You've found an office.

The location works. The floor area looks about right. The rent fits the numbers. There's good natural light and, with a little imagination, you can already picture your team working there.

So, is it time to sign the lease?

Not necessarily.

Before committing to a new workplace, there's another question worth asking:

Can this building actually become the workplace your organisation needs, within the budget and timescale you have available?

That's a different question entirely.

Two offices with similar floor areas and rents can require very different levels of investment before they're ready for occupation. One may already have suitable mechanical and electrical services, good connectivity and a layout that can be adapted relatively easily.

Another might need significant alterations to HVAC, lighting, power, data, ceilings, partitions, meeting facilities and other building services before the first desk arrives.

The difference may not be obvious during a property viewing.

That's why office fit out planning should ideally begin before the lease is signed, rather than afterwards.

Involving an experienced design and build contractor or fit out contractor while you're still assessing potential premises can help you look beyond the empty floorplate and understand what the building could realistically become.

Because the best time to discover that an office is difficult or expensive to fit out is before you've committed to it.

In This Guide

Why office fit out planning should begin before the lease
Start with the business, not the building
Will your team actually fit?
Space planning before you commit
CAT A, CAT B and Shell & Core: understand what you're getting
Check the mechanical and electrical services
Heating, cooling and ventilation
Power, data and connectivity
Lighting and ceilings
Meeting rooms and acoustics
Accessibility and employee experience
Building access and fit out logistics
Landlord requirements and restrictions
Fit out costs: look beyond the rent
Can the office support future growth?
Sustainability and what can be retained
Can the fit out be completed before your move date?
Don't forget the office you're leaving
What should a fit out contractor assess?
Comparing shortlisted offices
Questions to ask before signing
FAQs
Your next step

Why Office Fit Out Planning Should Begin Before the Lease

The traditional sequence can look something like this:

Find office → negotiate lease → sign → appoint fit out contractor → start designing.

There's an obvious problem.

By the time your office design team properly assesses the premises, you've already committed to the building. A potentially better sequence could be:

Understand workplace requirements → shortlist offices → assess fit-out potential → compare options → commit to premises → develop design → deliver fit out.

It doesn't mean designing three complete offices before choosing one. It means carrying out enough due diligence to understand whether the space can realistically support your organisation.

That can uncover questions around:

capacity
layout
building services
meeting requirements
power and data
HVAC
accessibility
fit out specification
landlord restrictions
delivery access
programme
future flexibility
likely investment

Some buildings will present straightforward answers. Others won't. Either way, it is better to know before the lease is signed.

Start With the Business, Not the Building

Before comparing floorplates, establish what you're actually trying to accommodate.

How many employees do you have now?
How many might you have in three years?
How often are people in the office?
Which days are busiest?
Which teams need to work together?
How many meetings take place?
How many are hybrid?
Do employees need quiet space?
Are confidential conversations common?
Do clients visit?
What storage is required?
Are there specialist technology requirements?
Does the business expect to grow?

These questions form the basis of an effective office fit out brief.

Without them, it's very easy to judge prospective offices almost entirely on square footage and appearance.

But a 10,000 sq ft workplace that is poorly configured may be less useful than a smaller floorplate with better proportions, services and flexibility.

The objective isn't simply to find enough space. It's to find the right space.

Will Your Team Actually Fit?

This sounds obvious. But calculating workplace capacity isn't simply:

Floor area ÷ desk size = number of employees.

People need more than desks. Depending on the organisation, your new office may need:

workstations
meeting rooms
boardrooms
quiet rooms
acoustic booths
collaboration areas
reception
visitor facilities
breakout space
kitchen facilities
storage
print areas
circulation
welfare facilities
accessible facilities
technology and support spaces

Hybrid working adds another layer.

An organisation may need fewer permanently allocated desks but considerably more meeting, collaboration and video-call space.

That's why capacity should be tested through office space planning, rather than estimated from the headline floor area alone.

Space Planning Before You Commit

An early test-fit can be one of the most useful exercises when comparing potential premises.

A test-fit is not the finished office design. It's an initial space planning exercise used to establish whether the floorplate can accommodate your core requirements.

