Which is the right sink for your project?

Our new series looking at the nitty gritty of technical details starts with an assessment of one thorny aspect of washrooms

JRA’s 120 Holborn, a mixed use development for client Zebulon.  An industrial aesthetic was chosen for washrooms, appealing to a media led tenant.
JRA’s 120 Holborn, a mixed use development for client Zebulon. An industrial aesthetic was chosen for washrooms, appealing to a media led tenant.

THE ARCHITECT
Andy Hill, director, John Robertson Architects

Because of the way plumbing works the convention is for linear arrangements of loos and sinks, around the stair and service cores. Wash basins are usually ‘floating’ elements in washrooms. Colours and materials do change with fashion but generally for commercial spaces we use a restrained palette of materials with mirrored panels at the end creating an illusory ‘vanishing effect’. 

When fitting out toilets in commercial spaces you have to make sure the procurement is right and you’ve nailed the detailing down – with something like a ‘contractor designed portion’. In the past installers would install to design intent; but that’s rare now. Fixing sink installations back to a concrete core is always better than a studwork frame.

Clients like bowl sinks within a countertop as they provide useful space between each basin – underhung, concealed basins are the most popular. Enamel basins chip but can be repaired whereas porcelain basins can be damaged with hairline cracks, requiring replacement. Pedestal basins and troughs are less popular because they need more space and a handbag shelf behind the unit where the taps spring off. Pedestal basins are specified in some higher-end, low traffic developments but are expensive and big on statement.

Always allow enough space for operatives to easily access pipes and valves below the sinks – considering how panels are designed and removed is important – especially in super loos where services need good co-ordination and the sink will usually be tucked in tight under the dryer. 

We generally cantilever sinks off walls – they look especially good with glass backsplashes and the plumbing running behind them and sinks secured with steel straps underneath. In some offices we’ve specified long, shallow troughs but with low falls, they can drain slowly. We find troughs more popular with Square Mile banking institutions or West End offices than your average institution, who tend to be more conservative; but they certainly make for a more funky feel to washrooms.

Sinks on countertop.
Sinks on countertop. Credit: Anke Salomon

Sinks on countertop

Potentially large amounts of redundant stone or worktop out of site under basin.

Gives a hotel feel to a commercial washroom but check space plan efficiency.

Long, linear wash handbasin may be slow to drain.

Handbag and make-up space limited.

Long runs of sealant to rear of basin and sides to be avoided/reduced.

Mix of trades required or turnkey contract with specialist contractor.

Stand-alone pedestal sinks.
Stand-alone pedestal sinks.

Stand-alone pedestal sinks

Not common for commercial washrooms. Very fashionable but will go out of style. Good for boutique hotels or high-end restaurants for lower traffic WC facilities.

Less space efficient – check space requirements in the washroom.

Likelihood of a greater cleaning regime, especially to front and rear of pedestal.

Plumbing connections to underside or rear to be considered. Greater emphasis on install quality of visible chrome plumbing.

No handbag or makeup space.

Sink underhung on counter top.
Sink underhung on counter top.

Sink underhung on counter top

Most common form in commercial offices. Brings ‘hotel’ feel to washroom. Also allows for tighter space plan.

Detail between basin rim and stone surround needs to be co-ordinated.

Stone top requires increased support.

Less splash to floors.

Dark stone surrounds often stain with hard water marks. Cleaning regime important.

Selection of stone and veining important to suit shape and style.

Requires multiple trades or turnkey specialist contract.

Cantilever taps to be secure and no wobble. 

 

Trough-type sink.
Trough-type sink.

Trough-type sink

The increased size, length and weight will require more co-ordination with adjoining supporting elements.

Tap height is important to avoid splashing and a continuous splashback will be needed.

The detail of the tap protruding through the wall may need a cover plate or surround.

Long troughs may take longer to drain.

The ability to replace damaged elements of the trough are limited and reduce flexibility.

No space for a handbag shelf or towels so a handryer may be necessary.

Plumbing  beneath is likely to be visible so will need to be well executed in quality chrome finish. 


 

THE INSTALLER
Gordon Emms director, Brown & Carroll

We’ve fitted out washrooms with every conceivable arrangement of sinks and for us it’s all about service integration and access. Generally, we handle stone or Corian undermounted sinks but troughs are gaining popularity. Stand alone sinks are more common in high-end restaurants than offices.

Joiners do the procurement usually – we get a schedule from the architect but these tend to lack the ironmongery. A well-considered specification is good to avoid variations – design intent drawings simply don’t cut the mustard if you want to keep a handle on install costs. 

Many contemporary washrooms have cantilevered sink runs, which need a steel support structure. This is best installed before wall screeding so must be co-ordinated during design by the architect. Preparatory work must be done so you can close the wall up before installing the sink, which means pipework needs to be in exactly the right position. 

Unisex loos are leading to more self-contained cubicles with loo, washbasin, feature mirror and dryer. But these tend to be very tight spaces and need good services co-ordination. On a base build scheme, to deal with higher office densities we might map out possibilities for extending loos. 

We do see impractical detailing – butting countertops directly into walls for example. Better to face a wall in the same material. It might be more work but it avoids the wall/ countertop junction and looks seamless. 

THE FACILITIES MANAGER 
Jake Castree property manager, British Land

I’ve been working in building management for the last 20 years and over that time the main issue with washrooms has been access. It’s getting at the plumbing and access for the replenishment of liquid soap reservoirs when they are below the sink. It’s important to consider the operatives who have to get to pipework as part of regular building maintenance; as for cleaners, they’ll always prefer wall mounted soap dispensers. 

Across our estate we mostly have long worktops with undermounted basins – we get the best tenant feedback for them and they are the easiest to maintain from a facilities point of view. We find it’s better to specify the best materials you can. Good polished marbles and granites are easy to keep clean without resort to specialist products – unlike cheaper surfaces that can hold the dirt and so need them. We shy away from the specialist cleaner that can sometimes appear as part of a building’s O&M Manual. We prefer just to wash with water. Don’t specify patterns on countertops and matt black surfaces show up fingerprints.

A persistent problem is the location of hand dryers relative to the sinks – usually when they are installed at a later date. Minimising the distance between them ensures that floors don’t get wet – with the possible hazards that might present.

Latest

Dessau’s Torten Estate featured in an influential lecture and exhibition concentrating on the housing crisis, given by Walter Gropius just before left the UK for America

Solving the housing problem was top of Walter Gropius’ concerns

In the run-up to the election Andrew Forth, RIBA’s head of policy and public affairs, explains how the RIBA’s manifesto lobbies politicians to create a built environment that is ‘safer, better and more sustainable’

Head of policy and public affairs at the RIBA, Andrew Forth, on the key points

The architect’s vision for Lower Giles Farm house near Bolton got diluted by the client's self-build, but the dilemmas resonate with many

Manchester meets moorland at cantilevered Paragraph 55 home near Bolton

There’s no doubt that Banister Fletcher’s tome is all the better for its heavy revision, but the reduced role of its drawings hurts

Welcome repositioning is at cost of drawings

Lessans House by McGonigle McGrath Architects shows you don’t need a big budget to achieve excellence

You don’t need a big budget to achieve excellence