How to Budget for a Spa Refurbishment: A Comprehensive Guide

Refurbishment is one of the most significant commercial decisions a spa or hotel operator will make. Get the budgeting right from the outset and you have a clear roadmap — a way to sequence decisions, manage expectations, and protect your margins throughout the project. Get it wrong, and you face the two scenarios that derail more refurbishments than any other: running out of contingency mid-build, or under-investing in the areas that actually drive guest revenue.

This guide is written for spa directors, hotel managers, and commercial property operators who are at the early stages of planning a refurbishment. It covers what actually drives cost variation, how to think about budget by project type, why wet areas are in a category of their own, what operators consistently underestimate, the essential requirements for designing a spa, how to approach phasing, and what a well-executed refurbishment should deliver commercially to make the spa refurbishment a success.

Not sure where your project sits in the development process? Our five-stage guide to spa development walks you through the full journey from initial idea to completed project.

Why the same square footage can cost very different amounts

The most common frustration operators experience when getting early cost estimates is the breadth of the ranges. Quoted figures for spa refurbishment in the UK can vary by a factor of three or four for projects that appear superficially similar. This is not vagueness on the part of contractors. It reflects genuine variables that have an enormous bearing on final cost.

Scope of works is the primary driver. Cosmetic updates — new flooring, lighting, furniture, paint, soft furnishings — are relatively straightforward to cost and deliver. The moment you introduce structural changes, relocate drainage, alter ventilation systems, change a spa layout, or replace pool infrastructure, you move into a fundamentally different cost bracket. The distinction matters because operators sometimes discover mid-project that a seemingly cosmetic brief has structural implications. For example, a relaxation lounge redesign that requires moving a load-bearing wall, or a thermal suite upgrade that triggers ventilation replacement.

The condition of existing infrastructure is the second major variable, and the one most likely to produce budget surprises. Older buildings (particularly converted country houses, Victorian hotels, or facilities built before current building regulations) often contain mechanical and electrical systems that are incompatible with modern spa requirements. Discovering that the existing plant room cannot support a new pool filtration system, or that the electrical supply requires upgrading to power a new thermal suite, can add tens of thousands to a project that appeared straightforward on paper. This is why condition surveys conducted before design work begins are not optional. They are budget protection.

Specification level has a direct and significant impact on cost. Premium natural stone tiling, bespoke joinery, specialist spa lighting systems, and high-end equipment carry very different price tags to mid-range alternatives. For operators in the luxury segment, the case for premium specification is commercial as well as aesthetic — guests at five-star properties have calibrated expectations that cheaper finishes will not meet. For mid-market operators, value engineering in certain areas is entirely reasonable, provided it does not compromise the technical performance of wet areas or ventilation systems, where cutting costs reliably creates long-term problems.

Location influences labour costs. Projects in London and the South East carry a 20–30% labour premium over regional projects — a well-established pattern across all types of commercial construction. [Source: RICS regional cost data; All Well Property Services refurbishment cost analysis, 2025]

Building constraints affect both programme and cost. Listed buildings require Listed Building Consent for internal modifications, which extends timelines and limits some specification choices. Conservation area properties face additional planning considerations. Buildings with restricted access (basement spas, upper-floor facilities, tight urban sites) face higher logistics costs for materials delivery and waste removal.

Budget by refurbishment type

Rather than presenting a single cost-per-square-metre figure, it is more useful to think about budget in terms of what you are actually doing. Three broad categories apply to most UK spa refurbishments.

Cosmetic refresh

A cosmetic refresh addresses the guest-facing environment without touching building fabric or technical infrastructure. This typically includes repainting and redecoration, replacement flooring, new soft furnishings and loose furniture, updated lighting (replacing fittings, not rewiring), refreshed signage and branding, and new linen, robes, and operational kit.

This level of work is appropriate for spas that are operationally sound but visually dated — facilities that have aged aesthetically but whose infrastructure is still performing well. It is also the typical approach for individual room updates between larger refurbishment cycles.

Cost range: broadly in line with commercial refurbishment benchmarks of £300–£800 per square metre, with significant variation depending on material specification and the scale of the project. A 200 sqm spa receiving a quality cosmetic refresh might represent a total investment in the region of £60,000–£160,000.

Timeline: 2–6 weeks for most projects, depending on scope. Can typically be phased around trading if sections of the spa can be temporarily closed.

