Glass partitions in London, made and fitted by one team

What you are actually paying for in a quote for glass partitions in London

Almost every price for glass partitions in London is built on a rate per linear metre, and that single number hides most of what matters. Two companies can quote the same twelve metre run and be thousands of pounds apart, not because one is greedy, but because one of them has read the drawing and the building properly and the other has priced a straight line. Before you compare prices, compare what each quote has actually allowed for.

The glass itself is rarely the biggest variable. A 10mm or 12mm toughened pane is close to a commodity and every serious supplier pays a similar sheet price. What moves the total is everything around the glass.

• Pane size. Glass gets disproportionately more expensive as sheets get taller, and past roughly three metres you are into lifting equipment, extra bodies and sometimes a glass manipulator. Dropping a design from 3.2m to 2.9m can save more than people expect.
• The head detail. A partition that lands neatly on a suspended ceiling grid is a quick install. One that passes through the grid and seals to the structural soffit above means cutting the ceiling, re-hanging tiles and making good, which is joinery and decorating work sitting inside a glazing quote.
• Doors. A frameless door on patch fittings with a floor spring costs several times a framed leaf on butt hinges, and it usually needs a recess cut into the floor. Door count is often the real difference between two quotes.
• Glass finish. Clear toughened is the baseline. Low iron, acid-etched, back-painted, laminated acoustic interlayers and integral blind units each step the price up and lengthen the lead time, sometimes by four to six weeks.
• Access and hours. Glazing an empty shell on a Tuesday morning and glazing an occupied, managed building from 7pm on a Friday are different labour rates for identical work.
• Making good. Somebody has to patch the carpet, the ceiling tiles and the plasterboard where the old layout was. If the quote does not mention it, it is not in there.

If one quote comes in far below the others, read the exclusions before you celebrate. The usual gaps are making good, ceiling alterations, acoustic sealing in the voids, manifestation, out-of-hours working and the landlord’s licence to alter. Any one of those can turn the cheapest quote on the table into the most expensive job you have ever bought.

Three questions that separate a good quote from a bad one

• What exactly is the head and base detail? Ask for a section drawing rather than a sentence. A drawing tells you whether anyone has actually looked at your ceiling and your floor.
• What is the glass specification, pane by pane? Thickness, toughened or laminated, interlayer where there is one, and the finish. “Toughened safety glass” on its own is not a specification, it is a reassurance.
• Who is doing the work? Ask whether the installers are employed or subcontracted, and ask who you telephone if a pane turns up with a chipped edge on the morning of the install.

Where glazed partitions sit in a fit-out programme

Glass goes in late. A normal office fit-out runs strip out, first-fix mechanical and electrical, partitions and doors, ceilings, second fix, flooring, decoration, then furniture. Glazed partitions are generally installed once the ceiling grid and the floor finish are down, because those two surfaces set the real dimensions and a toughened pane cannot be trimmed on site to suit a surprise.

That creates a squeeze in the middle of every programme. The survey has to happen before the glass is ordered, but the glass cannot be ordered until the surfaces it meets are final. In practice we survey after the floor and ceiling are in, which leaves a gap of a couple of weeks or more while panes are cut, polished, notched and toughened. Programmes that do not allow for that gap are the most common reason an otherwise well-run fit-out hands over late.

If the programme is genuinely tight there are two honest ways to pull it in. Use a framed aluminium system, where the frames absorb tolerance and panes can be ordered off drawings earlier with far less risk. Or split the package: survey and order the long straight runs early and leave the door openings and the awkward returns for a second survey a week later.

Will glass partition walls actually make the office quieter?

This is where expectations and physics tend to part company. A single 10mm or 12mm pane is a thin, stiff, light wall. Laboratory figures for that build-up usually land in the low to mid thirties in dB Rw. A double glazed partition using laminated acoustic panes can be tested into the low forties. Both of those are laboratory numbers, measured on a perfectly sealed sample in a test rig, and what you get in your office will be lower.

