Sustainable Bathroom Design

Sustainable Bathrooms

In the past, bathroom designs have been a prestigious show of wealth with sleek contemporary designs and stark aesthetics. Coming into an age where sustainability and trend collide, water saving features and reducing your environmental impact are paramount. Over recent in years, local authorities have taken steps to raise awareness of how precious water conservation is.

Intelligent bathroom remodelling; before you de-install the bathroom, knock through walls and skip the contents, stop and think. Question your motives, needs and desires. ‘I want an eco bathroom’ does not necessarily equate to buying everything new and throwing away everything old. Construction waste will be landfilled and could defeat your environmental intent. Be mindful of what you throw away and re-use as many of the existing fixtures and fittings as possible, whilst bringing in key water saving features like a new WC or shower system. By exploring all possibilities you are able to make an informed decision.

The key to sustainable bathroom design is to achieve the maximum aesthetic, functional and practical enhancement with the minimum amount of materials, resources, energy, hazards to your health.

Green Bathroom Modelling Guide

  • Planning to reduce, reuse and recycle
  • Reuse construction waste
  • Recycle any site waste
  • Repair, restore and reuse existing fixtures and fittings
  • Floor, wall and roof insulation (non-toxic, formaldehyde and fibreglass free)
  • Double or treble glazing
  • Mechanical ventilation
  • Sealing of all ductwork
  • Passive & natural ventilation
  • Low energy lighting system
  • Make use of natural daylight
  • Bathrooms with windows that open
  • Flow regulator and aerated shower heads and taps
  • Grey water, low and dual flush WCs
  • Insulated plumbing and pipework
  • Low or zero VOC materials (flooring, paint, textiles)
  • Renewable and sustainable resources
  • Recycled content products
  • Salvage, reclaim and second hand sanitary ware and materials
  • No PVC, vinyl or acrylic
  • Solvent free adhesives

Universal Bathroom Design

Universal design is to design with every occupant in mind, allowing free use of the bathroom no matter of age or physical mobility. This type of design method creates a bathroom that is safe, user-friendly, efficient, comfortable, appropriate and adaptable for all. Some of the universal bathroom design principles are:

  • Bathroom doors hinged to swing outwards with a wider opening to allow all users access.
  • Bath, WC, bidet and shower grab rails to assist users with restricted mobility.
  • Raised height WC pans that are fitted with no-slam toilet seats suited to all users except very small children.
  • Hand basins that are mounted to the wall to provide leg room for wheelchair or users who need to sit whilst washing.
  • Handles and taps to be specified as lever-style suited to people with reduced hand mobility.
  • Shower cubicles that do not have a threshold, readily accessible by wheelchair users, suited to wet room designs and shower trays that are situated slightly lower than floor level.
  • Showers that can be hand held and are not fixed to the wall, suited to occupants who use whilst seated.
  • Showers that have a built in flip up seat, bench or triangle seat for the corner of a cubicle.
  • Shower system that provides an auto stop button or button that reduces the flow to a trickle to save reaching the control whilst washing hair/body.
  • Wheelchair access within the bathroom to allow for a full 180 degree turn, including the door swing.

Bathroom Design

Bathroom Considerations

Repair, refurbish, renovate and make new. From restoring flooring to resurfacing baths, renovating a bathroom keeps the existing fittings and mechanical systems in place. Using what the occupant already has, repairing or replacing and sprucing up with a new paint job and colour scheme. This is a good way of reinventing your bathroom without incurring the environmental costs of remodelling.

To re-design the bathroom layout including re-positioning of the bathroom sanitary ware and fixtures as well as re-work of the plumbing and mechanical systems (hot & cold feed, waste pipe, vent, soil pipe, heating system, lighting, mechanical ventilation). This is the most invasive environmentally as it may create a lot of construction waste and use virgin materials and resources for fixtures and fittings.

Bathroom Layouts

One Wall
All plumbing facilities (Bath, shower, WC, basin, bidet) are located along a single wall. Suited to single or dual occupancy due to probable restricted size. Also suited to en-suites, guest bathrooms and bathrooms with room only for half bathtubs.

Two Walls
Plumbing facilities split between two walls. Bath and/or shower located on one wall, WC, bidet and basin located on the other. Bath or shower may sit in the 90 degree angle of the two walls. Typical bathroom layout for small to medium sized homes.