Partial refurbishment

A partial refurbishment targets specific zones or systems rather than the whole facility. Common examples include treatment room upgrades (new furniture, lighting, acoustic treatment, décor), reception and relaxation lounge redesign, thermal suite replacement (sauna, steam room, experience showers), or wet area works to a single pool or hydrotherapy facility.

This category is where specification choices have the greatest impact on cost. Replacing a standard sauna with a high-specification Finnish sauna with custom timber lining and a Kelo log centrepiece is a fundamentally different project to a like-for-like replacement — both fall under “sauna refurbishment” but sit at very different price points.

Indicative ranges for common partial refurbishment items:

• Sauna refurbishment or replacement: £15,000–£60,000+ depending on size, timber specification, and whether existing infrastructure can be retained
• Steam room works: £20,000–£50,000+ depending on size, tile specification, and generator replacement
• Experience shower installation: £8,000–£25,000 per unit
• Treatment room refurbishment (per room): £8,000–£25,000 depending on scope and specification
• Reception and relaxation lounge redesign: £30,000–£100,000+ depending on size, joinery complexity, and FF&E specification
• Air handling / ventilation upgrade: £40,000–£100,000+ for commercial spa environments

For a partial refurbishment targeting a specific zone (say, a thermal suite and relaxation area within a 400 sqm hotel spa) a realistic budget range is £150,000–£400,000 depending on specification and the condition of existing systems.

Timeline: 6–16 weeks on-site, plus 2–4 months of design, specification, and procurement before construction begins.

Full renovation

A full renovation involves the comprehensive redesign and rebuild of the spa. New layout, new infrastructure, new finishes throughout. This is appropriate when an existing facility is operationally compromised, when a property is repositioning to a higher market tier, or when the building has been significantly altered and the spa needs to be reconfigured to match.

Full renovations are complex projects. They typically require architects or specialist spa designers, mechanical and electrical engineers, structural engineers, and a principal contractor capable of coordinating multiple specialist subcontractors. The design phase alone (producing construction drawings, specifying equipment, navigating building regulations and any planning requirements) commonly takes four to six months before a spade goes in the ground.

Published UK project costs give useful reference points. The Grand Brighton’s full spa build as part of a wider hotel refurbishment represented a £2.5 million investment for a 699 sqm facility featuring six treatment rooms, a hydrotherapy pool, jacuzzi, and relaxation areas. [Source: Conference News, September 2025] The Vale Resort’s targeted relaxation zone refurbishment (new heated water beds, updated lounge, new spa pool collaboration) represented a £100,000 investment. [Source: Visit Wales trade media]

For full renovation of an established hotel or resort spa, a working budget range of £2,000–£4,000+ per square metre reflects the technical complexity involved — the mechanical and electrical requirements, specialist waterproofing, commercial-grade tiling, bespoke joinery, and equipment procurement that a high-quality spa environment demands. A 300 sqm spa fully renovated to luxury specification would therefore represent an investment of approximately £600,000–£1.2 million or more.

Timeline: 4–8 months on-site for a full renovation. Total project duration from initial brief to opening (including design, procurement, and construction) is typically 12–18 months.

The wet area question

Wet areas deserve their own section because they are where budgets are most frequently underestimated, where the consequences of cutting corners are most severe, and where Alkaline 360’s experience on projects across the UK is most directly relevant.

The term “wet areas” covers anything involving water. Pools of all types, hydrotherapy pools, plunge pools, vitality pools, steam rooms, experience showers, and the technical infrastructure that supports them: plant rooms, filtration systems, pipework, drainage, and the specialist waterproofing that holds it all together.

What makes wet areas costly is not primarily the visible finishes, it is the technical layers underneath. A commercial pool or thermal suite must perform to precise water quality, temperature, and safety standards. The structural support must withstand constant water exposure and thermal cycling. Waterproofing must be continuous and correctly specified for the substrate. Plant room equipment (filtration, dosing, heat exchangers) must be sized correctly for the bather load and usage patterns. Ventilation must manage humidity levels to protect the building fabric and maintain guest comfort.

When any of these technical layers are underspecified, the results manifest as operational problems (water quality failures, surface deterioration, humidity damage to adjacent spaces, recurring maintenance issues) that are expensive to correct after the fact. We have seen projects where superficially attractive costs were achieved by specifying inadequate waterproofing or underpowered plant, with consequences that emerged within two to three years of opening and required significant additional investment to resolve.

