflation unless a review clause applies or the developer approves an increase in scope.

Article 1593 of the CC prevents a lump-sum contractor from increasing the price because wages or material costs rise if the works follow the agreed plans and conditions. Recognised exceptions include developer-authorised scope changes, unforeseeable supervening circumstances justifying application of the rebus sic stantibus doctrine or the principle of equivalence of performance, and post-contract regulatory or technical changes. Detailed scope, written variation procedures and exclusion of tacit consent best protect against extra-cost claims.

Unit-price contracts apply agreed rates to quantities actually executed. Cost-reimbursement contracts reimburse costs plus a fixed amount or percentage for overhead and profit. Prices normally include direct and indirect costs, profit and taxes, with periodic, certified or milestone payments.

Public contracts may use lump sums or unit prices. Exceptionally, the LCSP permits a provisional price where technical complexity or innovation requires commencement before the final amount is known.

Private-contract indexation applies only if agreed. Lump-sum contractors generally bear inflation, while unit-price and cost-reimbursement structures transfer more risk to the developer. Long-term or volatile projects often use official-index clauses with waiting periods, thresholds, caps, exclusions or cost-sharing formulas.

Force majeure or extraordinary, unforeseeable change may qualify the allocation. The exceptional rebus sic stantibus doctrine, notably recognised in Supreme Court Judgments 820/2012 of 17 January and 591/2014 of 15 October, applies only where the contractual balance is fundamentally altered. Material-price inflation in 2021–23 generated substantial Spanish litigation and arbitration. Hardship and index clauses reduced disputes.

Public price revision must satisfy Articles 103–105 of the LCSP and be stated in the tender documents. Law 2/2015 generally prohibits automatic public-sector indexation, subject to exceptions needed to preserve contractual economic balance.

Contracts typically govern payment dates, measurement and certification, objections and non-payment. Developers commonly retain 5–10% from certified sums as performance security until acceptance or the warranty period ends. Because retention affects cash flow, contractors may offer a bank guarantee, although developers often prefer retention for its simpler administration.

Advances for mobilisation, site establishment or materials are normally guaranteed and amortised through later payments. Interim payments are usually monthly and based on work certified by the project management team but may follow milestones.

The payment period is generally 30 calendar days and may not exceed 60 days. Late payment gives rise to contractual interest or, failing agreement, statutory interest. Law 3/2004 of 29 December, which implements Directive 2011/7/EU, establishes the 60-day maximum and statutory late-payment interest. It applies directly to business-to-business contracts even where the parties have not expressly incorporated its provisions.

Under Article 198 of the LCSP, public authorities must pay within 30 days after approval of the relevant certificates. If delay exceeds four months, the contractor may suspend performance; after six months, it may terminate the contract and claim compensation.

Invoices follow the payment structure: periodic certified invoices are usual, supplemented where agreed by advance, milestone and final settlement invoices. The final account adjusts outstanding sums, variations, deductions and retention releases and is supported by contractual measurements and certificates.

For VAT purposes, construction of residential property is generally subject to the reduced rate of 10% under Article 91.1.7 of the VAT Act, while commercial, industrial and other buildings are subject to the standard 21% rate. This distinction is relevant to the investor’s financial model, which should provide for input VAT and determine whether it is recoverable. The investor should also verify whether the reverse-charge mechanism under Article 84 applies to any part of the transaction.

The contractual programme sets the commencement date, activity sequence and duration, milestones and completion, and may identify dependencies, critical activities and dates for information, access and approvals.

A distinctive feature of Spanish practice is the distinction between the basic design and the detailed design. The basic design defines the general characteristics of the project and supports the planning-permission application but does not itself authorise construction. The detailed design develops it sufficiently for execution. This two-stage process is specific to Spanish practice and may surprise foreign investors accustomed to obtaining permission on the basis of a single design that also permits construction to begin. The programme should therefore allow for completion and approval of the detailed design, which may require several additional months in complex projects.