For example:

Can we accommodate the required number of people?
Where could meeting rooms sit?
Does the floorplate allow teams to be positioned sensibly?
Could client-facing spaces be separated from working areas?
Can we provide enough quiet rooms?
Where might the kitchen and breakout facilities go?
Does the layout create excessive dead space?
Can the workplace adapt if headcount changes?
If you're choosing between two buildings, this exercise can reveal differences that weren't obvious during the viewing.

One office may be slightly smaller but substantially more efficient.

Another may have awkward columns, poor circulation or fixed building elements that reduce its usable potential.This is where involving an office design and build contractor early can provide genuine commercial value.

You're not simply asking:

"Can we fit 100 desks?"

You're asking:

"Can this building support the way our organisation needs to work?"

CAT A, CAT B and Shell & Core: Understand What You're Getting

Commercial premises can be handed over in very different conditions. Understanding the starting specification is essential because it affects the scope and cost of the eventual office fit out.

Shell & Core

A Shell & Core space is generally a relatively unfinished internal environment.

The building structure and core elements exist, but the tenant space may require substantial work before it becomes an operational workplace.

CAT A

A CAT A office fit out typically provides a basic landlord finish that may include elements such as raised access flooring, suspended ceilings, lighting and mechanical services.

However, specifications vary.

Never assume that "CAT A" means exactly the same thing in every building.

CAT A+

CAT A+ has become increasingly common in parts of the commercial property market.

It generally provides a more developed workplace than traditional CAT A, potentially incorporating furniture, meeting areas, kitchens and other elements.

Again, specifications vary considerably.

CAT B

A CAT B office fit out transforms the space around the tenant's actual requirements.

This is where the workplace takes shape through office design, partitions, meeting rooms, furniture, finishes, branding, technology, kitchens, specialist lighting and other requirements.

Before committing to premises, establish exactly what the landlord is providing and exactly what you will need to add.

For a more detailed explanation, link here to CAT A vs CAT B Office Fit Out: What's the Difference?

Look Up: What Is Happening With the Ceiling?

People naturally look around when viewing an office. It's worth looking up too.The ceiling can influence acoustics, lighting, ventilation, fire systems and the overall office design.

Ask:

What type of ceiling is installed?
Is it in good condition?
Where are the existing lights?
Where are the air-conditioning units?
Where are the ventilation grilles?
How easily can these elements be adapted to suit a new layout?

If you're planning multiple meeting rooms, offices or enclosed spaces, existing services may need repositioning or extending.

A layout isn't simply lines drawn on a floor plan. Everything above those lines needs to work too.

Mechanical and Electrical Services: The Part You Can't Ignore

Some of the most important fit-out considerations are also among the least visually exciting.

Mechanical and electrical services — M&E — can have a significant influence on the viability, cost and complexity of a commercial office fit out.

This can include:

heating
cooling
ventilation
lighting
power
distribution boards
fire systems
controls
water
drainage
data infrastructure

Existing systems need to be understood in relation to the proposed workplace layout.

For example, turning an open-plan area into several enclosed meeting rooms can affect ventilation, cooling, lighting and fire-system requirements.

Adding more people can alter loads.

A new kitchen may introduce additional electrical and plumbing requirements.

A visually attractive empty office doesn't tell you whether its building services are suitable for your intended use.

That's why technical assessment matters.

Heating, Cooling and Ventilation

Temperature problems can undermine an otherwise excellent workplace.

Before committing to a building, understand what heating, cooling and ventilation systems are installed and how they operate.

Consider:

Is the system shared or dedicated?
How is it zoned?
Can different areas be controlled independently?
Will the system work with the proposed meeting-room layout?
What condition is the equipment in?
Are there landlord restrictions around modifications?
Can additional capacity be introduced if required?

The answers may influence both office design and fit out cost.

It is much easier to account for those requirements during early planning than discover them after the workplace layout has been agreed.

Power, Data and Connectivity

Modern workplaces rely heavily on connectivity. So don't leave it until move-in week.

Consider:

incoming connectivity
Wi-Fi requirements
data cabling
floor boxes
desk power
charging
meeting-room technology
AV
screens
video conferencing
access control
server or communications requirements
resilience for business-critical systems

A new office fit out provides an opportunity to build technology into the workplace rather than bolt it on afterwards.Your IT requirements should therefore form part of the brief given to your fit out contractor.