Three Walls
Plumbing facilities located on three walls. The bath and/or shower are located on one wall, the WC and bidet on one wall and the basin or dual basins on the other wall. Suited to the master bathroom of a home and multiple users e.g. mother and children or husband and wife. This type of layout is the easiest to remodel, as the plumbing services are located on all three walls already. In larger bathrooms, it is easier to bring in functional items like washing baskets, and towel dryers.

Bathroom Users

Bathroom design is usually left to the end, with other areas in the home taking priority you could be left with a very small space to make efficient use of. Plus the added disadvantage that once the bathroom has been fitted out; it’s not easily changeable like other rooms.

In the initial planning stages consider each individual. Whether an adult, teenager, baby, child, elderly or wheelchair user, each has their own needs. In a family home it may not be possible to please everyone in terms of capabilities and access. The key is in designing a bathroom that is flexible for all users, following the principles of ‘whole building design’.

In a bathroom every member of the home should be able to use each of the facilities without obstruction, knocking elbows, knees, arms or heads. Enough space should be allowed to move around, to open the bathroom units, entrance or shower door and to get in and out of the bath freely. This includes single use, dual use and when cleaning. Storage is often overlooked and can be crucial to the user-friendliness of the design.

The amount of privacy varies between occupants. With an external window, the considerations are what the window faces onto, whether a wall, secluded back garden or overlooked by a street or another home. Window shape, size and location can aid privacy, with narrow long windows being positioned high up on a wall to allow light in, whilst providing privacy. Audio privacy is another consideration, with adequate sound insulation.


  • Occupants Age, physical ability, preference, tasks, function, aesthetic, comfort
  • Function Additional use e.g. washing machine, household storage, dressing area
  • Design Height and location of furniture and sanitary ware for users; children, reaching, stooping etc.
  • Privacy Windows, locks, audio insulation, location of WC in relation to doorway, half height partitions for added privacy
  • Openings Doors, windows, may open without obstruction of fittings or user, occupant not visible from exterior
  • Space Flow, awkward angles, crowding
  • Number Number of users at any one time, design to be practical

Bathroom Lighting

Maximise natural daylight with unobtrusive window dressings, allowing the bathroom to flood with light. Consider window location when situating the bath, as some users may not be able to access the opening by reaching over the bath or bathroom units to open. Consider window privacy, using opaque glass or window film. If a window dressing is a must, go for roller blinds that roll from the bottom up, allowing light in from the top.

Where artificial light is needed, choose energy efficient light bulbs such as LEDs or CFLs suited to a bathroom setting. The aim is to save energy and money. Design lighting according to the users to include task and ambient fittings for a number of activities; putting on makeup, plucking eyebrows, shaving, reading, relaxing in the bath etc. The level and height of task lighting depends on the activity with the brightest when using mirrors, vanity lights are intense, yet take care with glare. Wheelchair users may require lower level vanity lighting. Accessibility of light switches should be considered for each user, where most convenient.

In accordance with building regulations, bathroom lighting must be located in zones according to moisture exposure. All electrical work in a bathroom must be carried out by a qualified electrician and in accordance with wiring regulations from the Institute of Electrical Engineers (IEE) and current building regulations. It is not permitted to bring portable lighting into a bathroom, all must be architectural.

Zone 0 Bathroom Lighting
The area within the bath or shower where water is held. Electrical products max 12V. AC or 30v ripple-free DC is permitted outside of zone 3+. Minimum IP rating of IPx7.

Zone 1 Bathroom Lighting
The area above the bath and shower in zone 0, up to a height of 2.25m. Electrical products maximum 12V with the transformer located in zone 3+. Minimum IP rating of IPx4.

Zone 2 Bathroom Lighting
The area outside of zone 0 and 1, up to a height of 2.25m vertically and up to a width of 0.6m horizontally. Including the window reveal when the window sill is by the bath. Electrical products maximum 12V with the transformer located in zone 3+. Minimum IP rating of IPx4. Hand basins are classed as zone 2.

Zone 3 Bathroom Lighting
Any area outside of zones 0, 1 and 2. This used to be separated and classed as zone 3, however now any light fitting can be fitted here. No minimum IP rating. Check if the light fitting advises ‘not for use in a bathroom’. Portable electrical equipment is not permitted other than maximum 12V or shaver.

IP Ratings
An IP rating is a classification system for sealing on electrical equipment in regards to suitability against intrusion from moisture and foreign bodies (fingers, tools and dust). IP means ‘Ingress Protection’ and the digits after this acronym advise the class of protection e.g. IP65. Where a single digit is used, an ‘X’ fills the space e.g. IPX4.