The developer provides the site, licences and necessary information, takes the decisions reserved to it and approves relevant changes. The designer prepares the basic design and the detailed construction design. The contractor develops and periodically updates the construction programme; co-ordinates labour, materials, equipment and subcontractors; and executes the works in accordance with the design. The project management team monitors technical progress, quality and the quantities actually completed.

The programme is protected through periodic reporting duties, procedures requiring the contractor to update it and contractual rules governing milestones, extensions of time, delays and variations. Progress certificates and milestone payments may provide additional control.

Royal Decree 1627/1997 of 24 October requires a health and safety co-ordinator during the design phase where more than one designer is involved, and during construction where more than one company or a self-employed contractor with workers participates. Failure to appoint the co-ordinator on a site involving several contractors may create administrative or criminal liability and delay commencement, because opening the site requires a health and safety plan approved by the co-ordinator. The developer is responsible for the appointment and should account for both the cost and this prerequisite from the outset of the project programme.

In public works, execution normally begins with a site-layout verification report within one month of contract formalisation, confirming whether commencement is possible and recording any reservations.

The contractor must:

• notify any delay within the contractual period;
• identify its cause and effects on the programme; and
• formally request an extension.

The developer and project management team assess the event and may require mitigation measures or a recovery programme.

Where delay is attributable to the contractor, contractual penalties are generally imposed or damages may be claimed. Where it results from the developer, approved variations, delayed instructions or causes outside the contractor’s responsibility, the contractor may be entitled to an extension and, where the contract permits and the costs are properly evidenced, compensation for additional time-related expenses.

Delay penalties are governed by Articles 1152 to 1155 of the CC. Article 1154 permits courts to reduce a penalty where the principal obligation has been partially performed. A substantial contractual penalty may therefore be moderated where the contractor has made significant progress, reducing its deterrent effect. In Spanish private contracts, delay penalties commonly range from 0.05% to 0.15% of the contract price for each day of delay, usually subject to an overall cap of 5% to 10%. Penalties exceeding these ranges may face a greater risk of judicial moderation, particularly where most of the works have already been completed. FIDIC forms generally provide predetermined liquidated damages and clearer relief events, which may reduce disputes.

For concurrent delay, an extension and financial compensation may be granted where delay attributable to the developer effectively and independently affected the contractual completion date. Spanish courts have not developed a uniform or systematic approach comparable to Clause 8.5 of the 2017 FIDIC Red Book or the English Malmaison approach. In practice, contractors are substantially better placed in a dispute where they maintain an updated programme, preserve contemporaneous records and issue real-time notices identifying each delay event and its critical-path impact. Developers should require regular programme updates and immediate notification of delay events, so contractor delays are documented before becoming intertwined with delays attributable to the developer or third parties.

The timeframe for the performance of a works contract can be a matter of great importance to the developer, whether they are a professional or a private individual.

From the perspective of a professional developer, the project’s profitability is closely linked to the start date of construction or the marketing of the residential units. This is particularly important when the financing of the works has been structured on the assumption that, by a certain date, the project will begin to generate sufficient income to service the loan granted or recoup the capital invested.

From the perspective of the private developer, a delay may disrupt the planned schedule for moving into their home and, in turn, lead to an increase in the costs initially anticipated, such as rent, storage of furniture or other associated expenses. However, the economic and practical significance of the timeframe does not mean that any delay, in itself, can justify the termination of the contract.

Generally speaking, a delay or non-significant late performance will rarely be sufficient to justify termination of the contract on the grounds of breach by the builder. For Article 1124 of the CC to apply, it is not sufficient merely for there to be a fundamental, serious and unjustified breach. It is also necessary to take into account other requirements, such as the reciprocity of the obligations, their enforceability and the claimant’s fulfilment of their own obligations.

For this reason, and as set out in the previous section, it is common for works contracts to incorporate mechanisms designed to reduce litigation and limit the scope of judicial discretion. It is also common to agree that, once a certain time limit has been exceeded, the developer is entitled to seek termination of the contract.