Two things eat the difference. The first is sealing. A continuous gap of a few millimetres at a head, a base or a wall junction will throw away a large slice of the rated performance, because sound follows air. The second is flanking transmission, where sound travels around the partition instead of through it: along the floor void, through a shared ceiling void, down a continuous window mullion, or through a ventilation duct that serves both rooms. Flanking is why a screen rated in the forties can still let you hear one side of a phone call.

It also helps to know what dB differences feel like to a person. A 3 dB change sits close to the threshold most people notice at all. Roughly 10 dB reads as about half the loudness. So moving from single glazing to a double glazed acoustic specification is a real, audible improvement and worth paying for in a boardroom, an HR office or a clinical room. Paying for it in a meeting room that opens onto open plan through a shared ceiling void is usually money burned.

If the brief is genuinely confidential conversations, the honest answer is often not glass. A plasterboard wall with two boards each side, mineral wool in the cavity and a proper seal up to the slab will beat almost any glazed partition for a fraction of the money. Glass buys you daylight, supervision and sightlines. Buy it for those.

Privacy: film, manifestation or integral blinds

These three get confused in almost every enquiry. Manifestation is the safety marking that stops people walking into a large pane. Decorative film is applied to the glass surface for privacy or branding. Integral blinds are slatted blinds sealed inside a double glazed unit and operated magnetically or by a motor.

• Applied film is the cheapest and the most flexible. It can be cut to any pattern, changed when your branding changes, and if it sits at the right heights with enough contrast it doubles as your manifestation. On a sunny elevation it can lift or discolour at the edges after a few years.
• Acid-etched or sandblasted glass is permanent, will never peel and looks considerably better close up. It cannot be altered without replacing the pane, and fingerprints and hand grease show badly on etched surfaces beside a door handle.
• Integral blinds give full privacy on demand with nothing to dust and nothing hanging in the room. They only exist inside a double glazed unit, so they roughly double the thickness and weight of the screen, they add cost and lead time, and if a mechanism fails you are replacing a sealed unit rather than a blind.

Choose by how often you need the privacy, not by how the showroom looked. Permanent screening to a toilet corridor, a server room or a first-aid room should be etched glass. A boardroom that needs to go opaque twice a week wants integral blinds. A general floor that just needs sightlines broken up wants film, and film lets you put your branding on the glass in the same visit.

What happens to the partitions at the end of the lease

Most London office leases carry a reinstatement clause. At the end of the term you hand the space back in the condition the lease describes, which is usually a Cat A shell with ceilings, lighting and a clear floor plate. Anything you installed comes out at your cost, and if you do not do it the landlord’s surveyor prices the work and bills you for it.

That is a good reason to care how the screens are fixed. A demountable system, framed or frameless, that bolts to track at head and base can be taken down in a day or two, with the fixings filled and the ceiling and carpet patched. A partition that has been bonded in, chased into plasterboard or had the ceiling grid rebuilt around it becomes a demolition job with a skip.

Keep the setting-out drawings, the glass schedule and the O&M file somewhere you will find them in five years. When dilapidations negotiations start, being able to show exactly what was installed and that it is removable is worth real money. It is also worth checking whether your licence to alter requires removal at all. Some landlords would rather keep good glass office partitioning as an improvement than ask a departing tenant to strip it out.

When we tell people not to use glass

We would rather lose a job than install the wrong thing in it.

• Rooms that need genuine speech privacy. Build those solid and spend the saving on better glass elsewhere.
• Walls that need to take fixings. You cannot hang a whiteboard, a television bracket, shelving or a kitchen unit on a glass partition. If the room plan depends on wall space, you need a wall.
• Buildings where the glass physically cannot get in. If the goods lift car is smaller than the pane and there is no stair route, the design has to change. It is far better to find that out at survey than on delivery morning.
• Very small rooms. A 1.8 metre square glass box reads like a fish tank and nobody volunteers to sit in it. Part-height glazing over a solid dado almost always works better.

Everything else is fair game. Most offices in London would be better lit, better supervised and easier to re-let with glass partitioning than without it, and a properly specified system will outlast two or three tenancies.