Structure comes before everything
A commercial gym imposes loads most Indian commercial floors were not designed for. A rack of dumbbells to 50 kg concentrates around 1,200 kg into four square metres. A loaded barbell dropped from waist height produces a dynamic load several times its static weight. Standard commercial floor design is often 3–4 kN/m²; a free-weight zone wants 5–7.5 kN/m², and a structural engineer must confirm what the slab actually has before a lease is signed.
The related issue is vibration transmission. A dropped deadlift in a first-floor gym is felt and heard in the tenancy below, and it is one of the commonest sources of dispute in Indian mixed-use buildings. A ground-floor unit with the slab on grade removes the problem entirely; on an upper floor it needs a floating floor system with a resilient layer, which costs ₹350–₹800 per sq ft in the affected zone and must be designed rather than improvised.
| Zone | Floor loading | Floor build-up | Clear height | ₹ per sq ft |
|---|---|---|---|---|
| Free weights / deadlift platform | 5–7.5 kN/m² | 40 mm rubber over 20 mm shock pad | 3.0–3.6 m | ₹520–₹1,100 |
| Machines / resistance | 4–5 kN/m² | 15–20 mm rubber tile | 3.0 m | ₹220–₹480 |
| Cardio | 3–4 kN/m² | 12–15 mm rubber or vinyl | 2.8 m | ₹180–₹380 |
| Functional / turf | 4–5 kN/m² | Artificial turf over shock pad | 3.6 m | ₹280–₹620 |
| Studio (yoga, dance) | 3 kN/m² | Sprung timber or vinyl | 3.0 m | ₹320–₹780 |
| Changing and wet areas | 3 kN/m² | R11 tile over waterproofing | 2.7 m | ₹420–₹900 |
Rubber thickness is the specification most often cut. 20 mm in a deadlift zone will crack the screed beneath within a year.
Air: where gyms actually fail
Members leave gyms because of smell and heat far more often than because of equipment. A person exercising hard produces several times the metabolic heat and moisture of a person at a desk, and a room full of them needs an air change rate closer to a commercial kitchen's than to an office's. Six to ten air changes per hour is the working range, with fresh air rather than recirculation, and dedicated extraction in the changing rooms and toilets.
- Fresh-air ventilation, not just cooling. A room full of split ACs recirculates carbon dioxide and odour; members notice within twenty minutes.
- Separate extraction in changing rooms and toilets, running continuously, at 10–15 air changes per hour.
- Ceiling fans in addition to air conditioning. Air movement across the skin matters more than air temperature for someone exercising.
- Target 22–24 °C and 50–60% RH on the gym floor. Mumbai's ambient humidity makes the second number the harder one.
- Position the cardio zone near the fresh-air supply, because that is where the heat and moisture load is highest.
- Plan for the smell of rubber flooring. New rubber off-gasses for several weeks; ventilate hard before opening rather than apologising for it afterwards.
Layout and sightlines
- Put cardio where members are seen and free weights where they are not. New members are self-conscious; the free-weight zone should not be the first thing visible from reception.
- Keep a clear circulation spine of 1,500 mm through the floor. Every gym that grows fills its circulation with equipment and becomes unusable at peak.
- Allow 1,200 mm behind machines for a person to pass while another is working, and 2,100 mm around a squat rack.
- Mirrors on the free-weight and studio walls only. A mirrored cardio wall means members watch themselves for forty minutes, which most dislike.
- One staff sightline across the whole floor, from the reception or the trainer's position. Supervision is a safety requirement, not just a service one.
- Water and towels at two points, not one. A single station at reception generates a queue across the circulation spine.
Costing a 3,000 sq ft gym
| Element | Cost | Notes |
|---|---|---|
| Civil, partitions, changing rooms | ₹9–₹18 lakh | Wet areas drive this |
| Flooring, zoned | ₹7–₹16 lakh | The largest single finishes line |
| HVAC and ventilation | ₹9–₹20 lakh | Fresh-air handling, not just cooling |
| Electrical and lighting | ₹5–₹11 lakh | Cardio equipment is a real load |
| Plumbing, showers, hot water | ₹5–₹12 lakh | Showers are a lease-selection issue |
| Mirrors, joinery, lockers | ₹4–₹9 lakh | Lockers are ₹3,500–₹9,000 each |
| Acoustics and vibration control | ₹2–₹7 lakh | Mandatory on an upper floor |
| Reception, signage, branding | ₹1–₹4 lakh | — |
| Total, excluding equipment | ₹42–₹95 lakh | ₹1,400–₹3,200 per sq ft |
Equipment for a 3,000 sq ft gym typically adds ₹45 lakh to ₹1.6 crore depending on brand and whether cardio is imported.
