A lease work letter is the exhibit attached to a commercial lease that governs the build-out of the space: it defines what the landlord delivers, what the tenant builds, who pays for each piece, how construction money flows, and what remedies apply when something slips. It binds both parties as firmly as the lease itself, and on construction questions it usually controls over the lease when the two documents disagree. For a tenant signing commercial space, this is where the real money decisions live.
What a Work Letter Is and Where It Sits
The work letter is a formal exhibit to the lease, often labeled Exhibit B or Exhibit C depending on how the landlord’s attorney organized the package. Courts enforce it the same way they enforce the lease. Most work letters include a conflicts clause giving the work letter priority over the main lease on anything related to construction. That hierarchy matters because the two documents are often drafted at different times, sometimes by different lawyers, and contradictions slip in.
The document also names the key players: the landlord’s project manager, the tenant’s authorized representative, and sometimes the general contractor or architect. These designations aren’t formalities. They control who can approve change orders, sign off on inspections, and authorize payments. Naming the wrong person can stall the project for weeks when a fast decision is needed.
Scope: Shell Conditions and the Split of Work
Every work letter begins by defining what the tenant is getting before any construction starts. The baseline is usually a shell condition, and the difference between a cold shell and a warm shell carries real cost weight. A cold shell is an empty box: concrete floors, unfinished walls, no HVAC, no lighting, no ceiling grid. A warm shell comes with basic mechanical systems in place, including climate control, lighting, and sometimes a finished ceiling. The gap between those starting points can represent tens of thousands of dollars that someone has to absorb.
From that baseline, the work letter splits responsibilities. Landlord’s work covers building systems and structural elements the landlord agrees to deliver, which often includes bringing plumbing and electrical to specified stub-out points, installing fire suppression, and meeting code for occupancy. Tenant’s work covers what makes the space specific to the business: interior partitions, specialty electrical for equipment, flooring, paint, and custom finishes.
Specifications deserve close attention. “Building standard finishes” means nothing without specifics. The work letter should identify the exact grade of drywall, the fire rating of partitions, the acoustic performance of ceiling tiles, and the capacity of electrical circuits. Vague descriptions invite disputes when the landlord installs the cheapest qualifying option and the tenant expected better.
The Money: Allowance, Overages, and Fees
The tenant improvement allowance is the landlord’s financial contribution to the build-out, usually expressed as a dollar amount per rentable square foot. Size depends on the market, the lease term, the tenant’s creditworthiness, and how badly the landlord wants the deal. In strong markets with low vacancy, allowances shrink. Where landlords are competing for tenants, they grow. The allowance is never a gift; the landlord recovers it through the rent structure over the term.
The allowance spends across two categories. Hard costs cover physical construction: framing, drywall, flooring, electrical, plumbing, HVAC modifications, and permanent fixtures. Soft costs cover design and process: architectural fees (commonly 5% to 15% of construction costs), permit filing fees, engineering consultants, and legal review of construction contracts. The work letter should specify which expense categories qualify, because landlords and tenants routinely disagree about whether furniture, cabling, or signage counts.
When construction exceeds the allowance, the tenant pays the overage, and the mechanics vary. Some work letters demand the full overage upfront, which protects the landlord but strains tenant cash flow. Others tie payments to construction milestones. A few landlords will amortize the overage into rent at an agreed interest rate, which effectively turns the overage into a loan. The work letter should be explicit about which mechanism applies.
Landlords routinely charge a construction management fee for overseeing the build-out, typically 3% to 5% of total project costs. The fee usually applies even when the tenant’s own contractor is doing the work, on the theory that the landlord’s team still coordinates building access, reviews plans, and monitors compliance. Tenants with leverage sometimes negotiate the fee down or cap it at a fixed amount. If unused allowance remains after construction, the work letter decides whether the tenant receives a rent credit or the surplus simply disappears. Most landlords resist credits.
When Rent Starts: Substantial Completion and Punch Lists
Substantial completion is the most consequential milestone in the entire document, because it typically triggers the tenant’s obligation to start paying rent. The space is substantially complete when the tenant can move in and conduct business, even if minor items remain. Those remaining items go on a punch list: a detailed inventory of incomplete or defective work the contractor must finish without materially interfering with operations.
The definition deserves careful drafting. A well-written work letter ties substantial completion to two conditions: the physical work is done except for punch list items, and the local authority has issued permission for occupancy. If either condition isn’t met, the rent clock doesn’t start. Disputes about whether substantial completion has occurred are common, and many work letters give the landlord’s architect final say. Tenants should push for joint determination or independent arbitration instead.
Punch list work should carry its own deadline, typically 30 to 60 days after substantial completion. Without a deadline, contractors have little incentive to come back and finish the small items once the tenant is already in and paying rent.
