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Commercial Lease Law

Tenant Fit-Out UK — Commercial Landlord's Guide to Approvals, CDM, and Reinstatement

Commercial tenant fit-out works engage the landlord's interests on multiple fronts: the lease alterations covenant, CDM 2015 obligations, Building Safety Act 2022 (for higher-risk buildings), reinstatement liability at lease end, and the building's EPC and sustainability ratings. Category A (base build: raised floor, suspended ceiling, HVAC distribution, core WCs, primary electrical supply) vs Category B (occupier fit-out: partitions, meeting rooms, kitchen, bespoke finishes, furniture). Qualified covenant against alterations (s.19(2) LTA 1927: implied reasonableness; no LTA 1988 statutory procedure for alterations). Licence for alterations: must be a deed executed before works start; appended drawings; conditions of consent (statutory consents, contractor approval, CDM notifications); structural engineer's certificate on completion; reinstatement obligation (which elements must go and which can stay). CDM 2015: tenant as CDM client; Principal Designer and Principal Contractor appointment; F10 HSE notification; Health and Safety File delivered to landlord on completion. Reinstatement: without an express reinstatement obligation in the licence, the tenant has no obligation to remove alterations; specify at licence stage which elements must be reinstated; require reinstatement programme in final year of term; failure to reinstate is an additional dilapidations head outside s.18 LTA 1927 cap in some cases. Scotland: s.4 Law Reform (Miscellaneous Provisions)(Scotland) Act 1994; CDM 2015 applies.

11 min readUpdated 7 June 2026Last reviewed: 17 May 2026tenant-fit-outlicence-for-alterationscdm-2015-commercialreinstatement-alterations

Category A vs B Fit-Out and the Licence for Alterations

Category A (Cat A) is the landlord's base build: raised floor, suspended ceiling, HVAC distribution, core WCs, primary electrical supply. Category B (Cat B) is the tenant's occupational fit-out: partitions, meeting rooms, reception, kitchen, bespoke lighting, furniture. Shell-and-core: landlord delivers only the structural shell; the tenant carries out even more extensive works. Lease alterations covenant: absolute prohibition (valid — no reasonableness test for structural works); qualified covenant (s.19(2) LTA 1927 — reasonableness implied; no LTA 1988 statutory procedure for alterations, unlike assignment); internal non-structural alterations often absolutely permitted or notification only. Licence for alterations: must be a deed executed before works start (retrospective consent does not cure the breach); append the approved drawings (works outside those drawings are outside the consent); conditions precedent (statutory consents before start; contractor approval; RAMS review; CDM notifications); inspection rights; structural engineer's certificate on completion; Health and Safety File delivery on completion. Building Safety Act 2022 (HRBs): for higher-risk buildings (18m+ or 7+ storeys; 2+ residential units), major fit-out works may require notification to the Building Safety Regulator.

CDM 2015 and Reinstatement Obligations

CDM 2015: tenant is typically the CDM client for a Cat B fit-out; responsible for appointing Principal Designer (pre-construction health and safety coordination) and Principal Contractor (construction phase safety); F10 HSE notification where the project exceeds 30 working days with more than 20 workers simultaneously or 500 person days; Health and Safety File (O&M information, as-built drawings, test certificates) delivered to landlord on completion. Where the landlord is commissioning any concurrent works, the landlord has its own CDM client duties. Reinstatement: without an express provision in the licence, the tenant has no obligation to remove alterations beyond the general yielding-up covenant; specify in the licence which elements must be reinstated (mezzanines, server rooms, raised floors) and which can be retained; require reinstatement programme in the final year of the term; approve before tenant commences reinstatement; failure to reinstate per the licence is an additional dilapidations head — separately quantified; the s.18 LTA 1927 diminution-in-value cap on dilapidations may not limit reinstatement of alterations claims. Fit-out guide: append a landlord's fit-out guide to the lease specifying Cat B standards, sustainable materials, reinstatement requirements, and BIM data delivery — reduces licence negotiation friction for each set of works.

Frequently asked questions

Does a commercial tenant need the landlord's permission to fit out?+

It depends on the lease's alterations covenant. Internal non-structural alterations are often permitted absolutely or with notice. Structural alterations almost always require express landlord consent and a formal licence for alterations executed as a deed before works start.

Who is the CDM client for a commercial tenant fit-out?+

In a tenant fit-out, the tenant is typically the CDM client — responsible for appointing the Principal Designer and Principal Contractor, providing F10 HSE notification where required, and delivering a Health and Safety File to the landlord on completion. The licence for alterations should confirm this and require delivery of the H&S File.

Can a landlord require a commercial tenant to reinstate fit-out works at lease end?+

Yes — but only if the licence for alterations expressly requires it. Without an express reinstatement obligation, the tenant has no duty to remove alterations beyond what the general repairing and yielding up covenant provides. Landlords should specify at licence stage which elements must be reinstated.

Found a gap or disagree with something?

Reply to any LetSafe email or write to Richard@letsafeuk.co.uk. We rewrite guides when we get something wrong, the sooner we hear, the sooner we fix it.

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