Meeting Rooms Need More Than Four Walls

Meeting rooms are frequently one of the biggest pressure points in modern offices and hybrid working has made their performance more complicated.

A good meeting room may need to consider:

size
occupancy
acoustics
privacy
ventilation
cooling
lighting
AV
displays
cameras
microphones
power
data
accessibility

A floorplate may appear capable of accommodating six meeting rooms.The more useful question is whether those six rooms can actually be made comfortable and functional.

Again, that is why early office design and space planning matters.

Don't Forget Acoustics

Acoustics can be difficult to judge in an empty office.Empty spaces naturally behave differently once furniture, partitions and people are introduced.

Consider the relationship between:

Open-plan work areas.
Meeting rooms.
Quiet zones.
Kitchens.
Breakout spaces.
Collaboration areas.
Confidential rooms.
Video-call spaces.

The aim isn't to make the workplace silent. It's to manage different activities so they can coexist. Acoustic partitions, ceiling treatments, wall finishes, furniture, pods and layout planning can all contribute.

But the starting point is understanding what activities the workplace needs to support.

Accessibility Should Be Considered From the Start

Accessibility isn't something to add once the layout has been designed. Consider how employees and visitors will move through and use the workplace.

That includes entrances, circulation, doors, meeting rooms, welfare facilities, furniture and access to different workplace settings.

Inclusive office design is easier to achieve when it is considered from the beginning rather than treated as a later adjustment.

Can You Actually Get the Fit Out Into the Building?

Sometimes the challenge isn't what you're installing.It's getting it there.

For multi-tenanted buildings or central locations, check:

loading access
delivery restrictions
lift sizes
lift availability
stair access
parking
contractor access
security procedures
working-hour restrictions
noise restrictions
waste removal
material storage
neighbour considerations

A large boardroom table, acoustic pod or specialist piece of equipment is only useful if it can physically reach its destination. Logistics can also affect the office fit out programme, particularly where deliveries or noisy works are restricted to certain hours.

What Does the Landlord Allow?

Before planning alterations, understand the lease and landlord requirements. Depending on the property and proposed works, this may involve a licence to alter or other approvals.

Your legal and property advisers should guide you on the lease itself. From a fit-out perspective, however, it is useful to understand:

What alterations are permitted?
What information needs to be submitted?
Are there restrictions around HVAC?
Can floors or ceilings be altered?
What are the requirements around fire systems?
Are there approved contractors for particular services?
What are the working-hour restrictions?
What must be reinstated when the lease ends?

The answers can affect design, cost and programme.

The Rent Isn't the Cost of the Office

This is one of the most important points when comparing buildings.

The headline rent is only one part of the commercial decision.

A prospective workplace may also involve:

office fit out
office design
furniture
M&E alterations
IT and AV
professional fees
landlord requirements
moving costs
temporary arrangements
dilapidations at the existing office
future reinstatement obligations

This means the cheapest office to rent isn't automatically the cheapest office to occupy. Consider two hypothetical buildings.

Office A has the lower rent but requires substantial M&E alterations and significant changes before it can support your organisation.

Office B costs slightly more but already has suitable services and a floorplate that accommodates your requirements efficiently.

Looking only at rent could lead you towards the wrong conclusion.

A better question is:

What will each option realistically cost us to turn into the workplace we need?

If you're beginning to establish likely project investment, link here to How Much Does an Office Fit Out Cost?

Can the Office Grow With You?

Signing a lease for a workplace that only just accommodates today's business can create problems surprisingly quickly. Consider your likely position in three to five years.

Could headcount increase?

Could teams change?

Might you introduce different working patterns?

Could meeting demand increase?

Might departments need to expand or contract?

A degree of flexibility can be built into the office fit out.

That might include:

adaptable furniture
modular meeting spaces
flexible collaboration areas
demountable partitions
movable walls
multi-purpose spaces
appropriate power and data provision

You can't predict every change. But you can avoid designing an office that only works one way.

What Can You Reuse?