Change Orders and Delays
No construction project proceeds exactly as drawn. Change orders are the formal mechanism for modifying scope, materials, or timeline after work begins. The work letter should specify who can authorize a change order (usually the designated representatives named in the document), the approval process, and how cost adjustments get handled. Most work letters require written approval from both parties. Verbal approvals produce disputes about whether a change was authorized and what it was supposed to cost.
Delays are where work letters most often fail tenants. If the landlord is responsible for construction and delivers late, the tenant needs contractual remedies already in place. The strongest protection is day-for-day rent abatement: one additional day of free rent for every day of late delivery. Some tenants negotiate escalating penalties, with abatement increasing to one-and-a-half or two days per day of delay beyond 30, 60, or 90 days. Without these provisions, a tenant can end up paying rent on space it can’t occupy, because the lease fixed rent commencement to a calendar date rather than actual delivery.
Landlords will insist on exceptions for tenant-caused delays, like mid-construction plan changes, and for force majeure. Those exceptions are reasonable in principle, but tenants should cap force majeure extensions at a defined period, such as 60 or 90 days, rather than leaving the landlord an open-ended excuse.
Compliance Risks the Work Letter Should Allocate
ADA Alterations and Path of Travel
Under the Americans with Disabilities Act, any alteration to a commercial facility that affects how the space is used must be made so the altered portions are accessible to individuals with disabilities, to the maximum extent feasible.1Office of the Law Revision Counsel. 42 USC 12183 – New Construction and Alterations in Public Accommodations and Commercial Facilities If the alteration involves a primary function area such as an office floor, lobby, or customer service area, the path of travel to that area, including hallways, restrooms, and drinking fountains serving the area, must also be made accessible.
The cost obligation is capped: no more than 20% of the total alteration cost needs to go to path-of-travel upgrades. On a major build-out, 20% is still a serious number, and the work letter should state whether that cost comes from the TI allowance or lands on the landlord. Tenant alterations affecting only the tenant’s own space do not trigger accessibility obligations in landlord-controlled areas, as long as the landlord isn’t altering those areas independently.2U.S. Access Board. Chapter 2: Alterations and Additions
Asbestos and Hazardous Materials
In older buildings, renovation can disturb asbestos-containing materials, and federal law places the notification and abatement burden on the building owner or operator. Under the EPA’s NESHAP rules, the owner or operator must thoroughly inspect the space for asbestos before any renovation. If regulated asbestos-containing material exceeds roughly 260 linear feet on pipes or 160 square feet on other surfaces, the owner must notify the relevant agency at least 10 working days before stripping or removal begins.3eCFR. 40 CFR 61.145 – Standard for Demolition and Renovation
The work letter should allocate this risk clearly. In most deals, the landlord bears responsibility for pre-existing hazardous materials since the tenant had nothing to do with putting them there. If the work letter is silent, tenants can end up absorbing abatement costs that delay the project and blow the construction budget. State and local requirements can be stricter than the federal baseline, so the document should also assign responsibility for environmental permitting.4U.S. Environmental Protection Agency. Information for Owners and Managers of Buildings that Contain Asbestos
Lien Waivers
Before the landlord releases construction funds, the tenant will have to produce lien waivers at every payment milestone. A lien waiver is the contractor’s written confirmation that it has been paid and won’t file a mechanic’s lien against the property for the covered work. This matters to landlords because an unpaid contractor can attach a lien to the landlord’s building even though the tenant hired the contractor.
Two forms circulate. A conditional waiver releases lien rights only once the check actually clears. An unconditional waiver releases those rights immediately on signing, regardless of whether payment has arrived. Signing an unconditional waiver before confirming payment leaves a contractor with no recourse if the check bounces. Several states require waivers to follow a specific statutory form, and substantial deviations can make the waiver unenforceable. Lenders often drive these requirements: if the landlord financed the building, the lender may demand proof the property is lien-free before releasing construction draws, and that requirement flows down to every subcontractor on the job. Tenants should also read waiver forms carefully, because some release more than lien rights, including broad indemnification obligations or waivers of unresolved claims unrelated to the current payment.
Builder’s Risk Insurance and Waiver of Subrogation
The work letter should require builder’s risk insurance covering the full replacement cost of the project during construction, protecting against fire, weather damage, theft of materials, and similar losses. Coverage should name the landlord, tenant, general contractor, and subcontractors as insured parties, so a loss doesn’t trigger a chain of lawsuits over fault.
Equally important is a waiver of subrogation, which prevents one party’s insurer from suing the other party to recover a paid claim. Without the waiver, the landlord’s insurer could pay a fire damage claim and then sue the tenant’s contractor to recoup, defeating the point of everyone carrying insurance. The work letter should require both parties to obtain endorsements confirming the waiver is in effect. Some waiver provisions specify that if a party fails to maintain the required insurance, that party is treated as fully insured for purposes of the waiver, so an uninsured party can’t gain an advantage by letting coverage lapse.