In both cases, the wording of these so-called penalty clauses must be precise and technically sound, and it must be clearly stated whether such a clause is a penalty that is in lieu of, or in addition to, any damages that may arise from the breach – see Article 1152 of the CC and Supreme Court Judgment of 26 June 2026 (ROJ: Supreme Court Judgment 3112/2026).

For public contracts, contractor-attributable delay lends the authority to terminate or impose daily penalties – normally EUR0.60 per EUR1,000 of the VAT-exclusive price unless the tender documents justify another rate. Unlike private penalties, which must be agreed, the public regime and its revision are statutory.

In private contracts, the contractor requests an extension by written notice identifying the cause, estimated duration and programme effect, updating the request when the final impact is known and supplying evidence. Grounds typically include variations, delayed site access, late developer information or instructions and administrative delays not attributable to the contractor. Cost recovery depend on the contract.

Public requests follow Articles 195 et seq of the LCSP and mandatory application and decision periods. Failure to respond within the prescribed period is treated as a refusal, which the contractor must challenge to preserve the claim. Unlike in private contracts, an extension may require a formal contract amendment published on the contracting authority’s profile.

Article 1105 of the CC covers events that were unforeseeable or, if foreseeable, unavoidable and excludes liability unless the law or obligation provides otherwise. It encompasses fortuitous events and force majeure: the former are usually characterised by unforeseeability and the latter by inevitability. Force majeure requires an external event beyond the parties’ control causing material impossibility without debtor fault.

Typical examples are catastrophic natural events and acts of public authority, but courts apply the doctrine restrictively. Supreme Court Judgment 1070/2024 of 24 July held that COVID-19-related income loss did not extinguish rent: monetary debts are generic obligations (genus nunquam perit; Article 1182 of the CC a contrario), and insolvency is not objective impossibility. Pandemic imbalance was instead considered under rebus sic stantibus (see Supreme Court Judgment 1891/2025 of 18 December).

Construction contracts usually define qualifying events and allocate their time and cost effects under Article 1255 of the CC. Risk may rest with the contractor, be excluded from its responsibility or be shared: suspension costs otherwise generally fall on the developer.

Article 239 of the LCSP specifically governs force majeure in public contracts through a restrictive, non-exhaustive list, including lightning fires and wartime violence. A non-negligent contractor is entitled to compensation for resulting loss or damage during performance.

Fortuitous events also fall under Article 1105 of the CC but concern unforeseeable occurrences, such as unexpected archaeological remains. Parties may define them and allocate their price and time consequences contractually.

The LCSP has no separate fortuitous-event regime, but an authority must extend time, at least by the period lost unless less is requested, where non-contractor causes delay and the contractor remains willing to perform.

Force majeure and fortuitous events prevent performance and may exclude breach liability. Rebus sic stantibus instead addresses an extraordinary and unforeseeable post-contract change that, without making performance impossible, substantially disrupts the contractual balance. The latter, as an exceptional case-law doctrine, requires a supervening event beyond the parties’ control, whose risk was not allocated and which makes performance on the original terms unreasonable.

Spanish law does not recognise “disruption” as a specific legal concept or as a separate category. It is a notion imported from Anglo-Saxon soft law – notably the SCL Delay and Disruption Protocol (second ed, 2017) – the use of which in Spain is, in practice, limited to international contracts (FIDIC and EPC contracts) and arbitration. In particular, the distinction between “delay” and “disruption”, which is central in common law, is not codified in Spanish law. This does not mean, however, that the economic problem described by “disruption” lacks a solution: the legal system resolves it through functionally equivalent, albeit dogmatically distinct, means.

It is worth clarifying the concept so as not to confuse it with “delay”. Whilst “delay” affects the critical path and the completion date – and entitles the party, where applicable, to an extension of time” – “disruption” undermines the contractor’s productivity, resulting in a loss of output and consequent cost overrun, often without delaying completion. Hence, an essential practical consequence is that disruption does not justify an extension of time, but rather a claim for compensation – and obtaining an extension of time does not, in itself, remedy the additional costs arising from the loss of output. These are distinct claims, with separate grounds and evidence.

