Commercial Interior Fit-Out Checklist: Everything You Need to Know

A commercial interior fit-out is the most complex interior project most businesses undertake. Coordinating architecture, engineering, furnishings, technology, and installation timelines requires meticulous planning. One missed step, forgotten power points, unordered long-lead items, clashing infrastructure, costs thousands and delays opening.

Last updated: April 2026 · Reading time: 2 min

We've managed 200+ fit-outs across the North West. This checklist covers what matters, in order.

Phase 1: What Pre-Project Planning Do You Need? (Weeks -4 to 0)

Before you touch the building: Through our commercial design services, we help schools transform their spaces.

• Secure landlord consent and building lease review: Does your lease allow fit-out works? What approvals are needed?
• Budget confirmation: Fit-out costs typically run £1,200-£3,500 per sqm depending on specification. Confirm total.
• Project timeline: How long do you have? This drives everything else.
• Team assembly: Appoint a project manager (internal or external). Assign a budget holder.
• Consultant briefing: Architect, MEP engineer, structural engineer if needed. Agree fees and timelines.

This phase takes 4 weeks. Rushing it creates problems downstream.

Phase 2: How Do You Audit and Analyse the Existing Space? (Weeks 1-3)

Commission a measured survey of existing spaces:

• Floor plans to 1:100 scale: Accurate dimensions including ceiling heights, column positions, existing infrastructure
• Condition survey: Structural integrity, asbestos survey (pre-2000 buildings), electrical/mechanical condition
• Utilities audit: Location of incoming power, water, gas, drainage, data cables, HVAC
• Building regulation compliance: Fire exits, means of egress, disabled access requirements
• Site photography: Visual record of existing conditions

Budget £2,000-£5,000 for this. Inaccurate survey data costs far more downstream.

Phase 3: How Do You Develop the Design Brief? (Weeks 3-6)

Define what you actually need:

• Space programme: List all rooms, their purpose, occupancy, equipment requirements. Area allocations.
• Adjacency mapping: Which spaces must be near each other? Reception near entrance? Meeting rooms away from noise?
• Specification of finishes: Flooring, walls, ceilings, colour palette, branding integration
• Technology requirements: Wifi, data points, power outlet locations, AV systems, security
• Furniture and equipment list: Every desk, chair, cabinet, appliance needed. Brands, colours, quantities.
• Accessibility requirements: Wheelchair access, grab rails, accessible toilets, accessible parking if applicable

This is decision-heavy. Allow time for stakeholder input. The decisions made here drive all downstream costs.

Phase 4: How Should You Allocate Budget and Plan Costs? (Weeks 6-8)

Allocate budget across categories:

• Architectural works (30-40%): Structural changes, partitions, finishes, paint
• MEP systems (20-25%): Electrical, plumbing, HVAC, fire safety systems
• Furniture (20-30%): Desks, chairs, storage, fitments
• Technology infrastructure (5-10%): Power distribution, data cabling, IT equipment
• Professional fees (8-12%): Design, project management, building control
• Contingency (5-10%): Unexpected conditions (asbestos discovery, structural issues, supply delays)

This breakdown prevents over-spending in one category at expense of others. Adjust based on your priorities.

Phase 5: What Does the Detailed Design Phase Include? (Weeks 8-14)

Architect produces detailed drawings:

• Floor plans at 1:50 scale: All partitions, doors, windows, dimensions, references to details
• Reflected ceiling plans: Lighting, air conditioning, sprinkler positions, finishes
• Elevation drawings: Wall treatments, height details, fitments
• Detail sections: How corners, transitions, and complex areas are built
• Specifications: Written description of every material and system. Used by contractors for pricing.
• 3D visualisation: Renders showing the completed space. Essential for stakeholder buy-in and identifying design issues early.

Review the visualisation carefully. This is your chance to catch design problems before builders arrive.