Solar Tubes
Bathrooms without windows can be dark. In homes where the bathroom is located beneath the roof, consider solar tubes / tubular skylights. These provide bright daylight through a lens and diffuser tube that fits between the ceiling and roof. Typical to a standard ceiling light in appearance without the cost of artificial light, nor the heat loss of traditional skylights. Additional artificial lighting is needed for gloomy days and night-times. Available for pitched or flat roofs.

Sustainable Bathroom


Water saving is the priority, with conventional baths using between 150 – 250 litres of water up to the overflow height. Ideally remove the bath and replace with a water saving shower. For those who like bathing, install a shower to give you the choice and convenience of both. Avoid buying baths that are larger than normal e.g. luxury size or whirlpool and stick to standard or reduced sizes. Spa baths can use up to 250 to 350 litres of water to the overflow height, that kind of water usage is inexcusable.

Baths made from plastic e.g. polycarbonate, acrylic, composite etc. Plastic is a petroleum based product, when processed is energy intensive and is not biodegradable. Plastic offgasses toxic vapours into the air over the lifetime and can be difficult to recycle. If buying reconstituted natural stone or recycled content baths, investigate the type of resins used with the manufacturer, ask for the MSDS document. Plastic can flex when sitting in the bath leading to an unsteady feeling. When getting into a plastic bath it will feel room temperature. Plastic is lightweight, does not retain heat and may absorb any dyes e.g. hair colouring. This type of bath can be easily broken, cracked and scratched. Resurfacing is possible, however the result can be unsatisfactory due to a lesser end result and high costs.

Water Saving Bath
Water saving baths currently in the market do offer great water saving features, however they are made with petroleum based materials.

Traditional Baths
Most cast iron bathtubs are large using as much as 200 litres to fill to the overflow. When getting into the bath, they can feel cold. The iron can retain heat if hot enough, if the water is not hot enough then around 30% of the water heat will be used to keep the iron warm. Porcelain enamel is easy to keep clean and has good stain resistant properties. Cast iron baths made from new (virgin) materials use a huge amount of non-renewable resources and energy for material processing, manufacture and are heavy to transport. Generally this type of bath can last a whole lifetime if cared for. Cast iron is highly durable, although porcelain enamel may chip if something heavy dropped onto it. Can be repaired, resurfaced and recycled.

Second Hand
For a less expensive option to the traditional cast iron baths, consider reclaim from salvage yards or from restorers. Bring them back to life with professional or DIY resurfacing.

Sanitary Ware Renovating
Repairing, re-enamelling, resurfacing or re-polishing a bath uses less resources than buying new and diverts a product away from landfill. Whether the bath has just lost its shine, become stained, chipped or scratched, it can be given some attention and returned to a former glory. This method can also be used for hand basins, shower trays, tiles and some wall finishes.

Bathroom Basin
Avoid plastic basins, opting for natural materials or second hand. Recycled content basins are another good alternative to plastic as these reduce pressure on landfill. Stone basins are natural, non-toxic and durable although the material extraction process and transportation of these heavy items (if not sourced locally) can be energy intensive. Stone is a non-renewable resource, although some types of stone may be in abundance. Copper, bronze and aluminium basins develop a beauty of their own over time, or can be highly polished.

Sustainable Bathrooms


Hand basins use around 10% of household water. A single tap has a flow rate of around 8 to10 litres of water per minute. Imagine how water is used by taps in the home, if left on when brushing teeth, shaving, washing up, cleaning or leaking drip by drip.

Check for water leaks as this can creates a vast amount of wasted water, as much as 75 litres per day, leading to environmental damage through mindlessness. Where needed, replace washers and any faulty fittings as soon as a drip or leak happens. In the UK where water is metered, any leaking taps are adding to your utility bills.

Typical tap materials are a variety of metals; steel, iron, aluminium, chrome, bronze, brass and copper which are all known for their durable qualities. Some manufacturers offer recycled content taps. Other materials used for handles are ceramic and glass which have eco friendly characteristics although they are less durable than metal fittings.

Sustainable Showers


The shower is seen as more water efficient than a bath, however 5 minutes in a power shower can use the same amount of water as a full bath. Water consumption of a conventional showerhead is 12 – 20 litres per minute flow rate. For optimum water efficiency in the bathroom, ensure your shower uses below 10 litres per minute flow rate. In general avoid multiple nozzle showers and spa showers.