At the contractual level, nothing prevents the parties, by virtue of the principle of freedom of contract (Article 1255 of the CC), from defining the circumstances constituting disruption and attaching to them consequences relating both to financial matters and to the performance period. This is standard practice in the aforementioned international standard forms.

In the absence of an express provision, the natural course of action in private contracts is contractual liability for breach, defective performance or default on the part of the client (Articles 1101 and 1124 of the CC), for which compensation covers actual loss and loss of profit (Article 1106 of the CC) and is integrated with the requirements of good faith and the duties of co-operation (Article 1258 of the CC).

In a works contract, Article 1593 of the CC – relating to increased costs arising from changes to the plans, a rudimentary equivalent of “variations” – and Article 1594 of the CC, concerning the client’s withdrawal from the contract, are also relevant. None of these provisions treat “loss of productivity” as a separate category: the additional cost caused by a change in the pace of execution is classified as actual damage, subject to the general rules on causation and the burden of proof (Article 217 of the Civil Procedure Act).

In public procurement, the Public Procurement Act (LCSP) provides the most developed analogous provisions, aimed at restoring the balance of performance. These include:

• modification of the contract or ius variandi (Articles 203 to 207 of the LCSP), which governs modifications entitling the contractor to compensation;
• suspension attributable to the Administration (Article 208 of the LCSP), which obliges the Administration to pay damages that have been effectively proven – including the maintenance of guarantees, personnel necessarily assigned to the works and immobilised machinery – precisely the type of additional cost sought in a disruption claim; and
• the principle of risk and venture (Article 197 of the LCSP), which acts as a limit in that only that which is attributable to the Administration is compensable.

In the context of concessions, the maintenance of the economic balance of the contract (Articles 270 and 290 of the LCSP) fulfils a similar function.

As regards proving the case, disruption is, first and foremost, a factual matter of causation and quantification. It is not sufficient to allege in general terms that the progress of the works was disrupted: it is necessary to identify each operation affected and establish the link between the event and the loss of productivity, with contemporary records – daily reports, the base programme and measurements of labour and machinery by activity – constituting the decisive evidence.

Although the concept is not specifically named, there is nothing to prevent the use in court of the “measured mile” method – which compares productivity in an undisturbed period or area with that in the affected period or area, attributing the difference to the disruption – as a simple means of proving the extent of actual loss. Its admissibility does not depend on whether the category has its own specific name in our law, but rather on the robustness of the records provided, in accordance with the allocation of the burden of proof laid down in Article 217 of the Civil Procedure Act (Ley de Enjuiciamiento Civil – LEC).

Article 1102 of the CC makes any advance waiver or exclusion of liability for wilful misconduct void. The injured party may claim despite such wording. Negligence liability under Articles 1101 and 1104 of the CC may be judicially moderated according to the circumstances.

Accordingly, negligence may be limited, but restrictions, particularly gross negligence, must be drafted carefully to avoid conflict with law, public policy or good faith.

The CC regulates wilful misconduct and negligence but does not codify degrees of negligence. Wilful misconduct is conscious and voluntary breach. Gross negligence, sometimes treated similarly to wilful or eventual misconduct, is a serious failure to exercise the diligence required by the obligation and circumstances under Article 1104 of the CC.

Parties may cap or exclude contractual liability subject to mandatory law, good faith and public policy. Caps often reference the contract price or professional fees. Delay may have a sub-cap, indirect losses may be excluded and penalties may substitute for damages. Spanish contractors often accept an overall cap of 100% of the contract price and a delay cap of 5–10%, with exclusions for lost profit, rent or reputation.

Article 17.8 of the LOE prevents waiver or reduction of statutory liability and warranty periods and protects owners and later purchasers. Thus, a developer-contractor cap cannot defeat a purchaser’s full structural-defect claim against the developer. Recourse against the contractor remains limited by their contract. Residential caps should therefore carve out third-party purchaser claims.