Confirm the slab loading and the duct route before you sign. Those two facts decide whether the gym is possible at all.
Greenbox commercial fit-out lead
Changing rooms, showers and where members judge you
Members forgive dated equipment and do not forgive a poor changing room. It is also the most expensive part of a gym per square foot, because it is a wet area with plumbing, ventilation, hot water and lockers in a small footprint. The provision that works is roughly one shower per 25–30 peak concurrent members, one WC per 30, and lockers at 1.2 times peak concurrent membership, because members leave belongings during a session and some leave them all day.
Three details separate a good changing room from a bad one. A genuinely dry changing zone, physically separated from the shower zone by a drained transition, so people are not dressing on a wet floor. Somewhere to sit while putting on shoes — a 400 mm bench per four lockers, which is constantly omitted. And continuous extraction at 10–15 air changes per hour, because a changing room without it smells within a month of opening and never recovers.
| Item | Provision | Note |
|---|---|---|
| Showers | 1 per 25–30 peak concurrent members | R11 floor, thermostatic mixer |
| WCs | 1 per 30 peak concurrent members | Separate from the shower zone |
| Lockers | 1.2 x peak concurrent members | ₹3,500–₹9,000 each |
| Bench seating | 400 mm per 4 lockers | The most-omitted item |
| Extraction | 10–15 air changes per hour | Continuous, not switched |
| Hot water | 40–60 litres per shower per peak hour | Size the system to peak, not average |
Two more items belong in the budget from the start rather than appearing as variations. The first is the sound system and the acoustics around it: a gym plays music at 75–85 dBA, and in a hard-surfaced room that becomes an indistinct roar rather than music, while also transmitting to neighbouring tenancies through the structure. Distributed ceiling speakers with an absorptive ceiling cost more than two wall-mounted boxes and are the difference between a floor people enjoy training on and one they leave early. The second is a written vibration and noise agreement with the landlord and the neighbours, obtained before the lease is signed rather than after the first complaint.
Amenity and fitness spaces planned around loading and air
Selected work by Greenbox Design Studio. Tap any image to enlarge.
Frequently asked questions
What floor loading does a gym need?+
5–7.5 kN/m² in free-weight areas, against the 3–4 kN/m² that many Indian commercial floors are designed for. Get a structural engineer to confirm the actual slab capacity in writing before signing a lease — it is the single fact that determines whether the space can be a gym at all.
How thick should gym rubber flooring be?+
40 mm over a 20 mm shock pad in any zone where weights are dropped, 15–20 mm under machines, and 12–15 mm in cardio areas. Twenty millimetres in a deadlift zone transmits impact straight into the screed and cracks it within a year, which is the commonest specification failure we see.
How much ventilation does a gym need?+
Six to ten air changes per hour of fresh air on the gym floor, and 10–15 in changing rooms and toilets with continuous extraction. Air conditioning alone recirculates and does not address carbon dioxide or odour, which is why gyms with adequate cooling and inadequate ventilation still feel unpleasant.
What ceiling height does a gym need?+
3.0 m clear as a minimum, and 3.6 m where anything is pressed overhead, where a functional rig is installed, or where boxing bags are hung. Cardio areas can work at 2.8 m. Measure clear height below ducts and sprinklers, not slab to slab.
Can a gym be on an upper floor?+
Yes, with a verified slab capacity and a floating floor system with a resilient layer in the free-weight zone, costing ₹350–₹800 per sq ft there. Without it, dropped weights transmit impact and noise to the tenancy below, which is the most common cause of dispute for upper-floor gyms in Indian buildings.
What does a gym fit-out cost?+
₹1,400–₹3,200 per sq ft ex-GST excluding equipment, so ₹42–₹95 lakh for a 3,000 sq ft studio at 2026 metro rates. Equipment adds ₹45 lakh to ₹1.6 crore depending on the brand mix and how much of the cardio range is imported.