Old WC Cisterns
Your WCs could be using between 30 and 40% of water consumption in the home. This used to be tackled by putting a brick or plastic bottle filled with water in the cistern to reduce the flush volume. The consequence of this means lower efficiency of the flush and the likelihood that a second flush was needed. There are also hygiene considerations for reducing the flush volume in older WCs. Typically the older the toilet cistern, the more water it uses per flush.

Second Han Pan
WCs are usually made from ceramic or porcelain, both durable and hygienic although they are heavy in weight and are energy intensive in production. Porcelain can be recycled post consumer use into a lesser value product e.g. road base. Salvage yards will stock a variety of WC pans spanning different time periods, some antique and some modern. Many recycling networks and classified adverts will have unwanted second hand sanitary ware available.

WC seats
The most typical WC seats are made from vinyl and plastic materials which are not easy to recycle and rely on chemical processing during manufacture. These are lightweight and hygienic. FSC timber, bamboo or rubber wood WC seats are renewable choices, however over time the finish becomes worn causing cracks, making them more difficult to clean and less hygienic.

Low Flush, Dual Flush, Flush Conversion Systems
Modern low-flush WCs are water efficient as the cisterns do not hold as much water as older models, so the amount flushed is a lot less. Volume per flush either 3 or 6 litres.  Dual flush WCs use a cistern that is capable of flushing 2 different volumes of water, saving water on the lighter flushes. Dual flush WCs vary between dual buttons and single levels. When using the light flush for the majority of flushes, this can reduce water usage by up to 50%. Alternatively, a retrofit kit, fixing to the top of existing plastic WC siphons and connects to the front mounted flush handle. A siphon stops flushing when air enters the siphon, with water savings of 30 litres per person per day. Has the potential of reducing bills by 20-40%.

WC Water

Flushing water is usually fresh water either from the water tank or in some cases direct from the mains. Collected rainwater can be fed into the WC tank or alternatively a hybrid basin and WC can be designed using grey water from piped into the WC tank. Rainwater harvested from roofs can also be piped into the WC tank, although an additional plumbing supply is needed when rainfall is not sufficient.

Leaking WCs can be checked by adding food colouring into the cistern, wait for 30 minutes or so and notice if there are any streaks of colour within the WC pan, alternatively use paper towel around the inside of the WC pan, if this becomes wet between flushes this shows a leaking cistern.

Grey water is waste water from a bath, shower or basin that can be used in the home or garden where water drinking quality is not required. Kitchen sinks and washing machines are not classed as grey water due to the lesser quality of water (known as black water and only treatable with a sewage system). Greywater recycling is the term used when greywater is treated and reused whereas greywater reuse is the term used when greywater is left untreated and used. When treated greywater can be used in washing machines, WC cisterns and exterior taps.

Bathroom Furnishings

Shower doors
Opt for glass shower doors, enclosures and panels that have a ‘frameless’ design to reduce the amount of metal or plastic framing needed. These are durable, easy to clean and will not offgas into your home.

Down with PVC
The PVC shower curtain is made from vinyl, one of the most poisonous plastics produced, offgassing toxic chemicals into the air over the whole lifespan. Vinyl production is energy intensive, creates a large amount of chemical and water waste. At the end of lifespan, vinyl does not degrade and cannot be recycled easily. It lays in landfill leaching toxins into the ground and water ways. As a healthier and more environmentally friendly alternative look for PVC free shower curtains such as PEVA (non-chlorinated lightweight plastic). Or opt for 100% natural materials such as hemp or cotton. Be aware that natural materials are biodegradable and are not water resistant, they need to be aired to maintain durability so as not to harbour mould or mildew.

Bathroom Furniture
When looking for bathroom cupboards, vanity units, bath panels and shelving, eco friendly choices are; certified sustainable timber, bamboo, rubber wood, formaldehyde free MDF. Engineered bamboo holds excellent moisture and humidity qualities. Check the finishes and sealants are both suitable for bathrooms/wet environments and are eco friendly e.g. water based, natural ingredients like plant oil or do not contain chemical additives.

Soft Furnishings
Look for towels and bath robes made from 100% natural materials such as bamboo, hemp, certified organic cotton etc. Look for products that have been dyed with vegetable/plant colourings, are unbleached and without chemical additives. Eco choices for bath mats are cork, certified organic cotton and certified sustainable timber. For wash cloths, back scrubs and scrub gloves hemp is an ideal fibre which is 100% natural and renewable.

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Plastics in the Home

Sustainable Interior Design

Wood Element Colours

Feng Shui for Bathrooms