The Perfect Formula for Designing a Spa

Raison d'Etre's formula for the perfect spa // Photo credit: scyther5/iStock/Getty Images Plus

Raison d’Etre, the global spa consultancy and Think Tank for Wellness, has developed a formula for the perfect spa design. The team at Raison d’Etre believe formulas for ratios and design plans are essential when it comes to balancing spa design with operational needs, and applies this method to the unique needs of each individual project. Ian Bell, the senior project manager at Raison d’Etre, set outs the five key factors that are used in every project, all balanced by the flow of energies and pattern to detail, to ensure the integrity of the original space is maintained.

Five Key Factors ÷ Two Overarching Objectives = Perfect Spa Design

Raison d'Etre's Five Key Factors:

1. Industry KPI’s

These inform the feasibility and size of spa needed for a project based on factors such as cost, profit, market size, and resources. KPI’s tell us, for example, how many guests we can expect on a daily basis in a day, hotel or resort spa but also the ratio of treatments that are generally booked. An example is that approximately 80 per cent of guests to a spa may simply be looking for a good massage.

2. Space Requirements

Starting with the overall space that is allocated for the spa, we then work with the finer details such as size of lockers in a changing room or space needed for saunas and steam rooms to accommodate the maximum number of guests, right down to the space needed around a treatment table so that a treatment can be performed. Each comes with its own understanding and formula and all need to be integrated to create the perfect space within the parameters of the spa design.

3. Creative Use of the Edges

A spa is never a separate entity and the edges and margins of the spa are where we need to focus attention too. These are the crossing points where a guest comes from one world into the other. For example, we need to be aware how a conference room on the other side of a relaxation room wall might impact on the spa environment. So here, we integrate the spa into the whole, rather than trying to see it as separate.

4. Balance of Guest Needs and Operational Needs

Other formulas help us to create balance within the spa, such as the minimum requirement of back of house facilities that are needed for a spa to be run successfully. Another is the percentage of circulation that needs to be added around the facilities of the spa, which include the corridors. As these spaces do not directly generate income, they are often ignored or reduced but only to the detriment of the guest experience and ease of operation.

5. Timelines

Working towards the grand opening, we work with linear timelines to ensure a smooth opening of a spa. These combine all our knowledge of lead times for the ordering of custom made supplies and equipment to marketing efforts, product testing and time needed for successful recruitment. 


The most comprehensive and up-to-date information relating to the pandemic.

All the day's coronavirus-related news and additional stories for small businesses.

Raison d'Etre's Two Overarching Objectives:

1. Flow of Energy through the Spa

The journeys through a spa follow circular flows of energy. One is the guest flow from busy to still to busy again, the other is the flow of staff to support all aspects of the guest journey and spa operation. We need to manage both flows of energy and the crossing points between the two.

2. From Pattern to Detail

Foremost is keeping the overall concept and flow in mind and then moving from there into the details. This will inform anything from the kinds of products used, to where sockets, music and light panels are placed in a treatment room.

Those five formulas, balanced against the two overarching objectives, create the perfect formula for spa development.


Five Things to Remember When Opening a New Spa

The Secret Weapon for Designing a Spa

Four Steps to Launching a Successful Spa in 90 Days