Indicative wet area investment ranges:

• Pool or hydrotherapy pool refurbishment (retiling, regrouting, equipment service): £30,000–£80,000+
• New commercial plunge pool or vitality pool: £80,000–£200,000+ depending on size, finish, and infrastructure
• New bespoke pool (custom shape, premium finish): £150,000–£500,000+
• Full pool replacement (structural works, new shell, plant, finishes): £250,000–£600,000+

The Alkaline 360 approach to wet area projects starts with a thorough assessment of existing infrastructure. What can be retained, what must be replaced, and what hidden risks exist. This informs a budget that reflects reality rather than optimism, which is ultimately what protects operators from mid-project surprises.

Wet area projects are where early expert input pays for itself. Getting the technical specification right at feasibility stage costs a fraction of correcting problems after handover. Discuss your project with our team →

What operators consistently underestimate

Across the many projects we have delivered, certain budget items catch operators off-guard with regularity. Being aware of them in advance is straightforward budget protection.

Mechanical and electrical upgrades.

Spa environments make exceptional demands on building services. High humidity levels, constant water use, precise temperature control, and extended operating hours all place spa facilities at the more intensive end of building services requirements. Older properties frequently require electrical supply upgrades, pipework replacement, and drainage modifications to support a modern spa specification. These works sit within walls and floors. They are invisible in the finished project, but they form a substantial proportion of the budget. A building services survey before design work commences is essential.

Ventilation.

Humidity management is one of the most technically demanding aspects of spa design, and one of the most commonly underspecified. Commercial spa environments require dedicated air handling units with precise humidity control, not domestic or standard commercial ventilation systems. Budget from £40,000 upwards for a commercial-scale installation, and more for larger facilities or those requiring independent zones for different thermal experiences. Getting this wrong creates condensation problems, surface deterioration, and guest comfort issues that are very difficult to resolve retrospectively.

Specialist tiling.

Wall and floor tiling in spa wet areas is not a commodity product. Anti-slip requirements, continuous waterproofing substrates, grout specification for high-humidity environments, and the labour cost of skilled tilers working in complex or curved spaces all contribute to a cost-per-square-metre that surprises operators used to standard commercial tiling rates. Budget from £140 per sqm for premium product, materials, and fitting in wet areas, and significantly more for natural stone or bespoke mosaic work.

Professional fees.

Architecture, interior design, mechanical and electrical engineering, structural engineering, project management, and building regulations submissions all carry fees. A realistic allowance is 15–20% of construction cost for complex projects. On a £500,000 refurbishment, that represents £75,000–£100,000 — a figure that is sometimes absent from early budget estimates.

Planning and regulatory compliance.

Internal alterations do not usually require planning permission, but Building Regulations approval is required for structural changes, electrical works, and plumbing modifications. Listed buildings require Listed Building Consent for internal modifications. Acoustic assessments, fire strategy reviews, and accessibility compliance may be triggered by the scope of works. These costs are typically modest in themselves. The risk is timeline, not budget, since planning and consent processes can extend a programme by months.

Contingency.

A 15–20% contingency is not pessimism, it is professional practice on any refurbishment project. Behind walls and under floors, older buildings routinely reveal water damage, asbestos (in pre-2000 buildings), redundant services, and structural issues that are not visible during pre-contract surveys. Discovering these during construction without a contingency reserve forces uncomfortable choices: scope reductions, programme delays, or un-budgeted overspend. Operators who build in proper contingency invariably report better experiences than those who do not.

Phasing your refurbishment

For many operators, a phased approach is the most commercially sensible route to a fully refurbished facility. Phasing spreads capital expenditure across time, minimises revenue loss from closures, and allows operational learning between phases.

The key to successful phasing is having a master plan before any work begins. Phasing a refurbishment without an agreed end-state design creates the risk that Phase 1 decisions constrain Phase 2 options — a particular risk with wet areas, ventilation, and drainage infrastructure that is expensive to move once installed.

A well-structured phasing approach might look like this:

Phase 1: Front-of-house and treatment rooms.

Reception, changing facilities, relaxation lounge, and a rolling programme of treatment room upgrades. These works have the least impact on operational continuity, can typically be sectionised to keep the majority of the spa trading, and deliver an immediate improvement to guest perception.

Phase 2: Thermal suite and wet area upgrades.