Personal injury, confidentiality, environmental damage and third-party claims are also commonly excluded from caps. Internal risk allocation remains possible, but consumer clauses unfairly restricting statutory rights are void.

Larger contracts use indemnities to allocate specific risks, generally more narrowly than common-law forms. Mandatory rules apply, and wilful misconduct cannot be excluded.

Contractors commonly indemnify employers for works-related personal injury and property damage, regulatory and safety breaches, subcontractor defaults, employment and social-security claims, environmental or waste liabilities and third-party IP infringement. Employers may indemnify contractors for employer-supplied information, designs or instructions, pre-existing contamination and employer-responsible third-party claims.

The clause should define triggers, recoverable loss, first- and third-party claims, defence costs and whether fault or breach is required. Otherwise, CC rules require breach, loss and causation, with damages covering actual loss and lost profit. Indemnities do not displace statutory liability to authorities, employees, users or other third parties, including mandatory LOE liability.

Under the LOE, for the construction or major rehabilitation of buildings whose principal use is residential, it is mandatory to provide a ten-year structural damage guarantee (seguro decenal). The guarantee may take the form of material damage insurance, surety insurance or a financial guarantee. It covers, for ten years, material damage caused by defects affecting structural elements and directly compromising the building’s mechanical resistance or stability. The minimum guaranteed amount is 100% of the final material execution cost of the works, including professional fees.

The developer normally takes out the guarantee for the benefit of itself and successive purchasers of the building or its units. However, the developer and contractor may expressly agree that the contractor will take out the guarantee on the developer’s behalf.

Apart from the mandatory ten-year structural guarantee, larger construction contracts frequently require additional contractual security. Their amount, duration, scope and enforcement depend on the terms agreed by the parties.

The guarantees most commonly provided by contractors are as follows.

• Performance guarantees securing the proper and timely performance of the contractor’s obligations. Depending on their wording, they may cover failure to complete the works, defective or non-compliant performance, delay-related liabilities and liquidated damages, and losses arising from termination.
• Advance payment guarantees securing repayment of any advance paid by the employer to the extent that it has not yet been amortised through interim payments. These guarantees are commonly reduced progressively as the advance is recovered.
• Retention guarantees allowing the contractor to replace the cash retention deducted from interim payments with a bank or insurance guarantee. They usually secure the contractor’s outstanding obligations until takeover or expiry of the defects liability period.
• Defects or warranty guarantees remaining in force after takeover and securing the contractor’s obligation to rectify defects notified during the contractual defects liability period.
• Parent company guarantees, typically required where the contractor is a subsidiary or special purpose vehicle. Their scope may include payment and performance obligations, completion of the works and liabilities arising following termination.

Guarantees may be provided through a bank guarantee, surety insurance, a cash deposit, retention from interim payments or a parent company guarantee. Bank guarantees and surety instruments are frequently drafted as first-demand guarantees. The instrument should clearly state the secured amount, expiry date, reduction and release mechanisms, documents required for a demand, any obligation to replenish the security following a call and whether the employer must prove the underlying breach.

Construction insurance combines mandatory cover with policies allocated by contract, which should identify the policyholder, insureds, limits, deductibles and duration.

Construction all-risks insurance, usually placed by the developer but sometimes the contractor, covers accidental physical loss or damage to works, materials and temporary works, including fire, flooding, theft, collapse and damage to existing or adjoining property.

The developer must generally obtain the seguro decenal described in 7.2 Guarantees. The LOE also contemplates one-year finishing and three-year habitability cover, but these are generally not compulsory. Contractors usually maintain civil liability insurance for personal injury, third-party property damage, subcontractors and, where covered, workplace accidents, plus plant and equipment cover. Designers usually carry professional indemnity insurance.

Except for mandatory decennial insurance, the parties determine cover. Insurance neither caps nor replaces contractual or statutory liability.