If you're moving from an existing office, not everything necessarily needs replacing. Furniture, chairs, storage, AV equipment and other assets may be capable of moving with you.

Understanding what can be reused before the new CAT B fit out is designed can help avoid unnecessary replacement.

It can also influence the design.

If 80 existing desks are moving with you, the new workplace needs to accommodate those desks rather than a theoretical furniture specification.

Reuse should therefore be part of the brief, not an afterthought.

Can You Complete the Fit Out Before You Need to Move?

Finding the right building is only half the challenge.

It has to be ready when you need it.

An office fit out programme can include:

Brief development
Surveys
Space planning
Office design
Landlord approvals
Technical design
Procurement
Construction
Furniture and technology
Testing and commissioning
Move-in

If you have a fixed lease expiry at your existing office, the programme needs to work backwards from that date.

Leaving the fit out conversation too late can reduce options, create unnecessary pressure and potentially increase cost.

For a more detailed breakdown, link here to How Long Does an Office Fit Out Take? Timeline Explained.

Don't Forget the Office You're Leaving

While everyone is thinking about the new workplace, somebody also needs to think about the old one. Your outgoing lease may contain requirements around reinstatement or dilapidations.

That could involve:

removing partitions
removing branding
making good finishes
reinstating services
repairing damage
removing furniture
returning the premises to an agreed condition

This should be considered alongside the new office programme.

You don't want to discover that your project team is simultaneously trying to move employees, complete a new office fit out and deal with unexpected reinstatement works at the old premises.

Plan both sides of the move.

What Should a Fit Out Contractor Assess Before You Sign?

You don't necessarily need a fully appointed contractor while you're still property hunting. But early input from an experienced design and build contractor can be valuable.

Depending on the stage of your search, they may be able to help assess:

Space

Can the floorplate accommodate your people and workplace requirements?

Layout

Are the shape, core, columns and circulation conducive to an efficient design?

Building Services

Are HVAC, lighting, power and other services suitable or likely to require significant alteration?

Technology

Can the building support your data, AV and connectivity requirements?

Fit Out Specification

What is the landlord actually providing?

Practicality

Are there access or construction constraints?

Programme

Can the required work realistically be completed before your desired occupation date?

Investment

What level of office fit out is likely to be required?

That information gives you a much better basis for comparing shortlisted buildings.

Comparing Two Offices? Don't Just Compare the Rent

A simple assessment can help bring structure to the decision.

Question	Office A	Office B
Does the location work?
Can it accommodate current headcount?
Can it accommodate growth?
Does the floorplate support our required layout?
Is the existing specification suitable?
Are the HVAC systems appropriate?
Is power/data provision suitable?
Can meeting-room requirements be achieved?
Does it support hybrid working?
Is accessibility suitable?
Are there major landlord restrictions?
Is construction access practical?
Can the fit out meet our programme?
What level of fit out investment is required?
What is the overall occupation picture?

The purpose isn't necessarily to generate a mathematical winner. It's to expose differences before they become expensive surprises.

15 Questions to Ask Before Signing a New Office Lease

Before committing to the premises, try to answer these:

Can the space accommodate our current team comfortably?
Can it support our expected growth?
Does the floorplate work for the way our teams operate?
What fit out specification is the landlord providing?
What will we need to add through our CAT B office fit out?
Are the heating, cooling and ventilation systems suitable?
Is there sufficient electrical capacity?
Can our data and connectivity requirements be achieved?
Can we create the meeting rooms and collaboration spaces we need?
Are there accessibility considerations we need to address?
What landlord approvals will be required?
Are there restrictions on construction activities?
Can furniture and materials be delivered easily?
Can the office fit out be completed before our move date?
What is the realistic total investment required to turn this property into our workplace?

If several of those questions remain unanswered, that's a good reason to investigate further before signing.

Download: New Office Fit-Out Suitability Checklist

If you're comparing potential offices, it can be difficult to remember what you saw once you've visited several buildings.

That's why we've created a practical New Office Fit-Out Suitability Checklist.