Phase 6: When Should You Specify and Order Furniture? (Weeks 12-16)

This overlaps with design. Long-lead items must be ordered early:

• Prepare furniture schedule: Every piece, quantity, finish, delivery date
• Order long-lead items immediately: Custom furniture, built-in cabinetry, specialist seating. Typical lead time 8-14 weeks.
• Confirm delivery dates: Furniture must arrive after finishes are complete but before handover
• Arrange storage if needed: If the site can't accommodate delivered items, arrange interim storage
• Specify assembly and installation: Who installs? Supplier or your contractor?

Forgotten furniture orders are the number one cause of delays. Build in 2-week buffer for delivery delays: they're common.

Phase 7: How Do You Select the Right Contractor? (Weeks 14-20)

Invite tenders from qualified contractors:

• Provide detailed specifications and drawings: Ambiguity results in incomplete quotes and disputes
• Request itemised quotes: Not lump sums. You need to see what drives cost.
• Require timeline and method statements: How will they sequence work? How long?
• Check references: Speak to previous clients about quality, timekeeping, budget control
• Assess capability: Can they handle your project size and complexity?

Don't choose based on price alone. A cheap quote that misses specifications or delivers poor quality costs more than a fair quote from a competent contractor.

Phase 8: How Do You Coordinate Infrastructure Before Construction? (Weeks 20-24)

Before construction begins, coordinate infrastructure:

• M&E coordination meeting: Mechanical, electrical, plumbing, structural, architectural teams review how systems coordinate in 3D
• IT infrastructure planning: Where do data cables run? Where are network switches? What's the bandwidth requirement?
• Temporary facilities if needed: If the building remains occupied, plan dust control, access routes, welfare facilities for workers
• Building control notification: Structural, fire safety, and accessibility aspects need approval before work starts
• Utility disconnection/reconnection schedule: When are water, power, data being isolated and restored?

This coordination prevents clashes that delay work and cost money to rectify.

Phase 9: What Should You Manage During Construction? (Weeks 24-52+)

The contractor builds. Your project manager oversees:

• Weekly site meetings: Review progress, identify issues, confirm schedule
• Quality checks: Inspect finishes, systems, furniture installation for compliance
• Change control: If you want to change anything, document it. Track cost impact.
• Safety compliance: Ensure the site maintains health and safety standards
• Defect tracking: Document anything that doesn't meet specification. Contractor fixes before handover.

Site meetings prevent surprises. Stay engaged.

Phase 10: How Do You Handle Snagging and Defect Resolution? (Final 2-4 Weeks)

Before you occupy, produce a snagging list:

• Walk the entire space: Look for paint runs, uneven finishes, loose fixtures, non-functioning systems
• Test all systems: Lighting, power, HVAC, water, fire safety systems. Document anything that doesn't work.
• Check furniture installation: All pieces present? Correctly assembled? Damage or defects?
• Create a prioritised defects list: Critical (safety, non-functional), Important (affects use), Minor (cosmetic)
• Agree timelines for rectification: Critical issues fixed before occupancy; others within 2 weeks

Don't ignore defects. Small issues compound. A paint run in one corner creates a shortcut mentality where corner-cutting spreads.

Phase 11: What Documentation Should You Receive at Handover? (Final Week)

Before occupancy, ensure you receive:

• As-built drawings: Marked-up plans showing what was actually built (often differs slightly from design)
• Operation manuals: For every system, HVAC, lighting controls, security, access systems
• Warranties and guarantees: Builder's warranty (typically 1 year), product warranties (2-10 years depending on item)
• Maintenance schedules: When systems need servicing (HVAC annually, boilers annually, etc.)
• Building regulation completion certificate: Evidence that all works comply with building regulations
• Key and access information: All keys, access card distribution, emergency contact numbers

Keep these documents. You'll need them for future maintenance and eventual refurbishment.

Phase 12: What Post-Handover Aftercare Is Required? (Months 1-12)

Stay in touch with your contractor and suppliers:

• Report any defects within warranty period: Contractor is obligated to fix
• Schedule system commissioning: HVAC, fire systems, access systems need professional commissioning
• Monitor performance: Is the space working as designed? Feeding back issues helps future projects

The fit-out isn't finished until systems are commissioned and staff are trained on operation.