Construction contracts usually address the possible insolvency of either party by providing rights to request additional security, suspend performance, call guarantees or terminate. These provisions remain subject to the mandatory rules of the Spanish Insolvency Law (Texto Refundido de la Ley Concursal). Under Spanish Insolvency Law, the declaration of insolvency or opening of the liquidation phase cannot automatically terminate the construction contract, and clauses allowing its suspension, modification or termination solely on those grounds can be deemed ineffective.

The consequences differ depending on whether the contractor or the employer becomes insolvent. In the event of contractor insolvency, contracts commonly give the employer rights to secure the site, take possession of project documentation and materials for which it has paid, call performance or advance payment guarantees, appoint a replacement contractor and step into or require the assignment of subcontracts. These rights must generally be linked to an actual contractual breach, abandonment or failure to perform, rather than to the insolvency declaration itself.

In the event of employer insolvency, the contractor will commonly seek the right to require payment security and to suspend or terminate the works in case of failure to make payments when due.

Termination may still be sought for breaches occurring after the insolvency declaration, although the application must be made to the insolvency court (Juzgado de lo Mercantil). The debtor or insolvency administrator may oppose termination and request that the contract remain in force where this is in the interests of the insolvency proceedings. The debtor or insolvency administrator may also seek judicial termination of a reciprocal contract where this is in the interests of the insolvency proceedings, even in the absence of a contractual termination event.

In larger Spanish construction projects, the parties often agree mechanisms for sharing risks that neither side can fully control, although most risks are allocated primarily to one party. Shared-risk mechanisms are most often used for:

• unforeseen ground conditions;
• pre-existing contamination;
• archaeological discoveries;
• exceptional material price increases or shortages;
• changes in law, authority or utility delays; and
• force majeure events.

They may also apply to design development, interfaces with other contractors and changes required by the permitting authorities, although this is less usual.

These risks are usually addressed through agreed assumptions, thresholds, caps and relief mechanisms. For example:

• the contractor may bear cost increases up to an agreed percentage, with increases above that threshold being shared or entitling it to a price adjustment;
• unforeseen site conditions may be treated as variations where they could not reasonably have been identified from the information provided by the employer; and
• force majeure and authority-related delays commonly entitle the contractor to an extension of time, although additional costs may be borne by each party, shared between them or allocated according to the cause and duration of the event.

Shared risks are generally priced through contingency allowances, provisional sums, agreed unit rates, indexation or price-adjustment formulas, or reimbursement of actual costs plus an agreed mark-up. Target-cost and open-book contracts may also provide for savings and overruns to be shared in agreed proportions. On the other hand, under fixed-price contracts, the contractor usually includes a risk premium in the contract price for risks allocated to it, while expressly excluded or shared risks are addressed through the variation and extension-of-time procedures.

The contractor must provide a suitably qualified team and remain responsible for recruitment, supervision, remuneration and compliance with employment and social security obligations.

The contract will normally require compliance with employment, subcontracting, immigration and health and safety legislation, both by the contractor and throughout its subcontracting chain. Employers often request evidence that wages and social security contributions are up to date and reserve rights to restrict site access, withhold payments or require corrective measures if breaches are identified.

Labour clauses are also becoming more common, particularly in larger developments. These clauses typically require compliance with the applicable collective bargaining agreement and minimum standards regarding wages, working time, equality and working conditions, with the aim of limiting unlawful employment-related liabilities.

Subcontracting is standard for specialist trades. Contracts generally permit it subject to notice or employer approval for key firms or packages, and reasonable rejection on technical, financial or compliance grounds. Approval does not release the main contractor, which remains responsible for quality, time and execution and must flow down technical, insurance, confidentiality and safety obligations.

Under Article 5 on Law 32/2006 on Subcontracting in Construction (LSSC), the chain is usually limited to three tiers below the main contractor. Self-employed workers and labour-only subcontractors may not subcontract further. An extra tier is allowed only for specified specialist, technical, unforeseen or force-majeure reasons, with prior project-management approval and a book entry.

Larger contracts may add audit rights, restrictions on replacing approved subcontractors and employer step-in or assignment of key subcontracts after main-contract termination.

