Commercial Property & Construction Contracts: Practical Guidance | LegalDocuments.co.uk
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Construction projects and commercial property deals rarely fail because the building work goes wrong. More often, things unravel because the paperwork wasn't tight enough at the start. A payment schedule that nobody reads carefully, a scope of works that leaves too much to interpretation, a lease clause that quietly shifts a significant cost onto the wrong party, these are the sorts of oversights that turn into expensive disputes months or years down the line.
On this page I've pulled together practical guidance for anyone dealing with construction contracts or commercial property arrangements in England & Wales. Whether you're a contractor weighing up a lump sum versus a cost plus arrangement, a developer negotiating with an architect, or a landlord trying to make sense of a rent review, the goal here is to help you understand what matters before you sign. If you'd rather talk it through, there's an option to speak with an experienced legal adviser further down.
What this document is
Commercial property and construction contracts cover a broad spread of legal arrangements used whenever non-residential land, buildings, or building work change hands or get carried out. On the construction side, this includes the written agreements between employers, main contractors, subcontractors, consultants, and suppliers that set out who does what, when, for how much, and what happens if something goes wrong.
Common structures you'll come across include lump sum contracts, cost plus arrangements, time and materials agreements, unit pricing contracts, and design-build or management contracting frameworks. Each allocates risk between the parties in a different way, which is why choosing the right structure matters so much.
On the commercial property side, the documents tend to govern the relationship between landlords and tenants, or buyers and sellers. That includes leases, lease renewals, rent review memoranda, service charge arrangements, licences to assign or underlet, and property development agreements.
Across both areas, well-drafted documents set clear expectations on payment, timescales, variations, defects, insurance, and how disagreements get resolved, whether through negotiation, adjudication, arbitration, or the courts.
How to use this document
- Work out what you're actually agreeing to. Before you sign anything, read the whole document, not just the headline terms. Look at how the price is calculated, what triggers extra costs, who carries the risk for delays, and what the termination provisions say. If any clause is unclear, that's a signal to pause rather than push on.
- Match the contract type to the project. A lump sum contract suits projects with a well-defined scope; a cost plus or time and materials arrangement may work better where the scope is likely to evolve. Getting this wrong is one of the most common sources of disputes, so think carefully about which structure reflects the reality of your project.
- Check the payment mechanism and notice requirements. Construction contracts in England & Wales are often subject to the Housing Grants, Construction and Regeneration Act 1996, which imposes specific rules on payment notices, pay less notices, and the right to suspend for non-payment. Make sure the payment schedule is workable and that the notice deadlines are realistic for your team.
- Pin down variations, delays, and dispute resolution. Almost every project changes during delivery. The contract should set out how variations are priced and instructed, how extensions of time are claimed, and what happens when the parties disagree. Adjudication under the Construction Act is usually available, know whether your contract also requires mediation or arbitration first.
- Don't skip the commercial property detail. For leases and property transactions, the small print on repair obligations, service charges, rent review mechanisms, break clauses, and assignment rights can shift tens of thousands of pounds between the parties. Cross-check any heads of terms against the final document before signing, and raise anything inconsistent early.
Common questions
If you're dealing with this kind of situation, speak to an experienced legal adviser who can walk you through it — from £149.
Common questions
Q What's the difference between a lump sum and a cost plus construction contract?
With a lump sum contract, the contractor agrees to complete defined works for a fixed price, carrying most of the cost risk. A cost plus contract reimburses the contractor for actual costs incurred plus an agreed fee or percentage, shifting more risk to the employer but offering flexibility where the scope isn't fully known. The right choice depends on how well-defined the project is at the outset.
Q Does the Construction Act apply to my contract?
The Housing Grants, Construction and Regeneration Act 1996 (commonly called the Construction Act) applies to most construction contracts for work carried out in England, Wales, and Scotland, with some exceptions such as certain contracts with residential occupiers. Where it applies, it gives parties statutory rights around payment notices, interim payments, and adjudication. If you're unsure whether it covers your contract, it's worth checking before you rely on the provisions.
Q How do rent reviews in commercial leases usually work?
Commercial leases often include periodic rent reviews, typically every three or five years. The most common mechanism is an upwards-only open market review, meaning the rent can go up but not down. Other approaches include index-linked reviews tied to inflation, or fixed stepped increases. The wording of the review clause matters a great deal, so read it carefully and consider whether you need a memorandum recording the reviewed rent.
Q What's a service charge and who decides how much I pay?
In a commercial lease, the service charge covers the tenant's contribution towards the landlord's costs of maintaining common parts, the building structure, and shared services. The lease itself sets out what can be recovered, how it's apportioned between tenants, and what certification or consultation is required. Disputes often arise over whether particular costs are genuinely recoverable, so the drafting is worth scrutinising.
Q When should a contractor use a letter of intent?
Letters of intent are sometimes used to let work start before the full contract is finalised, for example, to order long-lead materials or begin mobilisation. They can be useful but they're also a common source of problems, because they often leave key terms unclear. If you're relying on one, set a clear cap on spend, a short expiry date, and get the full contract signed as quickly as possible.
Q What happens if a dispute arises during a construction project?
For contracts covered by the Construction Act, either party generally has the right to refer a dispute to adjudication at any time. Adjudication is a relatively fast process producing a decision that's binding unless overturned in later proceedings. Contracts may also require mediation, arbitration, or court proceedings for final resolution. The contract's dispute resolution clause will set out the sequence the parties are expected to follow.
Q Do I need planning permission referenced in my development agreement?
Property development agreements usually deal with planning in detail, because the value of the deal often depends on achieving a satisfactory planning permission. Typical provisions cover who is responsible for the application, what counts as an acceptable permission, what happens if permission is refused, and how appeal rights are handled. If planning is central to your transaction, the drafting here deserves close attention.
If you're dealing with this kind of situation, speak to an experienced legal adviser who can walk you through it — from £149.
Sources
This guide is based on primary UK law and official guidance.
- LegislationHousing Grants, Construction and Regeneration Act 1996legislation.gov.uk
- LegislationLandlord and Tenant Act 1954legislation.gov.uk
- Guidance · UK GovHM Land Registrygov.uk
- Official SourcePlanning Portalplanningportal.co.uk
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Legal disclaimer
This article is for general information only. It is a tool to help you find your way — not legal advice, and not a substitute for speaking to a qualified adviser about your situation.