Sauna, steam room, experience showers, and hydrotherapy facilities. These works require closure of the relevant zones but can be scheduled during the facility’s lower-demand periods. Lead times on bespoke thermal equipment (particularly from European manufacturers) mean procurement must begin well in advance of construction.

Phase 3: Pool and major wet area works.

The most disruptive and technically complex work is typically left to the final phase, by which point the rest of the facility has been upgraded and a full closure (or extended section closure) is commercially easier to justify.

Phasing typically extends total project duration. A refurbishment that might take six months as a single project may take 18–24 months phased, but the commercial case for doing so is often strong, particularly for destination spas or hotel facilities where extended full closure is not viable.

Thinking about how to sequence your refurbishment? We work with operators at the earliest planning stages to develop phasing strategies that protect revenue while delivering transformation. Start a conversation →

What a well-executed refurbishment delivers commercially

Budgeting for a refurbishment is ultimately a question of return, not just cost. The investment needs to be understood in terms of what it unlocks commercially — and the evidence base for well-executed spa refurbishment is positive.

Pricing power.

Refurbished facilities support higher treatment prices and day spa rates. Facilities that have not been updated for a decade are frequently priced below their market position because the environment does not support premium rates. A refurbishment that restores (or elevates) the physical environment removes that constraint.

Occupancy and dwell time.

A well-designed spa environment encourages guests to stay longer, visit more frequently, and spend more on ancillary services: food and beverage, retail, additional treatments. Industry analysis consistently identifies spa guests as among the highest-spending segments within hotel properties. [Source: Victus Consultancy hospitality analysis]

RevPAR uplift.

Hotels that invest in spa and wellness facilities typically see improvements in room rate and occupancy as the spa becomes a booking motivator rather than an amenity footnote. Industry consultants cite 18–36 months as a typical payback period for compact, high-utilisation wellness amenity investments. [Source: Luxe Wellness Spaces wellness ROI analysis, 2025]

Asset value.

Spa facilities in good condition support higher property valuations and transaction prices. Conversely, deferred refurbishment accumulates as a liability that sophisticated buyers will factor into acquisition pricing.

Staff retention and recruitment.

A well-maintained, well-equipped facility is a meaningful factor in attracting and retaining skilled therapists – a persistent challenge across the UK spa industry. The quality of the working environment matters to the people who work in it.

The projects Alkaline 360 has been involved in across UK hotels, resorts, and leisure facilities consistently demonstrate that operators who approach refurbishment strategically (investing in the right areas, specifying correctly, and planning properly) achieve returns that justify the investment. The facilities that struggle commercially after refurbishment are almost always those where budget pressure led to compromises in the technical foundation: wet areas specified too lightly, ventilation inadequately sized, or infrastructure deferred that subsequently fails.

How to brief a design consultancy or contractor

The quality of the brief you bring to a design consultancy or contractor has a direct bearing on the quality of the response you receive, and therefore on your ability to make meaningful comparisons between proposals.

A strong brief for a spa refurbishment includes:

A clear statement of intent.

What is the commercial objective of the refurbishment? Are you repositioning to a higher market tier, restoring a facility that has become dated, adding new thermal experiences, or responding to specific guest feedback? The design response to each of these objectives is different.

Existing drawings and surveys.

As-built drawings, any structural surveys, M&E documentation, and building regulations certificates for previous works. The more information a design team has about the existing condition of the building, the more accurate their early cost estimates will be.

A realistic budget indication.

The most productive early conversations happen when an operator is willing to share a budget range. It allows a design partner to tell you honestly whether your objectives are achievable within that range, or whether they need to be adjusted. Withholding the budget leads to proposals that are designed without a financial anchor — and the gap between expectation and reality only emerges after significant design investment.

An honest assessment of constraints.

Operating requirements during construction, seasonal trading patterns, lease or franchise constraints, listed building status, or planning history that may be relevant. All of this is better disclosed at the outset.

A timeline.

When does the refurbishment need to be complete? Working backwards from an opening date disciplines the programme planning and procurement process, and surfaces any constraints early.

At Alkaline 360, early-stage conversations are genuinely without obligation. We regularly spend time with operators at the idea or feasibility stage, helping them test whether their vision is commercially achievable, understand what a realistic budget looks like, and identify any technical or planning considerations before they commit to a design process. That early investment of time consistently saves operators from expensive discoveries later.

Ready to put some early-stage numbers on your refurbishment? A conversation with our team costs nothing and typically clarifies the project significantly. Get in touch →