Spanish Intellectual Property Law (Real Decreto Legislativo 1/1996, de 12 de abril, por el que se aprueba el texto refundido de la Ley de Propiedad Intelectual) protects original architectural and engineering projects, plans, models and designs. Unless the relevant exploitation rights have been assigned or licensed, they remain with the author.

Regarding IP, construction contracts in Spain usually distinguish between documents supplied by the employer and those prepared by the contractor. The contractor is normally permitted to use the employer’s designs and technical information only for the purposes of the works and must keep them confidential. Where the contractor produces design documents for the project, the contract will generally require it either to grant the employer a licence to use, reproduce and modify those documents or to assign the relevant exploitation rights in them (licencia de uso). This may cover drawings, calculations, building information modelling (BIM) models and as-built documentation.

The rights granted to the employer normally extend to the construction, completion, operation, maintenance, repair and alteration of the building and continue after termination, allowing the works to be completed by a replacement contractor. Pre-existing methods, software, standard details and know-how generally remain with the contractor, although the employer is usually granted the rights needed to use the project documentation. The clause should specify the duration and territorial scope of the rights granted, the permitted uses and whether the documents may be modified or made available to other contractors, consultants, purchasers or operators involved in the project.

The contractor is commonly required to obtain equivalent rights from its designers, subcontractors and suppliers. The contract may include protection against third-party IP claims and require the delivery of editable and final project files at completion or following early termination. Any licence or assignment remains subject to the author’s moral rights, which are inalienable and cannot be waived under Spanish IP law.

Under the CC, the non-defaulting party may demand performance or terminate, with interest and damages, including causally linked lost profit.

For defective or incomplete works, the employer may require rectification or completion, use a third party at the contractor’s cost and recover loss. In case of delay, it may claim agreed damages or a substitutive penalty and, if sufficiently serious, terminate. Payment withholding, guarantee calls and termination for abandonment, persistent delay or unremedied defects are also common.

The contractor may claim unpaid sums, interest and recovery costs, and time or money for employer-caused access delay, late instructions, changes or non-payment. Serious breach may justify suspension or termination. Commercial debts accrue late-payment interest after expiry of the payment period.

Contractual remedies coexist with the statutory liabilities of contractors, designers and other building agents under the LOE – as described in 3.11 Defects and Defects Liability Period. Under Article 1597 of the CC, subcontractors may claim directly from the employer up to the amount owed to the main contractor when the claim is made.

Contracts often cap the contractor’s liability by reference to price, with separate limits for delay or particular risks, and exclude specified lost profit, use, financing cost or other losses. Because Spanish law does not precisely define indirect or consequential loss, excluded heads should be listed.

The parties may make liquidated damages the sole financial remedy for delay or require an opportunity to rectify defects before third-party intervention. A contractual penalty may replace damages and interest. Performance and penalty are cumulative only if expressly agreed, and courts may reduce the penalty after partial or irregular performance.

Limits cannot waive wilful misconduct, breach mandatory law or prejudice owners and later purchasers under the LOE. Consumer clauses restricting performance, damages or termination rights may be unfair and unenforceable.

Sole-remedy clauses in larger projects usually address a defined breach, such as making liquidated damages the employer’s only monetary remedy for delay or requiring contractor rectification before third-party repair. They are generally enforceable if clear and fair and should identify the breach, available remedy and exclusions. Ambiguity will not normally waive unmentioned remedies. They cannot exclude wilful misconduct, mandatory statutory liability or third-party LOE rights.

Contractors commonly seek to exclude lost profit, revenue or rent, loss of use, financing cost and reputational damage. In developments, lost rent and extra finance costs are heavily negotiated because delay may make them foreseeable. Specific heads should be listed rather than relying only on indirect or consequential loss terminology.

Exclusions normally do not cover completion or rectification cost, physical project damage, agreed delay damages or third-party claims. Larger contracts also carve out personal injury, confidentiality and IP breaches, indemnified amounts and mandatory LOE liability to owners and purchasers.