Landlord Step-In Rights
Some work letters give the landlord the right to take over the tenant’s construction project if things go seriously wrong. These step-in rights typically trigger when the tenant’s contractor defaults, becomes insolvent, or commits a material breach threatening the project timeline or the building itself. Once triggered, the landlord can act as project manager, pay outstanding bills directly, hire replacement contractors, and finish the work at the tenant’s expense.
The tenant risk is loss of control and higher costs, since a replacement contractor brought in on short notice tends to charge a premium. If the work letter includes step-in rights, tenants should negotiate clear triggers, a notice and cure period before the landlord can act, and a requirement that the landlord use commercially reasonable efforts to limit additional costs.
Plans and Approvals
The work letter is only as good as the technical documents attached to it. The exhibit package should include architectural drawings showing floor plan, partition layout, door and window placement, and finish schedule, plus engineering specifications for mechanical, electrical, and plumbing systems to confirm the building infrastructure can support the tenant’s needs. These documents must be prepared by licensed professionals familiar with local building codes, and they become the legal standard against which the finished construction is measured.
Once plans are complete, the tenant submits them to the landlord for approval. Landlords generally take 10 to 15 business days to review and respond. The work letter should set a firm deadline and state whether silence counts as approval or rejection, because the practical consequences for the construction schedule are large either way. After landlord sign-off, the tenant secures building permits from local authorities. Starting construction without permits can result in stop-work orders, fines, and forced removal of unpermitted work. The build-out clock officially begins once the exhibit is signed and the permits are issued.
End of the Lease: Restoration and Trade Fixtures
The work letter should also address what happens to improvements when the lease ends. Restoration clauses require the tenant to return the space to its original condition, or to a specified standard, before handing back the keys. That can mean demolishing interior walls, removing all tenant-installed fixtures, stripping flooring to bare concrete, and repainting throughout.
The cost surprises tenants who didn’t think about it when they signed. Demolition and disposal of a full office build-out is expensive, and the obligation applies even if the tenant wasn’t the one who originally built the space out. If you assumed the lease through an assignment, you may still be responsible for removing the prior tenant’s improvements. Three strategies reduce the exposure. The first is securing the landlord’s agreement during lease negotiations to accept the space as-is at the end of the term, eliminating restoration. The second is carving out standard improvements like drywall partitions and ceiling grids that any future tenant would likely keep. The third is requiring the landlord to notify the tenant at least 12 to 18 months before expiration which improvements must be removed, so the work can be budgeted and scheduled.
Trade fixtures installed for business operations are generally the tenant’s to remove, as long as removal doesn’t damage the building structure. Equipment, shelving, specialty counters, and similar items typically qualify. The work letter should identify explicitly which items are trade fixtures and which become permanent improvements belonging to the landlord. Where the document is silent, courts look at factors like whether the item is physically attached to the building, whether removal would cause structural damage, and whether the parties discussed the item’s status during lease negotiations.
Tax Consequences Follow the Payment Structure
How improvements are paid for determines who gets the tax deduction, regardless of who manages the construction. If the landlord funds improvements directly, the landlord depreciates them. If the tenant pays, or if the landlord provides an allowance the tenant controls, the tenant claims depreciation. The work letter’s payment structure effectively assigns the tax benefit, which is worth discussing with a tax advisor before the deal closes.
Depreciation of Qualified Improvement Property
Most commercial interior build-outs qualify as qualified improvement property under federal tax law, which covers any improvement to the interior of a nonresidential building placed in service after the building itself was originally placed in service. The category excludes building enlargements, elevators, escalators, and changes to the building’s structural framework.5Office of the Law Revision Counsel. 26 USC 168 – Accelerated Cost Recovery System Qualifying improvements are depreciated over 15 years using the straight-line method under the general depreciation system.6Internal Revenue Service. Publication 946 (2025), How To Depreciate Property
For improvements placed in service in 2026, the bonus depreciation rate has phased down to 20%, meaning you can deduct 20% of the cost in the first year and depreciate the remainder over the standard 15-year period.5Office of the Law Revision Counsel. 26 USC 168 – Accelerated Cost Recovery System That’s a significant drop from the 100% bonus depreciation available from 2018 through 2022, and it changes the timing of the tax benefit. Businesses that elect out of the Section 163(j) interest deduction limitation must use the alternative depreciation system, which stretches the recovery period to 20 years.
Construction Allowance Exclusion for Retail Tenants
Tenants receiving a construction allowance from the landlord should know about the income exclusion under Section 110 of the Internal Revenue Code. If you lease retail space under a lease of 15 years or less and spend the entire allowance on qualified long-term real property improvements that revert to the landlord when the lease ends, the allowance is excluded from your gross income. The exclusion is capped at what you actually spend, so any unspent portion is taxable. This applies specifically to retail space, meaning tenants selling goods or services to the general public. Office tenants and industrial users don’t qualify for this exclusion.7Office of the Law Revision Counsel. 26 U.S. Code 110 – Qualified Lessee Construction Allowances for Short-Term Leases