Take it to property viewings and use it to compare:

space
layout
future growth
CAT A / CAT B specification
HVAC
power
data
meeting-room potential
natural light
acoustics
accessibility
building access
landlord restrictions
fit out complexity
programme
likely project requirements

The aim isn't to replace professional property, legal or technical advice.

It's to help you ask better questions before making one of the biggest workplace decisions your organisation will make.

Download the New Office Fit-Out Suitability Checklist.

Frequently Asked Questions

When should I appoint an office fit out contractor?

You don't necessarily need to formally appoint a contractor before choosing premises, but speaking to an experienced office fit out contractor during the property-search stage can be valuable.

Early workplace and technical input can help assess whether shortlisted offices can support your space, design, programme and budget requirements.

Should I have a space plan before signing an office lease?

An initial test-fit or space plan can be extremely useful.

It doesn't need to be the final office design. Its purpose is to establish whether the floorplate can accommodate your people, meeting requirements, collaboration areas, support spaces and future growth.

What is a CAT B office fit out?

A CAT B office fit out transforms a commercial space around the requirements of the tenant.

It can include partitions, meeting rooms, flooring, specialist lighting, furniture, kitchens, branding, AV, data and other elements needed to create the finished workplace.

What's the difference between CAT A and CAT B?

CAT A generally describes the landlord's basic internal specification, while CAT B creates the tenant-specific workplace.

However, specifications vary between buildings, so always establish exactly what is included rather than relying on the label alone.

How much does an office fit out cost?

Office fit out costs depend on factors including the existing condition of the building, size, specification, M&E requirements, furniture, technology, design complexity and programme.

A survey and clear project brief provide a more useful basis for budgeting than a generic square-foot figure alone.

How long does an office fit out take?

Programme depends on project size and complexity as well as design, approvals, procurement, construction and commissioning.

Planning should therefore begin well before the intended move date.

Can a design and build contractor help us compare potential offices?

Yes. A design and build contractor can potentially provide workplace, space-planning and technical input while premises are being considered.

This can help identify opportunities and potential fit-out challenges before the business commits to a particular property.

What should we bring to the first meeting with a fit out contractor?

Useful information includes your current and anticipated headcount, working patterns, property details, existing plans, desired move date, workplace requirements, technology needs, budget expectations and any known landlord information.

You don't need to have every answer.

Part of the contractor's role should be helping you identify the questions that still need answering.

The Best Office Isn't Always the Most Obvious One

Property decisions involve many considerations that sit outside the fit-out itself.

Location matters.
Rent matters.
Lease terms matter.
Transport matters.
Local amenities matter.

But so does the building's ability to become a workplace that supports your organisation.

A beautiful reception won't compensate for an office that can't comfortably accommodate your team.
A lower rent may lose some of its appeal if extensive building-service alterations are required.
An extra 2,000 square feet isn't necessarily valuable if the floorplate uses it inefficiently.

That's why the office fit out conversation is worth having earlier.Not after the building has been chosen but before.

Looking at New Offices? Bring the Fit Out Conversation Forward

If you're considering a new workplace in London, Surrey, Sussex, Kent, Berkshire or elsewhere across the South East, you don't have to wait until the lease is signed before starting the fit-out conversation.

TB Fit Out works with organisations as a design and build contractor and office fit out contractor, bringing together workplace strategy, office design, space planning, CAT A and CAT B fit out, M&E, furniture, data, AV and project delivery.

If you've shortlisted potential premises, we can help you look beyond the empty floorplate and start exploring what each space could realistically become.

Because choosing an office isn't simply about finding somewhere your business can occupy.

It's about finding somewhere your business can work.

Book a complimentary workspace audit or talk to us about your shortlisted premises before you commit.

Final Thought

A property viewing tells you what an office is today.

Good office fit out planning helps you understand what it could become. Before signing the lease, take time to look beyond the floor area, rent and location.

Think about your people.

Your growth.
Your technology.
Your meetings.
Your building services.
Your budget.
Your programme.
And the way you want the organisation to work in the years ahead.

Then ask the question that really matters:

Can this building become the workplace our business actually needs?

If you can answer that confidently before you commit, you're starting your office fit out from a much stronger position.

Book a workplace Audit

Before You Sign the Lease: Is Your New Office Actually Fit-Out Ready?