Contracts regulate rather than exclude retention and suspension. Employers may retain an agreed percentage and withhold or set off sums for incomplete or defective work. Without an express set-off clause, debts must be due, liquid and enforceable.

Contractor suspension is usually limited to serious or prolonged non-payment after notice and a cure period, and work may have to continue during valuation disputes. Suspension without clear contractual support is risky, although sufficiently serious breach may justify it. These rights may be contractually restricted, subject to mandatory law.

Employers commonly terminate for abandonment, material or persistent delay, failure to remedy serious defects, unauthorised suspension or other substantial breach. Article 1124 of the CC also permits either party to terminate for sufficiently serious breach of a reciprocal obligation. After contractor default, the employer may secure the site and documents, appoint a replacement and recover proven completion costs. The contractor remains entitled to payment for compliant work, subject to deductions and set-off.

Under Article 1594 of the CC, the employer may discontinue without default but must pay for costs, executed work and the profit the contractor would have earned. Contracts often regulate valuation and handover.

Contractor termination rights are narrower and usually arise from prolonged non-payment, denied site access, extended employer suspension or another serious obstruction, generally after notice and cure. A justified termination supports outstanding payments, demobilisation cost and proven damages.

Civil jurisdiction is governed principally by Law 1/2000 on Civil Procedure (LEC), the Organic Law on the Judiciary and applicable treaties. Once Spanish jurisdiction is established, both subject-matter and territorial competence must be identified.

LOE defect and building-agent claims ordinarily belong to the civil courts. Article 45 of the LEC gives courts of first instance first-instance jurisdiction over civil matters not assigned elsewhere.

Under Articles 50 and 51 of the LEC, territorial jurisdiction generally lies at the natural-person defendant’s domicile or the legal-person defendant’s registered office, subject to Article 52 of the LEC (special forums). Exorbitant jurisdiction clauses in consumer contracts are void. With multiple defendants, Article 53 may allow suit at any defendant’s domicile, according to the claimant’s choice.

MASC

Since Organic Law 1/2025 of 2 January entered into force in April 2025, an attempt to use an appropriate dispute-resolution method (medios adecuados de solución de controversias – MASC) is generally a procedural prerequisite to a civil claim, and evidence of an unsuccessful attempt must accompany the pleading. An agreement becomes enforceable if recorded in a public deed or approved by a court.

Available methods include:

• mediation, where a mediator facilitates the parties’ agreement;
• conciliation, where the conciliator may propose solutions;
• a non-binding neutral expert opinion; and
• a confidential binding offer (binding on the offeror if expressly accepted).

The law regulates these methods’ requirements, effects and deadlines. MASC proceedings are confidential, so their documents generally cannot be used in later litigation, and commencement suspends limitation and expiry periods.

Mediation

Law 5/2012 governs civil and commercial mediation, excluding criminal, public-authority and labour mediation. Under Article 4, a mediation request interrupts limitation or suspends expiry when received by the mediator or filed with an institution.

Public or private, Spanish or foreign mediation institutions organise rather than personally conduct mediation, and must ensure a transparent mediator appointment process and disclose qualifications, specialisation and experience. Article 9 protects the procedure and documents as confidential, apart from with respect to whether mediation occurred and its subject.

Arbitration

Act 60/2003 on Arbitration (LA), based on the UNCITRAL Model Law and a monist system, governs disputes over freely disposable matters, including private construction relationships. Arbitration requires a clause or separate agreement clearly submitting existing or future disputes arising from a defined legal relationship.

Consumer and user protection legislation declares null and void any arbitration clause included in sales contracts where the seller is a trader and the buyer is a consumer.

The arbitral decision is formalised by means of an award, which is enforceable by compulsory execution, with the court of first instance of the place where the award was made having jurisdiction. A challenge to the award is brought by means of an action for annulment, not as a second instance or as a review of the merits of the dispute, but as a mechanism limited to reviewing the validity of the arbitration. The grounds for annulment are exhaustive and include, amongst others, the absence or invalidity of the arbitration agreement and a decision on matters not subject to arbitration.